JPH07161230A - Flame retardant composition, electric wire, and cable - Google Patents

Abstract

PURPOSE:To provide a flame retardant composition, in which a hygroscopic properLy is suppressed, and to provide an electric wire and a cable utilizing it. CONSTITUTION:A natural mineral mainly consisting of magnesium hydroxide is ground, and a surface finishing agent mainly consisting of at least one kind of compound selected from fatty acid, fatty acid metallic salt, a silane coupling agent, and a titanate coupling agent is added in the proportion of 0.5-5% by weight to the natural mineral for surface treatment, and then, the natural mineral, on which surface treatment is carried out, is added to plastic or rubber. In this way, hygroscopicity can be suppressed while flame retardancy is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant composition which does not generate hydrogen halide gas at the time of combustion and has suppressed hygroscopicity, and an electric wire and a cable provided with a coating layer of the flame-retardant composition. It is a thing.

[0002]

2. Description of the Related Art Smoke generation, toxicity when burning electric wires and cables,
For the purpose of preventing secondary disasters such as corrosion, for example, JP-A-1-
As disclosed in Japanese Patent No. 141929, magnesium hydroxide is used as one of the flame retardants that impart flame retardancy to the coating material.

[0003]

Magnesium hydroxide conventionally used is made from magnesium in seawater as a raw material. The flame-retardant composition using this as a flame retardant absorbs moisture when left in high-humidity air, and when covering electric wires and cables, moisture absorbed in the extruder foams, resulting in poor appearance. was there.

[0004]

The present invention solves the above-mentioned problems and provides a flame-retardant composition having suppressed hygroscopicity, and an electric wire and cable using the same. A natural mineral containing magnesium as a main component is ground, and a surface treatment agent containing at least one selected from fatty acids, fatty acid metal salts, silane coupling agents, and titanate coupling agents as a main component is added to the above natural mineral. A flame-retardant composition which is added to plastic or rubber after surface treatment by adding 0.5 to 5% by weight to impart flame retardancy and suppress hygroscopicity, and a coating layer of the flame retardant composition There are electric wires and cables on the wire.

[0005]

[Function] In order to solve the above-mentioned problems, studies were conducted using various magnesium hydroxides. Magnesium hydroxide made from a natural mineral containing magnesium hydroxide as a main component was excellent in suppressing hygroscopicity. I found that. Although this mechanism is unclear, it may be because the crystal structure is different from that of conventional products.
The amount of the surface treatment agent added was defined as 0.5 to 5% by weight, because the effect of the surface treatment is not shown when the amount is less than 0.5% by weight.
This is because if it exceeds the weight percentage, it is not preferable in terms of cost.

[0006]

[Examples] Various materials shown in Table 1 were kneaded with a 6-inch open roll for 15 minutes, and then mixed with a pelletizer to about 3 mm x 3 mm x
The pellets were processed into 3 mm pellets and the hygroscopicity was evaluated. The results are shown in Table 1.

The surface treatment method was performed as follows. (1) Stir magnesium hydroxide in a super mixer. (2) While stirring magnesium hydroxide, the surface treatment agent is gradually added over about 5 minutes. (3) After adding all of the surface treatment agent, stir for about 20 minutes.

The brands of the plastic material and the magnesium hydroxide surface treatment agent used are as follows. EEA: Nippon Unicar WN-170 Magnesium hydroxide A: Conventional (seawater method) magnesium hydroxide Example, Kyowa Chemical Kisuma 5B: Conventional (seawater method) magnesium hydroxide Example, Kyowa Chemical Kisuma 5B C: Natural mineral (blue) Magnesium hydroxide surface-treated with silane coupling agent as raw material (Example), Kamijima Chemical Magsee's N-1 Silane coupling agent = Shin-Etsu Chemical 0.1 wt% D: Same as above, hydroxylated with silane coupling agent Magnesium Example, silane coupling agent = Shin-Etsu Chemical Addition amount = 0.5% by weight E: Magnesium hydroxide surface-treated with fatty acid Fatty acid = stearic acid Addition amount = 0.5% by weight F: Water surface-treated with fatty acid metal salt Magnesium oxide Example, fatty acid metal salt = zinc stearate Addition amount = 0.5% by weight

[0009]

[Table 1]

The moisture absorption amount was measured as follows.
100 g of the pellet was sampled from the above sample, left in a desiccator having a humidity of 70%, and the water content at each time was measured. The water content was measured with a Karl Fischer water content meter. The ones using the conventional magnesium hydroxide shown in Comparative Examples 1 and 2 have a large water content of about 300 ppm even after 1 day, and about 30 days after about 30 ppm.
It increased to 1400ppm. The comparative example is an example where the surface treatment is performed using a natural mineral, but since the amount of the surface treatment agent is small,
The same tendency as Comparative Examples 1 and 2 was shown. On the other hand, in Examples 1 to 3, the water content after one day was as small as about 100 ppm,
Even after 30 days, the amount of water increased only up to about 350 to 400 ppm, and it was confirmed that the hygroscopicity was low.

The case where EEA is used as the material has been shown above, but ethylene propylene rubber, acrylic rubber, ultra low density polyethylene, linear low density polyethylene, ethylene vinyl acetate, ethylene methacrylate, ethylene methyl methacrylate, etc. Similar effects were observed in rubber and plastic materials, and also in a mixture thereof, and it was confirmed that magnesium hydroxide made from a natural mineral had a low hygroscopic property.

[0012]

As described above, according to the flame-retardant composition of the present invention, an electric wire having a low hygroscopicity, a good appearance without requiring a drying step during the production of the electric wire or cable,
Cables can be made.

Claims (2)

[Claims] 1. A surface-treating agent containing at least one selected from fatty acids, fatty acid metal salts, silane coupling agents and titanate coupling agents as a main component, which is obtained by crushing a natural mineral containing magnesium hydroxide as a main component. A flame-retardant composition comprising 0.5 to 5 wt% of the above-mentioned natural mineral, surface-treated and added to plastic or rubber to impart flame retardancy and suppress hygroscopicity. 2. An electric wire or cable comprising a coating layer of the flame-retardant composition according to claim 1.