JPH05307915A - Fire resisting electrical wire - Google Patents

Abstract

PURPOSE:To always provide a sufficient electrical insulation property by forming a fire resisting layer by means of a synthetic collected mica tape containing a carbonization preventive mainly consisting of a synthetic collected mica or a mixed collected mica tape obtained by mixing a synthetic rubber more than a certain specified weight percentage in a natural mica. CONSTITUTION:A synthetic collected mica tape 2 is manufactured by bonding its synthetic collected mica 2a, impregnated with a silicone resin, for example, in which an aluminum hydroxide of 10 weight per cent is contained in a silicone resin of 100 weight per cent, to a lining member 2b by means of a material in which a aluminum hydroxide of 20 weight per cent is contained in a silicone resin of 100 weight per cent. The tape 2 is wound about a copper wire having a predetermined diameter so as to be wrapped by for example, its half width in such a manner that the mica 2a makes contact with the copper wire. Similarly, the synthetic collected mica tape 2' is wound about the tape 2 so as to be wrapped in such a manner that the mica 2a of the mica tape 2' makes contact with the lining member 2b made of a glass cloth of the tape 2. An insulating layer 3 is provided on fire resisting layers of the tape 2 and 2' and a sheath layer 4 is provided on the layer 3 to form a fire resisting layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fireproof electric wire, and more particularly to improvement of the fireproof layer of the fireproof electric wire, and more particularly to a fireproof electric wire having a fireproof layer which exceeds the standard performance of the Fire Service Agency.

[0002]

2. Description of the Related Art In recent years, an emergency power source has been secured for enabling emergency blame alarms or indoor broadcasts even when a fire occurs.

For the purpose of securing this emergency power source,
BACKGROUND ART Fire-resistant electric wires have been used in which a laminated mica tape made of natural mica that is resistant to high temperatures and has excellent insulation properties is wound around a conductor.

As an example of the above fireproof electric wire, a conventional sectional view thereof is shown in FIG. In FIG. 4, mica tapes 5 and 5'mainly composed of soft mica made of natural mica are wound on the conductor 1 to form a fire resistant layer.

An insulating layer 3 made of polyethylene or the like is provided on the two-layer fireproof layer thus wound on the conductor 1.
For example, a fireproof electric wire was formed by providing a sheath layer 4 made of polyvinyl chloride or the like on it.

There is a standard for the performance of the above-mentioned fireproof wire according to the notification of the Fire Department. That is, the standard is to raise the temperature from normal temperature to 840 ° C. in 30 minutes in the combustion furnace specified by the above notification in 30 minutes, during which the withstand voltage of 600 V and the insulation resistance of 0.4 MΩ or more are set. The ability to hold is required.

[0007]

However, in an actual fire, there may be a case where the temperature exceeds 840 ° C, and the atmosphere in which oxygen in the air is diluted is generated. High temperature, eg J
As shown in FIG. 4, when ISA 1304 is heated for 1 hour (room temperature to 925 ° C. for 1 hour) and the oxygen in the air is diluted, for example, inside a metal conduit tube, as shown in FIG. A fire resistant wire with a fire resistant layer formed by mica tapes 5 and 5'mainly composed of soft laminated mica can satisfy the insulation performance of 0.4 MΩ or more according to the standards of the Fire Service Agency mentioned above. There wasn't. The cause of this decrease in insulation resistance is carbonization of the adhesive agent and carbonization of the backing material that are impregnated in the assembled mica due to lack of oxygen in the air, and that the hydrogen group (OH ^- group) possessed by natural mica is By chemically changing to water,
It was found that the natural mica was dehydrated at about 650 ° C. in the case of hard mica, and dehydrated at about 800 ° C. in the case of soft mica, and the decrease in insulation resistance was caused by the change in its crystal structure.

The present invention has been made in view of the above points, and provides a fireproof electric wire having excellent heat resistance and insulation even in a situation where oxygen in the air is dilute at a high temperature of 840 ° C., which is announced by the Fire Service Agency. It is intended to be provided.

[0009]

In order to achieve the above object, the fire resistant electric wire of the present invention comprises a conductor, on which a fire resistant layer, an insulating layer and a sheath layer are sequentially provided, and fine mica flakes of synthetic mica are used as the fire resistant layer. In the synthetic laminated mica tape constituted by adhering a backing material with an adhesive to a synthetic laminated mica obtained by papermaking, a layer of the synthetic laminated mica, an adhesive layer between the synthetic laminated mica and the backing material, and a backing material A synthetic assemblage mica tape containing an anti-carbonizing agent in at least one or more of the layers is configured to be wound onto the conductor. Also, as the refractory layer, in a mixed mica laminated mica tape constituted by adhering a backing material with an adhesive to a laminated mica in which at least 20% by weight of synthetic mica is mixed with natural mica, the layer of the mica laminated and the mica laminated An adhesive layer between the backing material and the backing material, and a mixed paper composite mica tape containing an anti-carbonizing agent in at least one layer of the backing material may be wound around the conductor. ..

[0010]

In the fireproof electric wire of the present invention, since the synthetic mica and the carbonization inhibitor are used in the fireproof layer, the synthetic mica having a stable structure up to about 1000 ° C. and the carbonization for preventing the carbonization of the adhesive and the backing material. Due to the action with the inhibitor, high insulating properties are maintained at a high temperature of more than 840 ° C. and even when the oxygen in the air is lean.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view of an embodiment of the fireproof electric wire according to the present invention. In FIG. 1, 1 is a conductor,
Reference numerals 2 and 2 ′ are synthetic mica tapes molded from synthetic mica, backing material and carbonization inhibitor. Then, place the synthetic mica tape 2 or 2'onto the conductor 1 above.
A fireproof layer composed of two layers is formed by winding while wrapping so as to overlap each other by / 2 width. 3 is an insulating layer such as polyethylene, and 4 is a sheath layer such as polyvinyl chloride. The synthetic mica tapes 2 and 2 ′ each have the structure shown in FIG.

In FIG. 2, 2a is a synthetic mica, 2
b is a backing material, 2c is an adhesive, 2d is aluminum hydroxide
Is. The synthetic mica 2a is a synthetic mica, that is, heaven.
The hydroxyl group (OH ^-Group) chemical bond strength
Strong fluorine group (F^-Group). For example
Fluorine gold mica KMg₃(AlSi₃O₃) F₂And fluorine
Fine particles obtained by crushing fluorine mica such as tetrasilicon mica
Synthesized from fine mica scales or talc and fluorinated compounds
It is obtained by paper-making the fine mica scales.

The synthetic mica 2a forming the synthetic mica layer is impregnated with silicone resin, organic and inorganic adhesives such as polyamide, polyimide and polyolefin, and as a reinforcing material thereof, for example, polyethylene film and polypropylene, A plastic film or sheet such as polyester or nylon, or a backing material 2b such as natural fiber and glass cloth or glass yarn is bonded with an adhesive 2c to form a backing material layer and an adhesive layer, respectively. As the adhesive 2c for forming the adhesive layer, silicone resin, polyamide, polyimide, polyolefin or the like having a high insulation resistance, which is impregnated in the layer of the synthetic mica 2a, is used.

At least one layer of the synthetic mica 2a, the backing material 2b and the adhesive 2c contains a carbonization inhibitor. As the anti-carbonizing agent, for example, aluminum hydroxide 2d is an adhesive that is impregnated in the synthetic mica 2a, an organic adhesive 2c that bonds the synthetic mica 2a and the backing material 2b, or a backing material. The organic reinforcing material of 2b or the reinforcing material containing an organic substance has an effect of preventing carbonization of each organic substance under the condition of lack of oxygen in the air at high temperature.

Under a condition of lack of oxygen in the air at high temperature, the organic substance tends to be carbonized, and if carbonized, it becomes conductive and the insulation resistance is lowered. It acts to prevent carbonization.

Next, in order to compare the performance of the insulation resistance test between the examples of the present invention and the conventional example, Examples A and B of the fireproof electric wire according to the present invention and the conventional examples C to E were performed as follows. Created.

(1) Example A of Fire Resistant Electric Wire of the Present Invention Synthetic laminated mica tape 2 had a silicone resin content of about 4% containing 100 parts by weight of aluminum hydroxide and 10 parts by weight of aluminum hydroxide. Impregnated thickness about 0.
A synthetic resin mica 2a having a thickness of 12 mm and a backing material 2b made of a glass cloth having a thickness of 0.03 mm are bonded to 100 parts by weight of a silicone resin with a silicone resin containing 20 parts by weight of aluminum hydroxide. Then, the synthetic mica tape 2 is wrapped around a copper wire having a diameter of 22 mm (conductor 1 shown in FIG. 1) so that the synthetic mica 2a is in contact with the copper wire and is wrapped by 1/2 width. .. Further, the synthetic mica tape 2 on the synthetic mica tape 2
The synthetic mica tape 2 ′ of the synthetic mica tape 2 ′ formed in the same manner as described above is wrapped and wound in 1/2 width so that the synthetic mica tape 2 a is in contact with the backing material 2 b made of glass cloth of the synthetic mica tape 2. In this way, the insulating layer 3 made of polyethylene having a thickness of 1.2 mm is provided on the refractory layer formed by the two-layer synthetic laminated mica tapes 2 and 2 ', and the insulating layer 3 having a thickness of 1.5 mm is formed on the insulating layer 3. Sheath layer 4 made of vinyl chloride
The fireproof electric wire subjected to the above is Example A of the present invention.

(2) Example B of Fire Resistant Electric Wire of the Present Invention Example B is a synthetic laminated mica 2a in the above Example A.
The main component of the above was synthetic mica (fluorinated gold mica), while the synthetic mica was mixed with 20% by weight of synthetic mica in place of the synthetic mica, and the mica obtained was used in the above-mentioned Example. It is formed similarly to A.

(3) Example C of conventional fireproof electric wire The conventional example C is the synthetic laminated mica 2a in the above example A.
In contrast to the synthetic mica as the main component of the above, the synthetic mica is formed in the same manner as in the above-mentioned Example A by using soft mica which is a natural mica.

(4) Example D of Conventional Fire Resistant Electric Wire In the conventional example D, a thickness in which the synthetic resin mica tape in the above example A is replaced with a silicone resin containing no aluminum hydroxide as a carbonization inhibitor is used. A synthetic mica tape having a synthetic lining mica having a thickness of about 0.12 mm and a glass cloth having a thickness of 0.03 mm adhered with a silicone resin is used in the same manner as in Example A above.

(5) Conventional Fireproof Wire Example E In the conventional example E, instead of the synthetic laminated mica tape in the conventional example D, a mica tape mainly composed of soft laminated mica which is natural mica is used. It is formed in the same manner as in Example A above.

In this way, with respect to the fireproof electric wires of the example of the present invention and the conventional example thus obtained, the change of the electric insulation performance during heating under the condition of lack of oxygen in the air was examined. In the electrical performance test, as shown in FIG. 5, the refractory electric wires 8 of the example of the present invention and the conventional example are respectively passed through the metal conduit tube 6, and the voids at both ends are filled with an aluminum oxide-based inorganic filler 7
JI shown in Fig. 6 in a combustion furnace in a state close to sealed by
92 according to the heating temperature curve of S A 1304
Heat to 5 ° C. for 1 hour.

The state of change in the insulation resistance during this period was measured as shown in the insulation resistance curve diagram of FIG. 3, in which A, B, C, D, and
Each curve marked with E is the above-mentioned embodiment A, B of the present invention.
And the fireproof electric wires of Conventional Examples C, D, and E, respectively.

As is apparent from FIG. 3, the refractory electric wires of Examples A and B according to the present invention are A, B even in the metal conduit tube 6 in the condition of oxygen deficiency in the air at a high temperature of 925.degree.
As shown by the curve, the insulation resistance is maintained at 0.4 MΩ or more. On the other hand, the conventional refractory wire indicated by the curves of C, D and E is 30 minutes to 1 hour after heating, that is, 840 ° C.
Insulation resistance falls below 0.4 MΩ between 925 and 925 ℃. This difference is not only in Example E of the fire resistant electric wire using the mica tape of the natural laminated mica at high temperature under the condition of lack of oxygen in the air, but also the synthetic laminated mica of the synthetic laminated mica which has excellent electric insulation performance at high temperature. Also in Example D of the fireproof electric wire using the tape, the insulation resistance is greatly reduced,
A reduction in insulation resistance is also seen in Example C of a fireproof electric wire using a mica tape containing aluminum hydroxide in natural laminated mica.

It has been shown that a fire resistant wire using a synthetic mica tape that is a combination of synthetic mica that is thermally stable at high temperatures and aluminum hydroxide that prevents carbonization of organic substances can maintain an insulation resistance of 0.4 MΩ or more. ing.

Further, as is clear from FIG. 3, the fire resistant wire of the present invention relating to the corresponding fire resistant wire can be evaluated from the characteristic curves of both A and B. It has been confirmed by experiments that it has passed all the items of withstanding a voltage of 600 V, having an insulation resistance of 0.4 MΩ or more immediately after the end of heating, and withstanding a voltage of 1500 V for 1 minute immediately after the end of heating. It was

Therefore, the fireproof electric wire of the present invention is a fireproof electric wire having excellent heat resistance and insulation resistance, which is sufficient to sufficiently maintain the standards set forth by the Fire Agency, even at a high temperature of 925 ° C. and in a state of insufficient oxygen. As the anti-carbonizing agent, aluminum hydroxide 2
magnesium hydroxide replaced with d, aluminum silicate,
Magnesium silicate has a similar tendency, and the magnesium hydroxide or the like can be used as a carbonization inhibitor. Further, the above-mentioned Example A of the present invention is a fire resistant electric wire in which a synthetic refractory mica, a backing material, and a synthetic refractory mica tape formed of a carbonization inhibitor are wound in two layers to form a refractory layer. Example B of the invention is a composite mica obtained by mixing synthetic mica with natural mica in an amount of at least 20% by weight, a composite mica tape composed of a backing material and an anti-carbonizing agent, which is wound in two layers for fire resistance. Although it is a fireproof electric wire in which a layer is formed, the present invention is not limited thereto, and the fireproof layer may be formed by one layer as long as it has a sufficient thickness. The synthetic laminated mica tape in Example A of the invention and the mixed paper laminated mica tape in Example B of the present invention may be formed as a single layer to form a refractory layer.

[0028]

As described above, according to the present invention, synthetic mica tape mainly containing synthetic mica and containing an anti-carbonizing agent, or natural mica mixed with at least 20% by weight of synthetic mica is obtained. Since the refractory layer is composed of the mixed paper laminated mica tape containing the anti-carbonizing agent mainly composed of the laminated mica, in an actual fire, the ventilation is insufficient at a high temperature exceeding 840 ° C, Alternatively, even when an oxygen deficiency occurs in an atmosphere in which a large amount of combustible substances are present, sufficient electric insulation performance is exhibited.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a fireproof electric wire according to the present invention.

FIG. 2 is a cross-sectional view of an example of a fireproof tape forming a fireproof layer of the fireproof wire shown in FIG.

FIG. 3 is an insulation resistance comparison curve diagram of an embodiment of a fire resistant electric wire of the present invention and a conventional one.

FIG. 4 is a cross-sectional view showing a structure of a conventional fire resistant wire.

FIG. 5 is a cross-sectional explanatory diagram when a metal conduit is passed through.

FIG. 6 is a heating temperature curve diagram defined in Japanese Industrial Standard JIS A 1304.

[Explanation of symbols]

 1 Conductor 2, 2'Synthetic Integrated Mica Tape 2a Synthetic Integrated Mica 2b Backing Material 2c Adhesive 2d Aluminum Hydroxide (Anticarbonization Agent) 3 Insulating Layer 4 Sheath Layer 5 Mica Tape 6 Metal Conduit Tube 7 Inorganic Filler 8 Fire Resistant Electric Wire

Claims (2)

[Claims] 1. A fire resistant electric wire comprising a conductor, a fire resistant layer, an insulating layer, and a sheath layer sequentially provided on the conductor, wherein the fire resistant layer is composed of a synthetic laminated mica tape of a synthetic laminated mica, a backing material and an anti-carbonizing agent. Fire resistant electric wire characterized by being 2. A refractory electric wire comprising a conductor on which a refractory layer, an insulating layer, and a sheath layer are sequentially provided, wherein the refractory layer is made of natural mica and at least 2 synthetic mica.
A fire-resistant electric wire, which is composed of a composite mica mixed with 0% by weight or more, a backing material and a carbonization inhibitor mixed mica tape.