JP3118137B2 - Fire resistant wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fire-resistant electric wire capable of greatly improving withstand voltage performance without reducing insulation resistance when exposed to high heat or flame due to a fire or the like.

[0002]

2. Description of the Related Art Generally, in places where a large number of people gather, such as theaters and department stores, in the event of a fire or the like, an evacuation guide light such as an emergency exit guide light or the like is used to safely guide people in the hall to an emergency exit. It is required that the light is kept on for a certain period of time so that the evacuation is completed. Therefore, the Japan Electric Wire & Cable Makers Association has voluntarily established its own certification standards for fire-resistant electric wires, etc. used for the wiring of fire-extinguishing equipment, alarm equipment, and evacuation equipment for fire-resistant objects, etc. The quality of materials is being ensured.
In this specification, the term “fireproof electric wire” refers to a general term for cables having fireproof performance specified in the Fire Service Agency Notification No. 7 of 1978. This refractory wire has a configuration as shown in FIG. That is, in the fire-resistant electric wire 1, a refractory layer 3 is formed on the outer periphery of the conductor 2, the outer periphery is covered with an insulator 4 made of polyethylene, and a sheath 5 made of polyvinyl chloride resin or polyethylene resin is further provided on the outer periphery. It is configured by coating.

[0003] The fireproof layer 3 includes a composite fireproof tape 8 in which a mica tape 7 is integrated with a glass tape 6 made of an inorganic material such as a glass fiber cloth as shown in FIG. The glass tape 6 is, for example, 900
This is a cloth fabric in which yarns before and after denier are arranged in rows and columns 30 to 60 lines / inch. Alternatively, as shown in FIG.
As shown in FIG. 1, there is a composite fire-resistant tape 10 in which a laminated mica tape 7 is bonded to a plastic film 9 to be integrated. The plastic film 9 has a thickness of, for example, 10 μm.
It is formed of PE, PP, PET or the like having a thickness of about 25 μm. The laminated mica tape 7 is formed by laminating scale-like mica foil with a silicone resin and laminating the same to form a tape. Scaly mica foil is suitable for handling because the synthetic mica is scaly, but as it is expensive,
A scale-like natural mica is used. Note that, as synthetic mica, fluorine mica containing talc as a main component is suitable. The silicone resin is an organosilicon compound, which forms a network bond by hydrolysis and polycondensation of organohalogenosilane (R ₂ SiX ₂ ) to obtain a resinous material.
The properties of this silicone resin are extremely excellent in heat resistance and moisture resistance, and also excellent in electrical insulation performance.

In the conventional fire-resistant electric wire 1, a composite fire-resistant tape 8 (10) having a total thickness of 0.1 mm to 0.2 mm and cut to an appropriate width is formed on a fireproof layer 3 provided on the conductor 2 for 2 to 2 mm. Four sheets were used and formed. As a forming method, the composite fire-resistant tape 8 (10) was vertically attached to the conductor 2 or wrapped. Conventionally, the fire-resistant electric wire 1 formed by superposing and winding the composite fire-resistant tape 8 (10) around the conductor 2 has a structure shown in FIGS.
As shown in FIG. 3, a composite fire-resistant tape 8 (10) is placed on the conductor 2.
And the composite fire-resistant tape 8 (10) is １ ／ wrapped on the wrapped composite fire-resistant tape 8 (10) to form a two-layer structure. The overlap of the composite fire-resistant tape 8 (10) is indicated by a in FIG. b indicates the tape width of the composite fire-resistant tape 8 (10). The ratio of the tape width b to the overlap margin a is a: b = 1: 2. The insulator 4 is extruded and coated on the composite fire-resistant tape 8 (10) wound on the conductor 2 and the sheath 5 is further coated on the insulator 4. Second, as shown in FIGS. 14 to 16, a composite fire-resistant tape 8 (10) is wrapped 1/6 over the conductor 2, and the composite fire-resistant tape 8 (10) is laid over the wrapped composite fire-resistant tape 8 (10). 8 (10)
Is formed in a two-layer structure by winding 1/6 in an overlapped manner. The overlapping margin of the composite fire-resistant tape 8 (10) is shown in FIG.
This is indicated by c in FIG. d is a composite fire-resistant tape 8 (10)
Indicates the tape width. Overlap this tape width d with c
Is c: d = 1: 6. The insulator 4 is extruded and coated on the composite fire-resistant tape 8 (10) wound on the conductor 2 and the sheath 5 is further coated on the insulator 4.

[0005]

However, when the cross section of the refractory layer 3 wound on the conductor 2 of the conventional refractory wire 1 is viewed, as shown in FIGS. It is constituted by the fire resistant tape 8 (10).
In particular, in the overlapping portion F where the fire-resistant layer 3 is composed of two composite fire-resistant tapes 8 (10), the composite fire-resistant tape 8 (1) is formed by the winding pressure when the composite fire-resistant tape 8 (10) is wound.
The mica foil of the mica tape 7 constituting 0) is subjected to so-called "bullying" in which a crack (crack) 11 is generated by the tightening pressure of the composite fire-resistant tape to be superimposed.

For this reason, in the conventional fire-resistant electric wire 1,
From the cracks 11 in the overlapping portion F of the composite fire-resistant tape 8 (10) wound on the conductor 2, the fire-resistant electric wire 1 is exposed to high heat or a flame due to a fire or the like, and is melted by the insulator 4 and the sheath 5 Penetrates in the direction of the conductor 2 and becomes conductive carbide due to incomplete combustion, causing a decrease in insulation resistance as a fire-resistant electric wire, and has a problem that withstand voltage is extremely deteriorated.

An object of the present invention is to provide a composite fire-resistant tape that is wound around a conductor without causing cracks in the overlapped portion. Even if the insulator or sheath is melted by being exposed to high heat or a flame due to a fire or the like, Even if the melt of the insulator and the sheath does not enter the conductor direction, even if the melt of the insulator and the sheath becomes conductive carbide due to incomplete combustion, the insulation resistance of the fire-resistant wire does not decrease. And to prevent a decrease in withstand voltage.

[0008]

According to the first aspect of the present invention,
A composite fire-resistant tape integrated with a mica tape laminated with a glass tape or a synthetic resin tape on the conductor,
The second winding portion is wound on the first winding portion, and the third winding portion is wound on the second winding portion so as to overlap a part of the first winding portion. An insulating material is extruded and coated on the wound composite fire-resistant tape to form a fire-resistant electric wire.

According to a second aspect of the present invention, there is provided a composite fire-resistant tape obtained by bonding a glass tape or a synthetic resin tape to a laminated mica tape and integrating the mica tape with the conductor and the insulator.
A refractory electric wire is formed by winding and interposing a 重 ね 1.3 / 2 layer.

[0010]

According to the first aspect of the present invention, a composite fire-resistant tape obtained by laminating a glass tape or a synthetic resin tape on a mica tape on a conductor and integrating the mica tape on the conductor is provided on the first winding portion. A winding is formed and a first winding is formed over the second winding.
Are wound so that a third winding part overlapping with a part of the winding part is formed. Then, an insulator is extruded and coated on the composite fire-resistant tape. With such a configuration, a three-layer state is obtained in which three end portions of the overlapped layer in which the composite fire-resistant tape is overlapped and wound are stacked. As described above, since the portion exposed to the outside of the superimposed layer is overlaid on the two superposed layers of the first wound portion and the second wound portion, the lower layer is formed at the end portion of the superimposed layer. Pressing does not occur, and cracks can be prevented from being generated in the overlapping portion of the composite fire-resistant tape wound on the conductor.

[0011] Further, in order not to cause a crack in the overlapped portion of the composite fire-resistant tape, even if the insulator and the sheath are melted by being exposed to high heat or a flame due to a fire or the like, the melted material of the insulator and the sheath enters the conductor direction. Therefore, even if the melt of the insulator and the sheath becomes conductive carbide due to incomplete combustion, the insulation resistance of the fire-resistant wire does not decrease. In addition, it is possible to prevent a decrease in the withstand voltage of the fireproof electric wire.

According to the second aspect of the present invention, a composite fire-resistant tape obtained by laminating a mica tape and a glass tape or a synthetic resin tape on a conductor to form an integrated fire-resistant tape is used.
1. Winding in 3/2 laps. An insulator is extruded and coated on the composite refractory tape. With such a configuration, a three-layer state is obtained in which three end portions of the overlapped layer in which the composite fire-resistant tape is overlapped and wound are stacked. As described above, since the end portion of the overlapping layer is overlaid on the two layers, the lower layer is not pressed at the end portion of the overlapping layer, so that the composite fire-resistant tape wound on the conductor is not required. No cracks are formed in the overlapping portion.

Further, in order not to cause cracks in the overlapped portion of the composite fire-resistant tape, even if the insulator and the sheath are melted by being exposed to high heat or a flame due to a fire or the like, the melted material of the insulator and the sheath enters the conductor direction. Therefore, even if the melt of the insulator and the sheath becomes conductive carbide due to incomplete combustion, the insulation resistance of the fire-resistant wire does not decrease. In addition, it is possible to prevent a decrease in the withstand voltage of the fireproof electric wire.

[0014]

[0015]

Embodiments of the present invention will be described below. 1 to 3 show one embodiment of the fireproof electric wire according to the present invention . In the figure, a total thickness of 0.1 mm
Composite fire-resistant tape 8 (1 mm
0), the second winding 8B (10B) overlaps the first winding 8A (10A), and the second winding 8B (1
0B), a third winding 8C (10C) is wound so as to overlap a part of the first winding 8A (10A). This composite fire resistant tape 8
The superposition of the first winding portion 8A (10A) and the second winding portion 8B (10B) in (10) is specifically described in 1.1.
/ 2 to 1.3 / 2. The overlap of the composite fire-resistant tape 8 (10) is indicated by A in the figure. B indicates the tape width of the composite fire-resistant tape 8 (10). The ratio of the tape width B to the overlap margin A is A: B = 1.1 (〜1.3): 2. The insulator 4 is extruded and coated on the composite fire-resistant tape 8 (10) wound on the conductor 2 and the sheath 5 is further coated on the insulator 4. When the composite fire-resistant tape 8 (10) is wound in a stack of 1.1 / 2 to 1.3 / 2 in this manner, the end portion of the overlapped layer in which the composite fire-resistant tape 8 (10) is overlapped is wound as shown in FIG. The width of / 20 to 3/20 further overlaps, the second winding 8B (10B) overlaps the first winding 8A (10A), and the second winding 8B (10B) On the third winding 8C
(10C) and three layers of the composite fire-resistant tape 8 (10) are superposed. As described above, the end C portion of the superimposed layer is further overlapped on the two layers, so that the lower composite fire-resistant tape 8 (10) is not pressed by the end portion of the superimposed layer, Cracks do not occur in the overlapping portion of the composite fire-resistant tape 8 (10) wound on the conductor 2. In order to prevent a crack from being generated in the overlapping portion of the composite fire-resistant tape 8 (10), even if the insulator 4 and the sheath 5 are melted by being exposed to high heat or a flame due to a fire or the like, the insulator 4, the sheath 5 may be melted.
Does not enter the conductor 2 direction, and even if the melt of the insulator 4 and the sheath 5 becomes a conductive carbide due to incomplete combustion, the insulation resistance of the fire-resistant wire 1 may be reduced. Absent. In addition, it is possible to prevent a decrease in withstand voltage of the fire-resistant electric wire 1.

FIGS. 4 to 6 show other examples of the fireproof electric wire according to the present invention .
Embodiment is shown. In the figure, on the conductor 2,
A first composite fire-resistant tape 8 (10) having a total thickness of 0.1 mm to 0.2 mm and cut to an appropriate width is wound in a 1.1 / 2 to 1.3 / 2 lap. This first composite fire-resistant tape 8 (1
The overlap of 0) is indicated by A in the figure. B indicates the tape width of the first composite fire-resistant tape 8 (10). The ratio of the tape width B to the overlap margin A is A: B = 1.1 (〜1.3): 2. Further, the second composite fire-resistant tape 8 (10) is １ ／ lap-wrapped on the wrapped first composite fire-resistant tape 8 (10) to form a two-layer structure. The overlap of the second composite fire-resistant tape 8 (10) is indicated by D in the figure. E indicates the tape width of the second composite fire-resistant tape 8 (10). The ratio between the tape width E and the overlap margin D is D: E = 1: 4. The tape width E of the second composite fire-resistant tape 8 (10) may be different from or the same as the tape width B of the first composite fire-resistant tape 8 (10). Absent. This first composite fire-resistant tape 8 (10)
Composite fire-resistant tape 8 (1
0), the insulator 4 is extruded and coated.
Is covered with a sheath 5.

As described above, the first composite fire-resistant tape 8 (1
0) is wound in 1.1 / 2 to 1.3 / 2 laps,
As shown in FIG. 6C, the end portion of the overlapping layer is 1 /
20 to 3/20 are further overlapped to form a three-layer state in which three sheets are overlapped. Since the end portion C of the layer to be overlapped is further overlapped on the two layers, the end of the composite fire-resistant tape 8 (10) on the overlapped layer has a lower composite fire-resistant tape 8 (10). 10) is not pressed, and no crack is generated in the overlapping portion of the first composite fire-resistant tape 8 (10) wound on the conductor 2. Further, since the second composite fire-resistant tape 8 (10) is further wound over the first composite fire-resistant tape 8 (10), the overlapping portion of the second composite fire-resistant tape 8 (10) is 5 mm. It becomes a state where the sheets are stacked, and the fire resistance can be further improved. In this way, the second composite fire resistant tape 8 (10)
Because the composite fire-resistant tape 8 (10) is wrapped around,
Even if the insulator 4 and the sheath 5 are melted by being exposed to high heat or a flame due to a fire or the like, the molten material of the insulator 4 and the sheath 5
Therefore, even if the melt of the insulator 4 and the sheath 5 becomes conductive carbide due to incomplete combustion, the insulation resistance of the fire-resistant wire 1 does not decrease. In addition, it is possible to prevent a decrease in withstand voltage of the fire-resistant electric wire 1. The weak part of the fireproof layer 3 (two fireproof tapes)
, It is possible to obtain an inexpensive fire-resistant electric wire whose insulation resistance value and withstand voltage value have been greatly improved and the quality is stable as compared with the related art.

Table 1 shows the characteristic test results of the characteristics of the fire-resistant electric wire according to the present invention and the characteristics of the conventional fire-resistant electric wire. The fire-resistant electric wire of the example used in the characteristic test was prepared by winding a first composite fire-resistant tape having a thickness of 0.15 mm and a width of 12 mm on a conductor having a diameter of 2.0 mm in 1.1 / 2 layers. 0.15mm thick x 1 on the composite fire resistant tape
Wrap a 2 mm wide second composite fire-resistant tape in 1/4 laps,
A flat cable formed by coating an insulator on the second composite fire-resistant tape by extrusion and then coating a non-halogen PE sheath by extrusion has a length of 1.3 m. Further, the conventional fire-resistant electric wire has a diameter of 2.0 mm.
A 0.15 mm thick × 12 mm wide first composite fire-resistant tape is wound on a 1/2 mm conductor in a 重 ね lap, and a 0.15 mm thick × 12 mm wide second composite fire-resistant tape is further wound on the first composite fire-resistant tape. The composite fire-resistant tape of No. 1 was wound in a 1/4 lap, an insulator was coated on the second composite fire-resistant tape by extrusion, and then a flat cable formed by extruding a non-halogen PE sheath by 1.3 m was formed. Is the length of The material and thickness of the insulator and the non-halogen PE sheath are the same for both the embodiment and the conventional example.

This characteristic test was carried out by placing a refractory wire horizontally in a heating furnace in both the examples and the conventional example, and placing both ends of the refractory wire in contact with the inside wall surface of the heating furnace. This heating furnace is heated by a gas burner, and heats the inside of the furnace up to 840 ° C. in 30 minutes in accordance with a temperature curve defined in JIS A 1304. The heating start temperature of the sample is 200 ° C. or less.

Table 1 In the test conditions in the insulation resistance measurement test in Table 1,
“Before heating (MΩ · 1.3 m)” means that after being placed in a heating furnace, the insulation resistance between the conductor and the fixed wire was measured at room temperature with a DC 500 V / 100 MΩ insulation resistance measuring instrument. It is a resistance value (the unit is MΩ). The term “heating 30 minutes (MΩ · 1.3 m)” means that the insulation resistance value between the conductor and the fixed wire when placed in a heating furnace and heated to 840 ° C. in 30 minutes is a direct current. It is a resistance value (unit: MΩ) determined by measuring with an insulation resistance measuring instrument of 500 V / 100 MΩ.

In the test conditions of the dielectric strength measurement test in Table 1, “V / 1 min before heating” means that a predetermined AC voltage is applied between a conductor and a fixed wire at room temperature for 1 minute after being placed in a heating furnace. It is to measure whether the insulation state can be maintained when the voltage is applied. The term “heating during V / 30 minutes” means that a predetermined AC voltage is maintained between the conductor and the fixed line from the start of heating (0 minutes) to the end of heating (30 minutes) after being placed in a heating furnace. It is to measure whether or not the insulation state can be maintained when the voltage is applied. Further, "V / 1 minute after heating" means that the sample was placed in a heating furnace, heated, heated to 840 ° C. in 30 minutes, and immediately after the burner fire was extinguished,
It is to measure whether or not the insulation state can be maintained when a predetermined AC voltage is applied between the conductor and the fixed wire for one minute. Table 1
Among the test conditions in the dielectric breakdown voltage measurement test at
The term "after heating" refers to measuring a voltage value when the voltage is further increased after passing the dielectric strength measurement test and dielectric breakdown occurs. The standards in Table 1 refer to the fire resistance certification standards set and announced by the Fire Service Agency.

In Table 1, the insulation resistance of the refractory wire before heating is specified to be 50 MΩ or more in the standard. The insulation resistance value before the heating has characteristics exceeding the standard in both the embodiment and the conventional example. Generally, when an insulator is heated, insulation is deteriorated and insulation resistance is reduced. Therefore, the standard specifies that the insulation resistance after heating (when the furnace temperature reaches 840 ° C.) is 0.4 MΩ or more. The insulation resistance of the embodiment and the conventional example has characteristics exceeding the standard. But,
Comparing the example with the conventional example, the example shows that
It can be seen that the characteristics of the conventional example are 1.0 to 7.0 MΩ, which is much lower than that of the embodiment, whereas the conventional example has an impedance of Ω. In the dielectric strength test of the fire-resistant electric wire, a voltage is applied between the conductor of the sample and the fixed wire to increase the voltage, and a voltage value at the time of the dielectric breakdown is measured. The standard under the test condition "V / 1 min before heating" requires that no dielectric breakdown occurs when an AC voltage of 1500 V is applied for 1 minute between the conductor and the fixed wire at room temperature before heating is started. . In the dielectric strength test of “V / 1 minute before heating”, both the embodiment and the conventional example have standard characteristics. Test condition "Heating V / 30 minutes"
, It is required that from the start of heating (0 minutes) to the end of heating (30 minutes), insulation breakdown does not occur when an AC voltage of 600 V is continuously applied between the conductor and the fixed wire. . In the dielectric strength test of “V / 30 minutes during heating”, both the example and the conventional example have the standard characteristics. According to the standard of “V / 1 minute after heating”, the sample is placed in a heating furnace, heated, heated to 840 ° C. in 30 minutes to extinguish the fire of the burner, and immediately placed between the conductor and the fixed line.
It is required that a dielectric breakdown does not occur when an AC voltage of 00 V is applied for one minute. This “After heating V / 1
In the “dielectric strength test”, both the embodiment and the conventional example have standard characteristics.

The breakdown voltage of the refractory wire is not specified in the standard, but the breakdown voltage immediately after the furnace temperature is heated to 840 ° C. according to a predetermined standard is 1800 to 800. In contrast to 2500 V, the embodiment shows a much higher value of 3000 to 3500 V. That is, it can be seen that the example has a high dielectric breakdown voltage even when exposed to a high temperature, and that when used for a fire-resistant wire, the safety when exposed to a high temperature is higher than that of the conventional example. As is clear from the above characteristic tests of fire-resistant electric wires, both the examples and the conventional examples satisfy the fire resistance certification standards set by the Fire and Disaster Management Agency, but the insulation resistance when exposed to high temperatures, which is the most important fire-resistant electric wire. It can be seen that the embodiment is far superior to the conventional example in that the decrease in the dielectric breakdown voltage when exposed to a high temperature is small.

FIG. 7 shows another embodiment of the fireproof electric wire according to the present invention . In the drawing, the present embodiment is different from the embodiment shown in FIG. 1 in that the embodiment shown in FIG. 1 is a single-core wire, whereas the present embodiment is formed by twisting a large number of fireproof electric wires shown in FIG. This is a refractory wire composed of combined stranded wires. That is, reference numeral 20 denotes a stranded fire-resistant wire, and reference numeral 21 denotes a fire-resistant wire. The refractory wire 21 has a refractory layer 23 formed by winding a refractory tape 8 (10) shown in FIG. 1 around an outer periphery of a conductor 22 composed of copper. On this refractory layer 23, an insulator 24 is extruded and covered.
A plurality of the refractory wires 21 (3 in this embodiment)
This is wrapped with a twisted inclusion 25 and pressed into a substantially circular cross-section with a wrapping tape 26 to form it. The outermost layer is extruded and covered with a flame-retardant sheath 27 made of polyvinyl chloride resin or non-halogen polyethylene resin. Thus, the fire-resistant electric wire 20 is configured.

[0025]

According to the first aspect of the present invention, a composite fire-resistant tape in which a mica tape and a glass tape or a synthetic resin tape are bonded together on a conductor to form an integral unit is formed on the first winding part. The second winding part overlaps, and the third winding part is wound on the second winding part so as to overlap with a part of the first winding part. The "bullying" of the mica foil at the portion is eliminated, and it is possible to prevent the carbide from entering the refractory layer at the time of combustion, and it is possible to greatly improve the insulation resistance value and the withstand voltage value.

According to the second aspect of the present invention, a composite fire-resistant tape obtained by laminating a glass tape or a synthetic resin tape on the mica tape is integrated between the conductor and the insulator.
Since it is wound and interposed in a 1/2 to 1.3 / 2 overlap, "bullying" of the mica foil at the overlap portion at the time of winding is eliminated, and carbide is prevented from entering the refractory layer during combustion. As a result, the insulation resistance value and the withstand voltage value can be greatly improved.

[0027]

[Brief description of the drawings]

FIG. 1 is a diagram showing a state in which a fire-resistant tape is overlapped and wound around a conductor showing an embodiment of a fire-resistant wire according to the present invention .

FIG. 2 is a cross-sectional view of a fire-resistant electric wire in which a fire-resistant tape is wrapped around the conductor shown in FIG. 1;

FIG. 3 is a longitudinal sectional view of a fire-resistant electric wire in which a fire-resistant tape is wrapped around the conductor shown in FIG. 1;

FIG. 4 is a view showing a state in which a fire-resistant tape is overlapped and wound around a conductor showing an embodiment of the fire-resistant wire according to the present invention .

FIG. 5 is a cross-sectional view of a fire-resistant wire in which a fire-resistant tape is wrapped around the conductor shown in FIG. 4;

FIG. 6 is a longitudinal sectional view of a fire-resistant electric wire in which a fire-resistant tape is wrapped around the conductor shown in FIG. 4;

FIG. 7 is a view showing an embodiment of a fire-resistant wire obtained by twisting a plurality of fire-resistant wires according to the present invention .

FIG. 8 is a cross-sectional view showing a configuration of a conventional fire-resistant electric wire.

FIG. 9 is a view showing the structure of the conventional fire-resistant tape shown in FIG.

FIG. 10 is a view showing the structure of another conventional fire-resistant tape shown in FIG.

FIG. 11 is a view showing a state in which a fire-resistant tape of a conventional fire-resistant wire is overlapped and wound.

FIG. 12 is a cross-sectional view of a fire-resistant electric wire in which a fire-resistant tape is wrapped around the conductor shown in FIG. 11;

FIG. 13 is a longitudinal sectional view of a fire-resistant electric wire in which a fire-resistant tape is wrapped around the conductor shown in FIG. 11;

FIG. 14 is a view showing another lap winding state of a fire-resistant tape of a conventional fire-resistant electric wire.

FIG. 15 is a cross-sectional view of a fire-resistant electric wire in which a fire-resistant tape is wound around the conductor shown in FIG. 14;

FIG. 16 is a longitudinal sectional view of a fire-resistant electric wire in which a fire-resistant tape is wrapped around the conductor shown in FIG. 14;

[Explanation of symbols]

1,20 …………………………… Fireproof wire 2,22 …………………………… Conductors 3,23 ……………………… Fireproof layer 4,24 ………………………………… Insulator 5,17 …… …………………………………… Flame-retardant case 6 ……………………………………… Glass tape 7… ……………………………………………………………………………………………………………………… Fireproof tapes 8A, 10A …………………………………… 1
No. 8B, 10B .......................................
No. 8C, 10C ........................................
Rolled part 9 ……………………………………………………………………………………………………………………………………………… Crack 21 ………………………………………………………………………………………………………………… Inclusions 26 …………………………… Holding tape 27 …………………………………………………………………………………… Flame retardant sheath

Claims (2)

(57) [Claims] 1. A composite fire-resistant tape in which a mica tape and a glass tape or a synthetic resin tape are bonded together on a conductor to form an integrated fire-resistant tape, and a second winding part is overlapped on a first winding part. The third winding part is wound so as to overlap a part of the first winding part on the second winding part, and the insulator is extruded and coated on the wound composite refractory tape. A fire-resistant electric wire, characterized in that: 2. A composite fire-resistant tape obtained by laminating a glass tape or a synthetic resin tape on a laminated mica tape, and winding it between the conductor and the insulator in an overlapping ratio of 1.1 / 2 to 1.3 / 2. Fire-resistant electric wire characterized by being interposed.