JP2008159406A - Fire-resistant cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fire-resistant cable capable of delaying time during which a mica layer is exposed to high temperature at the time of disaster such as fire, and capable of improving on fire-resisting performance of the fire-resistant cable as a whole. <P>SOLUTION: The fire-resistant cable has a fire-resistant layer 3 formed by wrap-winding or putting longitudinally together a fire-resistant tape made by bonding a fire-resistant material made of mica powder or alumina powder to a synthetic resin film around the outer periphery of a conductor 2, and on the fire-resistant layer 3, an insulator layer 4 made of polyolefin based resin or a vinyl chloride based resin is formed, on which 4 furthermore, an under-layer sheath layer 5 structured by kneading a fire-resistant material used for the fire-resistant layer 3 into the polyolefin based resin or the vinyl chloride based resin is formed, and on the under-layer sheath layer 5, an upper-layer sheath layer 6 made of polyolefin based resin or vinyl chloride based resin is formed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a refractory cable, and in particular, when the cable is burned, it is difficult to transmit heat to the mica layer portion that is a refractory layer, and it is possible to maintain a stable refractory performance by delaying the time when the mica layer is detached and missing. Related to fireproof cable.

  In theaters and department stores where a large number of people gather, in order to safely guide people in the hall to the emergency exit in the event of a fire, etc. It is required to keep it on for a certain period of time. Therefore, the Japan Electrical Wire Manufacturers Association voluntarily established its own certification standards for fireproof cables, etc. for fireproof cables used for fire extinguishing equipment, alarm equipment, evacuation equipment wiring, etc. We are trying to ensure the quality of materials.

This fire-resistant cable is a cable that can supply power for a certain period of time even in the event of a fire, without causing the supply of power to stop due to a cable malfunction. is there.
The structure of such a refractory cable is configured by forming a refractory layer on the outer periphery of the conductor, forming an insulator on the refractory layer, and forming a sheath on the insulator (for example, (See Patent Document 1).

In addition, a conventional fireproof cable has a structure in which a fireproof tape is overlaid or vertically attached to a conductor as a fireproof layer to form a fireproof layer, on which an insulator coating, inclusions, presser winding tape, and sheath coating are applied. (For example, see Patent Document 2).
Utility model registration No. 2604827 (page 3 Fig. 4) JP2001-202833 (page 2 Fig. 1)

In this conventional fireproof cable, mica (a kind of mineral) is bonded to a polyethylene film or the like as a fireproof layer, and when the wire burns, the mica will eventually remain to maintain fireproof performance. It has become.
However, the mica layer that forms such a refractory layer has the property of being easily peeled off, and when the high temperature state by the flame continues for a long time, the mica layer gradually peels off and eventually affects the fire resistance performance. Has the problem. The mica layer forming the fireproof layer does not affect the fireproof performance as long as the mica layer does not peel off and is missing even when subjected to a flame.

  Therefore, in the case of a fireproof cable, the fireproof performance of the fireproof cable as a whole is not limited, in addition to satisfying the fireproof performance required for the fireproof cable, as long as the time during which the mica layer is exposed to a high temperature by the flame can be delayed. Performance can be improved.

  An object of the present invention is to provide a fireproof cable capable of delaying the time during which a mica layer is exposed to a high temperature state by a flame at the time of a disaster such as a fire and improving the fireproof performance of the entire fireproof cable. .

  In order to solve the above problems, the fireproof cable according to claim 1 is formed by wrapping or vertically attaching a fireproof tape in which a mica powder or an alumina powder fireproof material is bonded to a synthetic resin film on the outer periphery of a conductor to form a fireproof layer. And an insulating layer made of a polyolefin resin or a vinyl chloride resin is formed on the refractory layer, and the refractory layer used on the refractory layer is a polyolefin resin or a vinyl chloride resin on the insulator. A lower sheath layer constituted by kneading a material is formed, and an upper sheath layer made of a polyolefin resin or a vinyl chloride resin is formed on the lower sheath layer.

  According to the invention of claim 1 having such characteristics, it is possible to delay the time during which the mica layer is exposed to a high temperature state by a flame at the time of a disaster such as a fire, and to improve the fire resistance performance of the entire fire resistant cable. Can do.

  In order to solve the above-mentioned problem, the fireproof cable according to claim 2 forms a fireproof layer by wrapping or vertically attaching a fireproof tape in which a mica powder or an alumina powder fireproof material is bonded to the outer periphery of the conductor. Two or more refractory insulated wires formed by forming an insulator layer made of a polyolefin resin or a vinyl chloride resin on the refractory layer are twisted together, and the gap between the two or more refractory insulated wires is twisted. Interpose inclusions, twist two or more of the refractory insulated wires, wind the holding tape around the inclusion, and wrap the polyolefin resin or vinyl chloride resin on the holding tape. A lower sheath layer is formed by kneading a refractory material used for the refractory layer, and is formed of a polyolefin resin or a vinyl chloride resin on the lower sheath layer. It is constructed by forming a layer sheath layer.

  According to the invention of claim 2 having such a feature, it is possible to delay the time during which the mica layer is exposed to a high temperature state by a flame at the time of disaster such as a fire, and to improve the fire resistance performance of the entire fire resistant cable. Can do.

  In order to solve the above-mentioned problem, the fireproof cable according to claim 3 is the fireproof cable according to claim 1 or 2, wherein the fireproof tape is formed by collecting scaly soft mica on a polyolefin resin film. Is.

  According to the invention of claim 3 having such characteristics, it is possible to delay the time during which the mica layer is exposed to a high temperature state by a flame at the time of disaster such as a fire, and to improve the fire resistance performance of the entire fire resistant cable. Can do.

  In order to solve the above-described problem, the fireproof cable according to claim 4 is the fireproof cable according to claim 1, 2, or 3, wherein the fireproof material kneaded into the lower sheath layer is composed of soft natural laminated mica fragments. Is.

  According to the invention of claim 4 having such characteristics, it is possible to delay the time during which the mica layer is exposed to a high temperature state by a flame at the time of disaster such as a fire, and to improve the fire resistance performance of the entire fire resistant cable. Can do.

  In order to solve the above-mentioned problem, the fireproof cable according to claim 5 is the fireproof cable according to claim 1, 2, 3 or 4, wherein the lower sheath layer and the upper sheath layer are formed by two-layer coextrusion. It is what you do.

  According to the invention of claim 5 having such characteristics, it is possible to delay the time during which the mica layer is exposed to a high temperature state by a flame during a disaster such as a fire, and to improve the fire resistance performance of the entire fire resistant cable. Can do.

According to the present invention, it is possible to delay the time during which the mica layer is exposed to a high temperature state even when exposed to a flame at the time of cable combustion in a disaster such as a fire, and to improve the fire resistance performance of the entire fire resistant cable. it can. That is, according to the present invention,
Heat is not easily transmitted to the mica layer portion which is a fireproof layer, and the time for peeling and missing of the mica layer attached to the synthetic resin film can be delayed to maintain stable fireproof performance.

  Hereinafter, description will be given with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of the fireproof cable of the present invention, and FIG. 2 is a cross-sectional view of the fireproof cable shown in FIG.

  In FIG. 1, the fireproof cable 1 includes a conductor 2, a fireproof layer 3, an insulator layer 4, a lower sheath layer 5, and an upper sheath layer 6. That is, a refractory layer 3 made of a refractory tape is formed on the outer periphery of the conductor 2, and an insulator layer 4 is formed on the refractory layer 3. A lower sheath layer 5 is formed on the insulator layer 4, and an upper sheath layer 6 is formed on the lower sheath layer 5. Thus, the fireproof cable 1 in FIG. 1 is a case of a single core fireproof cable.

  The refractory layer 3 is formed of a refractory tape, and is configured by bonding a refractory material of mica powder or alumina powder to a synthetic resin film serving as a tape base material. As the fireproof tape, for example, there is a laminated mica tape in which fine soft natural laminated mica (phlogopite) pieces are collected and bonded together on a synthetic resin film to form a tape. This laminated mica tape includes a single-sided film laminated mica tape, a double-sided film laminated mica tape, and any of these. The laminated mica tape shown in FIG. 1 takes a single-sided film laminated mica tape as an example. This single-sided film assembled mica tape is configured by bonding a mica sheet to a polyethylene tape.

  The mica pieces of the soft natural laminated mica (phlogopite) of the laminated mica tape are formed in a scale shape, the thickness of one mica scale is 2 μm or less, and the particle size of the mica scale is less than 600 μm. It is good to do. The particle diameter of the mica scales of this soft natural laminated mica (phlogopite) is optimally composed of particularly 250 μm or less. Therefore, it is desirable that the maximum particle size of the mica scale particles is less than 600 μm.

  As shown in FIG. 1, the refractory layer 3 is wound on the conductor 2 by wrapping a refractory tape by 1/4 wrap, for example, 1 to 3 wraps (wrap wrap). Although not shown, the refractory layer 3 may be formed by wrapping, for example, 1 to 3 refractory tapes vertically. However, vertical attachment is advantageous because it is superior in workability compared to wrapping (horizontal winding), and scratches and cracks are unlikely to occur in the assembled mica tape during work. Therefore, in the present embodiment, a method is adopted in which the laminated mica tape is vertically attached to the outer periphery of the conductor 2 so that one end is overlapped with the other end.

  In this embodiment, the thickness of soft natural laminated mica (phlogopite) constituting the laminated mica tape is 0.09 to 0.15 mm, and the synthetic resin film (backing material) is polyethylene (PE), polypropylene. (PP) etc., and the thickness is 0.015 mm to 0.030 mm. This soft natural laminated mica (phlogopite) and a synthetic resin film (backing material) are bonded together to form a fireproof tape (fireproof layer 3).

  The insulator layer 4 is made of a polyolefin resin such as polyethylene or polypropylene, or a vinyl chloride resin such as vinyl chloride resin. This insulator layer 4 is extrusion-coated on the refractory layer 3 to form a refractory insulated core 10. Examples of the polyolefin resin constituting the insulator layer 4 include polyethylene (PE), ethylene vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), ethylene-α olefin copolymer, ethylene propylene. A copolymer etc. are mentioned. Each of these has characteristics, and can be used alone as a polyolefin-based resin or a plurality of types can be used in combination. For example, mechanical properties and difficulties can be obtained by using together polyethylene, which has good mechanical properties compared to EEA and EVA, but cannot add a large amount of flame retardant, and EEA and EVA, which can add a large amount of flame retardant. It becomes possible to constitute a material with good acceptability of the flame retardant.

  The lower sheath layer 5 is formed on the insulator layer 4 and is configured by kneading a refractory material used for the refractory layer 3 into a polyolefin resin or a vinyl chloride resin. This refractory material is mica powder or alumina powder. This mica powder is a mica piece of fine soft natural aggregate mica (phlogopite), is formed in a scale shape, the thickness of one mica scale is 2 μm or less, and the particle size of the mica scale is less than 600 μm It has been done.

Examples of the polyolefin resin used as the base of the lower sheath layer 5 include polyethylene (PE), ethylene vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), ethylene-α olefin copolymer, ethylene A propylene copolymer etc. are mentioned. Each of these has characteristics, and can be used alone as a polyolefin-based resin or a plurality of types can be used in combination. For example, mechanical properties and difficulties can be obtained by using together polyethylene, which has good mechanical properties compared to EEA and EVA, but cannot add a large amount of flame retardant, and EEA and EVA, which can add a large amount of flame retardant. It becomes possible to constitute a material with good acceptability of the flame retardant.
Examples of the vinyl chloride resin that serves as the base of the lower sheath layer 5 include vinyl chloride resin.

  The refractory material kneaded into the polyolefin-based resin or vinyl chloride-based resin that is the base material of the lower sheath layer 5 is made from soft natural laminated mica (phlogopite). Here, the fragments of the soft natural laminated mica (phlogopite) have a finer shape than the mica powder of the refractory material used for the fireproof layer 3 (mica pieces of soft natural laminated mica (phlogopite)). . That is, a fragment of soft natural assembled mica (phlogopite) is formed in a scale shape, the thickness of one mica scale is 2 μm or less, the particle size of the mica scale is less than 600 μm, and the fireproof layer 3 is formed. It has a smaller diameter than that used.

Further, the size of the fragments of the soft natural laminated mica (phlogopite) is not particularly limited, but it should be a size that does not cause any trouble when the lower sheath layer 5 is extrusion coated. It is.
The method for kneading the soft natural mica (phlogopite) fragments into the polyolefin resin or vinyl chloride resin, which is the base material of the lower sheath layer 5, is the same as that for adding a colorant to the sheath material. Can be used. That is, the method of kneading the fragments of soft natural laminated mica (phlogopite) is performed by charging and kneading the soft natural laminated mica (phlogopite) in the same manner as the usual colorant addition.

The upper sheath layer 6 is formed on the lower sheath layer 5 and is made of polyolefin resin or vinyl chloride resin.
Polyolefin resins constituting the upper sheath layer 6 include polyethylene (PE), ethylene vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), ethylene-α olefin copolymer, ethylene propylene. A copolymer etc. are mentioned. Each of these has characteristics, and can be used alone as a polyolefin-based resin or a plurality of types can be used in combination. For example, mechanical properties and difficulties can be obtained by using together polyethylene, which has good mechanical properties compared to EEA and EVA, but cannot add a large amount of flame retardant, and EEA and EVA, which can add a large amount of flame retardant. It becomes possible to constitute a material with good acceptability of the flame retardant.
Examples of the vinyl chloride resin that serves as the base of the upper sheath layer 6 include vinyl chloride resin.

  Regarding the sheath material used as the base of the lower sheath layer 5 and the sheath material used as the base of the upper sheath layer 6, the standard shape includes a rubber mixture, but generally, a polyolefin resin or a vinyl chloride resin is used. It is used. Recently, polyolefin resins (for example, polyethylene) have been used because of restrictions on harmful gases generated during combustion.

The lower sheath layer 5 and the upper sheath layer 6 may be formed on the insulator layer 4 by two-layer coextrusion. That is, the refractory cable 1 shown in FIG. 1 is formed by extruding the sheath into two layers, and covering the lower sheath layer 5 as a lower layer with a polyethylene material in which mica fragments used in the refractory layer are kneaded. .
As described above, the fireproof cable 1 shown in FIG. 1 kneads mica fragments (soft natural laminated mica (phlogopite) fragments) into the lower sheath layer 5 which is the lower layer of the sheath, so that the fireproof cable 1 is fired or the like. Even if it is exposed to a flame and burned, the mica kneaded into the lower sheath layer 5 does not burn, so the ignition time of the entire sheath composed of the upper and lower layers is delayed as a whole (it becomes difficult to ignite).

The thickness of the lower sheath layer 5, which is the lower layer of the sheath, affects the characteristics of the entire sheath when the ratio of the lower sheath layer 5 is large compared to the upper sheath layer 6. A thickness of 0.5 mm is desirable.
In the case of a sheath constituting a cable, when performing a tensile test (physical property test) of the sheath, the uneven surface generated in the sheath must be eliminated and smoothed. In addition, if mica fragments (soft natural aggregate mica (phlogopite) fragments) are kneaded, mechanical strength is not expected. Therefore, considering the safety of physical properties, mica fragments (soft natural It is necessary to leave at least 1 mm of the upper sheath layer 6 that does not knead the aggregate mica (debris of phlogopite).
Moreover, since the ratio of the mica fragments kneaded into the lower sheath layer 5 that is the lower layer of the sheath may not be uniformly coated when the refractory cable 1 is manufactured when there are many mica fragments kneaded into the lower sheath layer 5, Desirably, the mica fragments are about 10% by weight with respect to about 90% by weight of the polyethylene material as the base of the sheath layer 5.

Usually, since the sheath material uses flame-resistant polyethylene or vinyl chloride, it has a structure that is excellent in flame resistance and difficult to ignite, but the fire-resistant cable 1 shown in FIG. 1 further improves the flame resistance. The ignition time is delayed.
Therefore, in the refractory cable 1 shown in FIG. 1, the high temperature when exposed to the flame is not easily transmitted to the mica layer of the refractory tape (the refractory layer 3) under the insulator layer 4, and the time for reaching the high temperature state is reached. Can be delayed, and the time in a high temperature state can be delayed. For this reason, the mica layer on the conductor that affects the fire resistance performance is not peeled off or lost, and the shape of the mica layer can be maintained longer than usual.

FIG. 3 shows another embodiment of the fireproof cable according to the present invention.
The fireproof cable in FIG. 3 is a case of a multi-core fireproof cable (three-core cable in FIG. 3).
In FIG. 3, the fireproof cable 20 includes a conductor 2, a fireproof layer 3, a fireproof insulating core 10 composed of the insulator layer 4, and two or more fireproof insulating cores 10 intervening in a gap. 21, presser winding tape 22, lower sheath layer 5, and upper sheath layer 6. That is, a refractory layer 3 composed of a refractory tape is formed on the outer periphery of the conductor 2, and an insulator layer 4 is formed on the refractory layer 3 to form a refractory insulation core 10. Yes. Three refractory insulation cores 10 are twisted together, and inclusions 21 are interposed between the refractory insulation cores 10 so that the refractory cable 20 has a substantially circular cross section. ing.
A lower sheath layer 5 is formed on the presser winding tape 22, and an upper sheath layer 6 is formed on the lower sheath layer 5. Thus, the fireproof cable 20 in FIG. 3 is a case of a multi-core fireproof cable.

The refractory layer 3 and the insulator layer 4 are the same as the refractory layer 3 and the insulator layer 4 of the refractory cable 1 shown in FIG.
In addition, the inclusions 21 are provided so that the fireproof cable 20 has a substantially circular cross section along with the fireproof insulating cores 10 when the three fireproof insulating cores 10 are twisted together. As the inclusion 21, paper, jute, PP defibrated yarn, or the like is generally used.

  As the press-wound tape 22 in which three fire-resistant insulated cores 10 are twisted and wound around the outer periphery with inclusions 21 interposed between the fire-resistant insulated cores 10, polyester nonwoven fabric, nylon nonwoven fabric, polypropylene, polyester tape, Glass tape, paper tape, ceramic paper, etc. are used.

A lower sheath layer 5 formed by kneading a refractory material used for the refractory layer into a polyolefin-based resin or a vinyl chloride-based resin is coated on the press-wound tape 22. The lower sheath layer 5 is the same as the lower sheath layer 5 of the fireproof cable 1 shown in FIG.
Furthermore, an upper sheath layer 6 made of polyolefin resin or vinyl chloride resin is coated on the lower sheath layer 5. This upper sheath layer 6 is the same as the upper sheath layer 6 of the fireproof cable 1 shown in FIG.

It is a perspective view which shows embodiment of the single core fireproof cable of this invention. It is sectional drawing of the fireproof cable shown in FIG. It is a perspective view which shows embodiment of the multi-core fireproof cable of this invention.

Explanation of symbols

1,20 …………………… Fireproof cable 2 …………………………… Conductor 3 ……………………………… Fireproof layer 4 ……………………… …… Insulator layer 5 ……………………………… Lower sheath layer 6 …………………………… Upper sheath layer 10 ………………………… Fireproof insulation core 21 ………………………… Inclusion 22 ………………………… Press-wrapping tape

Claims (5)

A refractory layer is formed by wrapping or vertically attaching a refractory tape in which a mica powder or alumina powder refractory material is bonded to a synthetic resin film on the outer periphery of the conductor.
Forming an insulator layer made of polyolefin resin or vinyl chloride resin on the fireproof layer;
On the insulator layer, a lower sheath layer formed by kneading a refractory material used for the refractory layer into a polyolefin resin or vinyl chloride resin is formed,
A fireproof cable in which an upper sheath layer made of a polyolefin resin or a vinyl chloride resin is formed on the lower sheath layer. A refractory layer is formed by wrapping or vertically attaching a refractory tape in which a mica powder or alumina powder refractory material is bonded to a synthetic resin film on the outer periphery of the conductor.
Two or more refractory insulation cores formed by forming an insulator layer made of polyolefin resin or vinyl chloride resin on the refractory layer are twisted together, and the gap between the two or more refractory insulation cores twisted together is laid. Intervening,
Twist two or more of the refractory insulation cores, press the outer periphery with the inclusions interposed therebetween,
Forming a lower sheath layer formed by kneading a refractory material used for the refractory layer into a polyolefin resin or vinyl chloride resin on the press-wrapping tape;
A fireproof cable in which an upper sheath layer made of a polyolefin resin or a vinyl chloride resin is formed on the lower sheath layer. The fireproof tape is
The fireproof cable according to claim 1 or 2, wherein a scaly soft mica is assembled on a polyolefin resin film. The refractory material kneaded into the lower sheath layer is:
The fireproof cable according to claim 1, 2, or 3, which is a fragment of soft natural laminated mica. The lower sheath layer and the upper sheath layer are:
The fireproof cable according to claim 1, 2, 3 or 4, which is formed by two-layer coextrusion.

Images