JP5363963B2 - Fireproof design of protective sheet for communication cable - Google Patents

Description

  The present invention relates to a fireproof design of a protection sheet for a communication cable, and more specifically, impregnating a cotton fabric layer with a flame retardant material and forming a flame retardant layer on the surface thereof, thereby providing fire resistance, heat resistance, and fire spread. The present invention relates to a protective sheet for a communication cable, the method of manufacturing the same, and a communication cable with the protective sheet.

  A communication cable composed of an optical fiber cable, a metal cable, or the like is wired to a subscriber's house via, for example, a so-called “to-do” (cable tunnel) installed underground from a telephone station.

  For this reason, when a fire breaks out along the road, the damage is so great that the communication cable installed in the road is wrapped around a protective sheet to prevent the spread of fire and maintain the communication state. In general, the attached communication cable is supported by a plurality of cable brackets installed at regular intervals along the length of the path.

  As such a protective sheet for a communication cable, for example, a cover sheet (Patent Document 1) having a metal foil and a reinforcing cloth on both sides of a heat insulating layer, a non-combustible heat insulating material, a woven cloth made of carbon fiber and metal fiber, A disaster prevention sheet (Patent Document 2) formed from a composite woven fabric laminated with an aluminum foil is known.

Japanese Utility Model Publication No. 61-162236 JP-A-62-221375

  However, it can be said that the protective sheets disclosed in Patent Documents 1 and 2 have appropriate fire resistance in order to protect them from fire, but other characteristics, particularly water resistance, are improved. There was room for.

  That is, on the road, it is actually possible that the water that has penetrated the ground dripped from the ceiling and this water contacts the protective sheet. In this case, since the protective sheet disclosed in Patent Documents 1 and 2 does not have sufficient water resistance, the water is absorbed by the protective sheet, the weight of the protective sheet increases, and the protective sheet is bent. The communication cable may be bent. If this bending becomes excessive due to the absorption of water over a long period of time, there is a possibility that the transmission characteristics of the communication cable are deteriorated. Furthermore, it has been reported that the environmental atmosphere in Todo is about “room temperature 25 ° C., humidity 70%” throughout the year, and it is desired to take measures against mold generation.

  In order to solve such a problem, the applicants of the present application have already filed Japanese Patent Application No. 2009-58655 (unpublished at the time of filing of the present application), and in particular, protection for communication cables excellent in water resistance. Proposing seats.

  However, in the development of protective sheets for communication cables, the technical pursuit of excellent fire resistance, heat resistance, and fire spread prevention is endless, and rather it does not increase the total weight of the sheet, but rather it is lighter. Therefore, there is a demand for the development of a novel protective sheet for communication cables that is excellent in fire resistance, heat resistance and fire spread prevention. In addition, although the usage is limited, there is a demand for the development of a new protective sheet for communication cables that can achieve an effect specific to preventing fire spread while further reducing the weight of the sheet and reducing the product cost. Furthermore, although it is an incidental element, countermeasures against mold generation are also desired.

  The present invention was devised under such circumstances, and its purpose is to significantly improve fire resistance, heat resistance and fire spread prevention, and to reduce the weight of the sheet. It is to provide a protective sheet for a new communication cable. It is another object of the present invention to provide a novel protective sheet for a communication cable that can obtain a special effect for preventing fire spread while reducing the weight of the sheet and reducing the product cost. In addition, countermeasures against mold generation will be taken as necessary.

  In order to solve such a problem, the present invention is a protective sheet for a communication cable having a heat insulating layer and a sheet main body provided with a laminated body on both sides of the heat insulating layer, The cotton cloth layer, comprising: a ventilation barrier layer disposed on the heat insulating layer and including a metal layer; a cotton fabric layer disposed on the ventilation barrier layer; and a flame retardant layer disposed on the cotton fabric layer. Is configured to be impregnated with a flame retardant material throughout the entire layer.

  The present invention provides a pair of laminates having a gas barrier layer including a metal layer, a cotton fabric layer disposed on the gas barrier layer, and a flame retardant layer disposed on the cotton layer, A protective sheet for a communication cable in which ventilation blocking layers are joined to each other, and the cotton cloth layer is configured to be impregnated with a flame retardant material throughout the entire layer.

  Moreover, as a preferable aspect of the protective sheet for a communication cable of the present invention, the heat insulating layer is configured to be one type selected from the group of carbon fiber, metal fiber, ceramic fiber, and acrylic fiber.

  Further, as a preferred embodiment of the communication cable protective sheet of the present invention, the flame retardant material impregnated in the cotton fabric layer is selected from the group consisting of silicone rubber, chloroprene rubber, fluororubber, EPDM, NBR, and hydrogenated styrene thermoplastic elastomer. It is comprised so that it may consist of 1 type selected.

  Moreover, as a preferable aspect of the protective sheet for a communication cable of the present invention, the ventilation blocking layer includes a laminated structure of a metal layer and a resin layer.

  As a preferred embodiment of the communication cable protective sheet of the present invention, the flame retardant layer is selected from the group consisting of silicone rubber, chloroprene rubber, fluororubber, EPDM, NBR, and hydrogenated styrene thermoplastic elastomer. Consists of a layer containing the main component.

  Moreover, as a preferable aspect of the protective sheet for a communication cable of the present invention, the cotton fabric layer and / or the flame retardant layer is configured to contain a fungicide.

  A method for producing a protection sheet for a communication cable as described above, wherein the method comprises impregnating a flame retardant material over the entire area of the cotton fabric layer, and laminating the flame retardant layer on the cotton fabric layer. And a step of forming.

  As a preferred embodiment of the method for producing a protective sheet for a communication cable of the present invention, the flame retardant material is selected from the group consisting of silicone rubber, chloroprene rubber, fluororubber, EPDM, NBR, and hydrogenated styrene thermoplastic elastomer. The flame retardant layer is a kind selected from the group consisting of silicone rubber, chloroprene rubber, fluoro rubber, EPDM, NBR, and hydrogenated styrenic thermoplastic elastomer, and the cotton layer after the impregnation step After that, a flame retardant layer is applied to the surface layer of the cotton cloth layer, and then the coating film is dried. Thereafter, the polymer is crosslinked and polymerized as necessary.

  The communication cable with a protective sheet of the present invention is configured by winding the above-described communication cable protective sheet around the communication cable.

  The present invention is a communication cable protective sheet having a heat insulating layer and a sheet body having a laminate on both sides of the heat insulating layer, the laminate being disposed on the heat insulating layer and including a metal layer. There is a ventilation barrier layer, a cotton fabric layer disposed on the ventilation barrier layer, and a flame retardant layer disposed on the cotton fabric layer, and the cotton fabric layer has a flame retardant material over the entire region. Therefore, it is possible to obtain a communication cable protection sheet with significantly improved fire resistance and heat resistance. Moreover, even when the same fire resistance and heat resistance effects are obtained, by adopting a combination configuration of a cotton fabric layer impregnated with a flame retardant material and a flame retardant layer formed thereon, the flame retardant is adopted. The amount of material used can be reduced, and the weight of the sheet can be reduced. Furthermore, the product cost can be reduced.

  Moreover, the communication cable protective sheet comprising a pair of laminates and omitting the heat insulating layer can obtain an effect specialized in preventing fire spread while further reducing the weight of the sheet and reducing the product cost.

FIG. 1 is a plan view showing a preferred embodiment of a communication cable protection sheet according to the present invention. FIG. 2 is a sectional view taken along line II-II in FIG. FIG. 3 is a front view showing a preferred embodiment of a communication cable with a protective sheet according to the present invention. FIG. 4 is a drawing showing a step of the method for manufacturing a communication cable protection sheet according to the present invention. FIG. 5: is a top view which shows the other process of the manufacturing method of the protection sheet for communication cables which concerns on this invention. FIG. 6 is a drawing schematically showing a method of stacking in the vicinity of the end of the communication cable protection sheet according to the present invention.

Hereinafter, preferred embodiments for carrying out the present invention will be described in detail.
[Description of protective sheet for communication cable]
FIG. 1 is a plan view showing a preferred embodiment of a protective sheet for a communication cable according to the present invention, FIG. 2 is a sectional view taken along line II-II in FIG. 1, and FIG. It is a front view which shows suitable one Embodiment of the communication cable with a protection sheet which concerns on this invention.

  As shown in FIG. 1, the communication cable protection sheet 100 of the present invention (hereinafter sometimes simply referred to as “protection sheet 100”) is provided on the sheet main body 10 and one surface 10 a of the sheet main body 10. And two sheet fasteners 14 that are fastened in a state where the sheet body 10 is wound.

  The sheet fastener 14 includes, for example, a flame resistant belt 12 that is fixed to one surface 10 a of the seat body 10, and a metal fitting 13 that is attached to one end of the belt 12. The metal fitting 13 can hold the sheet body 10 in a wound state, for example, by hooking and pulling out the other end of the belt 12.

  As shown in the cross-sectional view of FIG. 2, the sheet main body 10 includes a heat insulating layer 1 and laminates 8 provided on both surfaces of the heat insulating layer 1.

  As shown in the figure, the laminate 8 is a laminate comprising a ventilation barrier layer 2 composed of a resin layer 3 and a metal layer 4, and a cotton fabric layer 5 and a flame retardant layer 6 disposed on the ventilation barrier layer 2. A sheet 7 is provided.

  The ventilation blocking layer 2 is a layer for blocking ventilation, and prevents the flame from reaching the communication cable even in the event of a fire.

  The flame retardant layer 6 is disposed on the cotton fabric layer 5 while being bonded. Further, the cotton fabric layer 5 is disposed on the ventilation blocking layer 2 in a non-adhered state. And the laminated body 8, the heat insulation layer 1, and the laminated body 8 are integrated and comprised by sewing using the thread | yarn 11 for sewing.

  The cotton fabric layer 5 in the present invention is characterized in that it is constituted by impregnating a flame retardant material over the entire area of the layer, which will be described in detail later.

  As shown in FIG. 3, in the protective sheet 100 according to the present invention, first, the sheet body 10 is wound around the communication cable C, and the other end of the belt 12 is hooked and pulled out to the metal fitting 13 attached to one end of the belt 12. Thus, the wound sheet body 10 is configured to be fastened.

  The communication cable 200 with the protective sheet formed in this way is installed in a state where it is placed on the cable bracket 30 that is installed at regular intervals along the length direction of the road. The Here, the cable bracket 30 is, for example, a rod-like member provided so as to protrude from the wall surface of the path.

  The protective sheet 100 according to the present invention includes a heat insulating layer 1 in the center, and includes a flame retardant layer 6 and a cotton fabric layer 5 impregnated with a flame retardant material on the outside. For this reason, the protective sheet 100 is sufficiently wound around the communication cable C, for example, even if the outside of the protective sheet becomes high temperature due to the occurrence of a fire, sufficiently preventing the communication cable C from reaching a high temperature state. Can do. In the present invention, the combination of the flame retardant layer 6 and the cotton fabric layer 5 impregnated with a flame retardant material can increase the efficiency of fire resistance, heat resistance, and fire spread prevention, and reduce the weight of the sheet. It becomes possible. For this, refer to a specific experimental example described later.

  Furthermore, since the protective sheet 100 also has the ventilation blocking layer 2, it is possible to sufficiently prevent the flame from reaching the communication cable C even in the event of a fire.

  Furthermore, especially the laminated body 8 is excellent in the water resistance of the protective sheet 100. For this reason, even if water that has penetrated the ground dripped from the ceiling and contacts the outside of the protective sheet 100, the laminated body 8 sufficiently prevents water absorption. Moreover, even if water contacts the laminated body 8 inside the protective sheet 100, the laminated body 8 sufficiently prevents water from being absorbed. For this reason, the increase in the weight of the protective sheet 100 is sufficiently suppressed, and the bending of the protective sheet 100, in particular, the bending of the portion of the protective sheet 100 that is not supported by the cable bracket 30 is sufficiently suppressed. As a result, the bending of the communication cable C is sufficiently suppressed. Therefore, the protective sheet 100 can suppress a decrease in transmission characteristics in the communication cable C.

  Further, the protective sheet 100 has practically sufficient shearing properties and wear resistance. Therefore, even if an operator steps on the protective sheet 100 by mistake or the bending of the protective sheet 100 becomes excessive, the protective sheet 100 is difficult to tear due to the shearing force applied to the protective sheet 100 at that time. Further, even in an environment where the protective sheets 100 are rubbed with each other during the cable laying operation or after the cable laying, holes or the like are hardly generated due to the frictional force.

  In the protective sheet 100 of the present invention, the cotton fabric layer 5 is disposed on the ventilation barrier layer 2 in a non-adhered state (non-adhered). Therefore, the flexibility of the protective sheet 100 is increased as compared with the case where the cotton fabric layer 5 is bonded onto the ventilation blocking layer 2. For this reason, the operation | work at the time of winding the protection sheet 100 around the communication cable C becomes easy.

  Next, the heat insulating layer 1, the ventilation blocking layer 2, the cotton fabric layer 5, and the flame retardant layer 6 constituting the sheet body 10 in the present invention will be described in more detail individually.

( Description of heat insulation layer 1 )
As long as the material which comprises the heat insulation layer 1 is a material which has heat insulation, what kind of thing may be sufficient as it. From the viewpoint of protecting the communication cable C from high heat at the time of fire, it is preferably a flame retardant.

  As the flame retardant, for example, carbon fiber, metal fiber, ceramic fiber such as alumina fiber, acrylic fiber, or the like can be used. Among these, it is particularly preferable to use a flexible acrylic fiber having excellent flame resistance. As an example of a specific acrylic fiber, for example, Pyromex (registered trademark) felt # 300HS is preferably used.

  Carbon fibers, metal fibers, and acrylic fibers have flexibility. For this reason, when carbon fiber, metal fiber, or acrylic fiber is used as the material constituting the heat insulating layer 1, there is no damage due to load or scattering of the material unlike conventional ceramic materials, and safety is ensured. There is a merit that it becomes higher.

  The thickness of the heat insulating layer 1 is not particularly limited, but is particularly 2.0 to 10.0 mm from the viewpoint of protecting the flexibility of the protective sheet 100 and protecting the communication cable C from fire. Preferably there is.

( Description of ventilation block 2 )
As described above, the ventilation blocking layer 2 includes the metal layer 4, and preferably includes, for example, a resin layer 3 and a metal layer 4. The resin constituting the resin layer 3 is not particularly limited as long as it is a resin. Specific preferred examples include polyethylene terephthalate (PET), nylon, and polyimide. In particular, polyethylene terephthalate is preferable from the viewpoint of high strength and flexibility.

  Examples of the metal layer 4 include aluminum foil, stainless steel foil, and copper foil. Among these, aluminum foil is preferably used from the viewpoints of weight reduction and thermal conductivity. The thickness of the metal layer 4 is preferably about 0.01 to 0.20 mm. More preferably, it is 0.03-0.06 mm.

  Such a ventilation blocking layer 2 may be integrated by laminating and adhering the resin layer 3 on the metal layer 4 by extrusion coating or the like.

( Description of cotton layer 5 )
The cotton fabric layer 5 of the present invention has a structure in which a flame retardant material is impregnated over the entire area of the layer.
That is, it is comprised from the part which consists of cotton cloth, and the flame retardant material impregnated in the clearance gap between cotton cloth.

  In the present invention, “a structure in which a flame retardant material is impregnated throughout the entire area of the layer” refers to a structure in which a uniform flame retardant material exists in the thickness direction of a cotton cloth. The use of such expressions is intended to exclude the case where flame retardant materials exist only in the vicinity of the surface layer of the cotton cloth, and based on such a purpose, “a structure in which a uniform flame retardant material exists” is interpreted. do it.

  Specifically, in order to make a structure impregnated with a flame retardant material according to the present invention, for example, a cotton cloth is immersed in a solution for impregnation in which a flame retardant material is dissolved in a solvent (dipping: so-called soaking). After that, the cotton cloth is squeezed and dried. Or you may make it spray coat the solvent which dissolved the flame-retardant material from the both surfaces side of the cotton cloth. However, in these methods, it is necessary to adjust the viscosity of the impregnation solution in which the flame retardant material is dissolved in a solvent so that the uniform flame retardant material exists in the thickness direction of the cotton cloth. In general, the viscosity is adjusted to be low so that the penetration becomes easy.

  As the flame retardant material to be impregnated, silicone rubber, chloroprene rubber, fluoro rubber, EPDM, NBR, hydrogenated styrene thermoplastic elastomer (SEPS, SEBS, etc.) and the like are preferably used. Of these, silicone rubber, EPDM, NBR, SEPS, and SEBS are preferably used from the viewpoint of halogen-free. Furthermore, it is more desirable to use silicone rubber from the viewpoint of heat resistance.

  The amount of impregnation of the flame retardant material in the cotton fabric layer 5 is determined by the porosity of the cotton fabric, the content concentration of the flame retardant material in the solvent used for impregnation.

By impregnating the cotton fabric layer 5 with a flame retardant material such as silicone rubber, the fire resistance of the cotton fabric layer 5 that can function as a skeleton of the fire resistant layer is improved. As a result, fire resistance is remarkably improved by a combination with a flame retardant layer 6 (for example, composed of silicone rubber) described later. This combination effect of the present invention is also apparent from experimental examples to be described later. For example, on the assumption that the total amount of silicone rubber used is the same, the cotton fabric layer 5 is not impregnated with a flame retardant material such as silicone rubber, but only a flame retardant layer 6 (for example, composed of silicone rubber). It has been confirmed that the fire resistance effect of the present invention is much higher than that of the configuration in which the thickness is increased.
The thickness of the cotton fabric layer 5 is not particularly limited, but is usually about 0.1 to 0.5 mm. The thickness is more preferably 0.2 to 0.4 mm from the viewpoint of strength and weight reduction.

  When impregnating the cotton fabric layer 5 with a flame retardant material, it is desirable to contain a fungicide at the same time. For example, when a silicone rubber (millable type) is used as the flame retardant material, a rubber coating composition using a sulfur compound type antifungal agent as the antifungal agent and an acyl organic peroxide as the crosslinking agent is used. Is good. As a crosslinking method, for example, a continuous hot air crosslinking method may be used.

( Description of flame retardant layer 6 )
The material which comprises the flame-resistant layer 6 should just be a material which has a flame retardance. As such a flame retardant material, silicone rubber, chloroprene rubber, fluoro rubber, EPDM, NBR, hydrogenated styrene thermoplastic elastomer (SEPS, SEBS, etc.) and the like are preferably used. Of these, silicone rubber, EPDM, NBR, SEPS, and SEBS are preferably used from the viewpoint of halogen-free. Furthermore, it is more desirable to use silicone rubber from the viewpoint of heat resistance.

  The thickness of the flame retardant layer 6 is not particularly limited, but is usually 0.03 to 0.30 mm. From the viewpoint of fire resistance and weight reduction, it is preferably 0.03 to 0.10 mm.

  Such a flame retardant layer 6 is formed, for example, by coating a solution obtained by dissolving the above flame retardant material in a solvent on the cotton fabric layer 5.

  In addition, like the said cotton cloth layer 5, it is desirable to make the flame-retardant layer 6 contain a fungicide. For example, when silicone rubber (millable type) is used as the main component constituting the flame retardant layer 6, a sulfur compound type antifungal agent is used as the antifungal agent, and an acyl organic peroxide is used as the crosslinking agent. A rubber coating composition may be used. As a crosslinking method, for example, a continuous hot air crosslinking method may be used.

[Method of manufacturing protective sheet for communication cable]
A method for manufacturing a communication cable protection sheet having the above-described configuration will be described with reference to FIGS. 4 and 5.

  FIG. 4 is a drawing showing one step of a method for manufacturing a communication cable protection sheet according to the present invention, and FIG. 5 is a drawing showing another step of the method for manufacturing a communication cable protection sheet according to the present invention. .

  Laminated bodies 8 are formed on both surfaces of the heat insulating layer 1 to form a sheet body 10.

  For this purpose, as shown in FIG. 4, one heat insulating layer 1, two air blocking layers 2, and two laminated sheets 7 are prepared in advance.

  The ventilation blocking layer 2 is preferably composed of a laminate of a resin layer 3 and a metal layer 4. Such a ventilation blocking layer 2 is prepared by, for example, integrating the resin layer 3 on the metal layer 4 by extruding and adhering the resin layer 3 by extrusion coating or the like.

  The laminated sheet 7 is formed by laminating the flame retardant layer 6 on the surface of the cotton fabric layer 5 impregnated with the flame retardant material. For example, when the flame retardant material impregnated in the cotton fabric layer 5 is composed of silicone rubber and the main component constituting the flame retardant layer 6 is composed of silicone rubber, first, the cotton fabric prepared first is impregnated with silicone rubber. . For that purpose, for example, a vulcanizing agent, a crosslinking agent, a fungicide, etc. are added to a silicone compound as a raw material for the silicone rubber, and the viscosity is adjusted with a solvent, and then a solution for impregnation is prepared. The cotton cloth is dipped in, and then the cotton cloth is squeezed and dried. Next, on the cotton fabric layer 5 thus formed, for example, a vulcanizing agent, a crosslinking agent, an antifungal agent, etc. are added to a silicone compound as a raw material of the silicone rubber, and the viscosity is adjusted with a solvent, and defoaming is performed. After the silicone paste is obtained, the silicone paste is applied to the surface of the cotton fabric layer 5 and dried to form the flame retardant layer 6, and then heated to impregnate the silicone rubber impregnated in the cotton fabric layer 5 and The silicone rubber constituting the fuel layer 6 is crosslinked and polymerized.

  Next, the air blocking layer 2 and the laminated sheet 7 are overlapped so that the air blocking layer 2 and the laminated sheet 7 are sequentially disposed on both sides of the heat insulating layer 1, respectively. That is, the laminated sheet 7, the ventilation blocking layer 2, the heat insulating layer 1, the ventilation blocking layer 2, and the laminated sheet 7 are overlapped in this order.

  Next, as shown in FIG. 5, the laminated sheet 7, the ventilation barrier layer 2, the heat insulating layer 1, the ventilation barrier layer 2, and the laminated sheet 7 are integrated by sewing using a sewing thread 11. In this way, the sheet body 10 can be obtained. When sewing using the sewing thread 11, the end of the laminated sheet 7 and the air blocking layer 2 positioned above and the end of the laminated sheet 7 and the air blocking layer 2 positioned below are usually, for example, As shown in FIG. 6, the heat insulating layer 1 is folded on one side 1 a, and the folded portion is sewn using a sewing thread 11.

  Two sheet fasteners 14 are prepared for the sheet body 10 thus obtained, and the belt 12 of the sheet fastener 14 is attached to the one surface 10 a side of the sheet body 10, for example, a thread similar to the thread 11. Install by sewing using. In this way, the manufacture of the protective sheet 100 is completed.

[Description of communication cable 200 with protective sheet]
As shown in FIG. 3, the communication cable 200 with the protective sheet is configured by winding the sheet body 10 of the protective sheet 100 around the communication cable C and fastening the sheet body 10 with the sheet fastener 14 in a state where the sheet body 10 is wound. .

[Description of Modifications of the Present Invention]
The present invention is not limited to the above embodiment. For example, in the above embodiment, the cotton fabric layer 5 is disposed on the ventilation barrier layer 2 in a non-adhered state. However, the cotton fabric layer 5 may be disposed on the ventilation barrier layer 2 in an adhesive state.

  Moreover, the communication cable C is not specifically limited, For example, any may be an optical fiber, a metal cable, etc.

  Moreover, in the said embodiment, although the sheet | seat fastener 14 is fixed to the one surface 10a side of the sheet | seat main body 10, and is integrated with the sheet | seat main body 10, it can also be comprised as a different body from a sheet | seat main body. In this case, the protective sheet 100 is composed only of the sheet body 10. Even in this case, the sheet body 10 can be fastened by winding and tying a string-like member having flame resistance.

  Furthermore, in the said embodiment, although the ventilation block 2 is comprised by the laminated body of the resin layer 3 and the metal layer 4, the resin layer 3 does not need to be. In this case, the ventilation blocking layer 2 is composed only of the metal layer 4.

  Moreover, the most important thing in the modified example of the present invention is a sheet in which the heat insulating layer 1 is omitted if the purpose is to prevent the spread of fire only (in order to prevent the spread of fire, the self-extinguishing property of the sheet body is required). The configuration of the main body 10 is also an embodiment that can be implemented. In this case, it becomes the structure of the sheet | seat main body 10 which excluded the heat insulation layer 1 from the structure of embodiment shown by FIGS. That is, the sheet body 10 is configured by stacking the laminated sheet 7, the ventilation blocking layer 2, the ventilation blocking layer 2 and the laminated sheet 7 in this order. The laminated sheet 7 and the ventilation blocking layer 2 have the same configuration as that described above.

  Hereinafter, the present invention will be described in more detail with reference to specific examples.

[Example 1]
( Production of Example 1 sample )
A sample of Example 1 of the sheet main body 10 which is the main body portion of the protective sheet for a communication cable of the present invention was produced in the following manner.

  First, a heat insulating layer, a ventilation blocking layer, and a laminated sheet (a flame retardant layer / a cotton cloth layer) were prepared as follows.

  As the heat insulation layer 1, felt-like acrylic fibers (manufactured by Toho Tenax Co., Ltd .; Pyromex felt # 300HS) were prepared.

  As the ventilation blocking layer 2, a laminate of the resin layer 3 and the metal layer 4, that is, a laminate of a PET film having a thickness of 12 μm and an aluminum foil having a thickness of 30 μm was prepared.

  As the laminated sheet 7, a laminated sheet 7 of a cotton cloth layer 5 impregnated with silicone rubber and a flame retardant layer 6 made of silicone rubber formed thereon was prepared. The specific manufacturing method of the laminated sheet 7 is as follows. That is, a vulcanizing agent, a crosslinking agent, and an antifungal agent were added to a silicone compound as a raw material for the silicone rubber, dissolved in a toluene solvent, and the viscosity was adjusted. A cotton cloth having a thickness of 320 μm was dipped in the silicone rubber impregnation solution, and then the cotton cloth was squeezed and dried.

  Next, a vulcanizing agent, a crosslinking agent, and an antifungal agent are added to the silicone compound as a raw material of the silicone rubber on the cotton fabric layer 5 formed in this way, and dissolved and dissolved in a toluene solvent, and defoamed. To obtain a silicone paste, which was coated on the surface of the cotton fabric layer 5 with a knife over roll coater and dried to form a flame retardant layer 6. Thereafter, the silicone rubber impregnated in the cotton fabric layer 5 by heating and the silicone rubber constituting the flame retardant layer 6 were respectively crosslinked and polymerized to obtain a laminated sheet 7.

The amount of silicone rubber impregnated in the cotton fabric layer 5 was 45 g / m ² . Further, the amount of silicone rubber constituting the flame retardant layer 6 was 125 g / m ² .

  Next, the heat insulating layer 1, the two air-blocking layers 2, and the two laminated sheets 7 prepared as described above are laminated in the order shown in FIG. 4, that is, (Flame retardant layer 6 / cotton cloth) Layer 5) / (metal layer 4 / resin layer 3) / heat insulating layer 1 / (resin layer 3 / metal layer 4) / (cotton layer 5 / flame retardant layer 6).

  The superposed product was sewn using a sewing thread to be integrated to produce a sample of Example 1 which is the seat body 10 of the present invention. As shown in FIG. 1, two sheet fasteners 14 each having a metal fitting 13 (single wire feed) attached to one end of the belt 12 were prepared and attached to such a sample. As the belt, a belt composed of a laminate sheet / ventilation blocking layer / laminate sheet was used.

[Example 2]
( Production of Example 2 sample )
In Example 1 described above, the amount of silicone rubber constituting the flame retardant layer 6 was changed to 170 g / m ² . Example 2 was prepared in the same manner as in Example 1 except that.

[Reference Example 1]
( Production of Reference Example 1 sample )
In Example 2 above, the cotton fabric layer 5 was not impregnated with silicone rubber. That is, the amount of silicone rubber in the cotton fabric layer 5 was set to 0 g / m ² . Otherwise, the sample of Reference Example 1 was prepared in the same manner as in Example 2 above. The reference example described here is not a comparative example, but the configuration of the reference example is the invention of Japanese Patent Application No. 2009-58655, which is an unpublished prior application already filed by the present applicants. It is because it corresponds to.

[Reference Example 2]
( Reference Example 2 Preparation of sample )
In the sample of Reference Example 1, a flame retardant layer 6 was additionally formed inside the cotton fabric layer 5.
As a result, the flame retardant layer 6 is formed on both sides of the cotton fabric layer 5. When the lamination form is specified, (flame retardant layer 6 / cotton cloth layer 5 / flame retardant layer 6) / (metal layer 4 / resin layer 3) / heat insulating layer 1 / (resin layer 3 / metal layer 4) / (flame retardant layer) 6 / cotton layer 5 / flame retardant layer 6). The cotton fabric layer 5 is not impregnated with silicone rubber.

The amount of silicone rubber constituting the flame retardant layer 6 was 170 g / m ² , but the total amount of silicone rubber to be compared because the flame retardant layer 6 was formed on both sides of the cotton fabric layer 5 was 340 g / m ^2. m ² . Otherwise, the sample of Reference Example 2 was prepared in the same manner as the sample of Reference Example 1 above.

  About the Example 1-2 sample produced in this way and the reference example 1-2 sample, fire resistance evaluation was performed in the following way.

(Fire resistance)
A protective sheet is cut into a size of 200 mm × 200 mm to prepare a test sample. The test sample is wound around a communication cable having a length of 250 mm. We concluded that there was no. The test sample was then contacted with a burner flame. At this time, the part of the test sample that is in contact with the flame is a part that is wound around the communication cable, the height of the flame coming out of the burner tip is 150 mm, and the distance from the burner tip to the test sample is 70 mm. The contact temperature between the flame and the test sample was 890 ° C.

  A rod-shaped thermometer was inserted into the center of the sample that was in contact with the flame inside the test sample, the temperature after 20 minutes was measured, and the fire resistance was evaluated by the magnitude of the temperature. In addition, the temperature after 5 minutes, 10 minutes, and 15 minutes passed was also measured for reference.

  The experimental results are shown in Table 1 below.

  Consider the experimental results shown in Table 1.

( Comparison between Example 1 and Reference Example 1 )
In Example 1, the total amount of the silicone rubber used for both the flame retardant layer 6 and the cotton fabric layer 5 is 170 g / m ² . Reference Example 1 uses silicone rubber only for the flame retardant layer 6 and is not present in the cotton fabric layer 5 (not impregnated), but the total amount of silicone rubber is 170 g / m ^2. Same amount as in Example 1.

  However, the sample internal temperature of Example 1 after 20 minutes is 278 ° C., whereas that of Reference Example 1 is as high as 317 ° C. It can be seen that even if the same amount of silicone rubber is used, Example 1 is superior to Reference Example 1 in fire resistance. This revealed a synergistic effect for improving fire resistance by combining the cotton fabric layer 5 impregnated with the silicone rubber, which is a constitution of the present invention, and the silicone rubber flame retardant layer 6 formed thereon. .

  Further, in Example 1, the amount of silicone rubber in the flame retardant layer 6 is small, or the temperature rise is fast until 5 minutes, but the subsequent temperature rise is reliably suppressed by the silicone rubber impregnated in the cotton layer 5. Can be considered.

( Comparison between Example 1 and Reference Example 2 )
As described above, the total amount of the silicone rubber used for both the flame retardant layer 6 and the cotton fabric layer 5 in Example 1 is 170 g / m ² . On the other hand, in Reference Example 2, the flame retardant layer 6 is formed on both sides of the cotton fabric layer 5 and silicone rubber is used only for the flame retardant layer 6, but the total amount of silicone rubber is 340 g / m ² . Yes, 170 g / m ² more than Example 1 is used.

  However, the sample internal temperature of Example 1 after 20 minutes is 278 ° C., whereas that of Reference Example 2 is as high as 316 ° C. Also from this, the synergistic effect for improving the fire resistance by the combination of the cotton fabric layer 5 impregnated with the silicone rubber of the present invention and the silicone rubber flame retardant layer 6 formed thereon is clear.

( Comparison between Example 2 and Reference Example 2 )
The total amount of the silicone rubber used for both the flame retardant layer 6 and the cotton fabric layer 5 in Example 2 is 215 g / m ² . Against Reference Example 2 This, the use of the silicone rubber only in the flame retardant layer 6 formed on both sides of the cotton cloth layer 5, the silicone rubber combined weight was 340 g / m ^2, Example 2 More than 125 g / m ² .

  However, the sample internal temperature of Example 2 after 20 minutes is 261 ° C., whereas that of Reference Example 2 is 316 ° C., which is high.

  This reveals a synergistic effect for improving fire resistance by the combination of the cotton fabric layer 5 impregnated with silicone rubber and the silicone rubber flame retardant layer 6 formed thereon. Therefore, in the present invention, the amount of silicone rubber used can be reduced, and the protective sheet 100 can be reduced in weight and the product cost can be reduced.

  By the way, in Examples 1-2 and Reference Examples 1-2, since a layer using a cotton cloth is provided on a part of the laminated sheet 7 covered with the flame retardant layer 6, flexibility (flexibility) is provided. The water resistance was very good.

  From the above results, the effects of the present invention are clear. That is, the protective sheet for a communication cable of the present invention has a heat insulating layer and a sheet main body provided with a laminate on both sides of the heat insulating layer, and the laminate is disposed on the heat insulating layer and includes a metal layer. There is a ventilation barrier layer, a cotton fabric layer disposed on the ventilation barrier layer, and a flame retardant layer disposed on the cotton fabric layer, and the cotton fabric layer has a flame retardant material over the entire region. Therefore, it is possible to obtain a communication cable protection sheet with significantly improved fire resistance and heat resistance. Moreover, even when the same fire resistance and heat resistance effects are obtained, the amount of flame retardant material used can be reduced by combining the cotton fabric layer impregnated with the flame retardant material and the flame retardant layer formed thereon. It is possible to reduce the weight of the seat. Furthermore, the product cost can be reduced.

  As the industrial applicability of the present invention, the present invention can be used for the technology in the general communication technology field using a cable.

DESCRIPTION OF SYMBOLS 1 ... Heat insulation layer 2 ... Air-permeable blocking layer 3 ... Resin layer 4 ... Metal layer 5 ... Cotton layer 6 ... Flame retardant layer 7 ... Laminated sheet 8 ... Laminated body 10 ... Sheet main body 100 ... Protection sheet 200 ... Communication cable with protection sheet

Claims (10)

A protective sheet for a communication cable having a heat insulation layer and a sheet body comprising a laminate on both sides of the heat insulation layer,
The laminate includes a ventilation barrier layer including a metal layer disposed on the heat insulating layer, a cotton fabric layer disposed on the ventilation barrier layer, and a flame retardant layer disposed on the cotton fabric layer. Have
A protective sheet for a communication cable, wherein the cotton fabric layer is impregnated with a flame retardant material throughout the entire layer. A pair of laminates each having a ventilation barrier layer including a metal layer, a cotton cloth layer disposed on the ventilation barrier layer, and a flame retardant layer disposed on the cotton cloth layer are prepared, A communication cable protective sheet formed by bonding and
A protective sheet for a communication cable, wherein the cotton fabric layer is impregnated with a flame retardant material throughout the entire layer.   The protective sheet for a communication cable according to claim 1, wherein the heat insulating layer is one selected from the group consisting of carbon fiber, metal fiber, ceramic fiber, and acrylic fiber.   The flame retardant material impregnated in the cotton fabric layer is one selected from the group consisting of silicone rubber, chloroprene rubber, fluoro rubber, EPDM, NBR, and hydrogenated styrene thermoplastic elastomer. The protection sheet for communication cables in any one.   The communication sheet protection sheet according to any one of claims 1 to 4, wherein the ventilation blocking layer includes a laminated structure of a metal layer and a resin layer.   The said flame-retardant layer is comprised from the layer which has as a main component 1 type selected from the group of silicone rubber, chloroprene rubber, fluororubber, EPDM, NBR, and a hydrogenated styrene-type thermoplastic elastomer. The communication cable protective sheet according to any one of 5.   The protective sheet for a communication cable according to any one of claims 1 to 6, wherein the cotton cloth layer and / or the flame retardant layer contains an antifungal agent. A method for manufacturing a protective sheet for a communication cable according to any one of claims 1 to 7,
The method
A communication cable protection comprising: an impregnation step of impregnating a flame retardant material over the entire area of the cotton fabric layer; and a step of forming a flame retardant layer on the cotton fabric layer. Sheet manufacturing method. The flame retardant material is one selected from the group of silicone rubber, chloroprene rubber, fluoro rubber, EPDM, NBR, and hydrogenated styrene thermoplastic elastomer, and the flame retardant layer has silicone rubber and chloroprene rubber as its main components. , One selected from the group of fluororubber, EPDM, NBR, hydrogenated styrene thermoplastic elastomer,
9. The communication cable according to claim 8, wherein the cotton cloth layer is dried after the impregnation step, and then a flame retardant layer is applied to the surface layer of the cotton cloth layer, and then the coating film is dried, and then subjected to crosslinking polymerization as necessary. Method of manufacturing protective sheet.   A communication cable with a protective sheet formed by winding the communication cable protective sheet according to any one of claims 1 to 7 around the communication cable.

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