JPS61279549A - Fire protecting material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides insulation protection for combustible base materials such as electric wires and cables from flames during fires, and exhibits remarkable effects in preventing the base materials from burning and maintaining their functions. This relates to fireproofing materials.

[Prior art] Electrical wires and cables are generally covered with flammable rubber or plastic, and electric lines where electric wires and cables are laid in groups are subject to conditions that are extremely flammable once a fire occurs. Fires may spread along the power lines, causing secondary disasters.

Therefore, today, in buildings, factories, power plants, etc., in order to prevent the spread of fire through the power lines, fire-retardant paint is being applied to the power lines.

Fire-retardant paint is applied so that the thickness after drying is usually 15 am or more.
E 5td) 383-1974: Demonstrates the ability to prevent wires and cables from spreading fire as evaluated by vertical tray combustion test. Fire-retardant paint can prevent the spread of fire on electric wires and cables, and prevent fires from spreading along electric lines, but their insulation performance is insufficient, so the heat from a fire can cause damage to electric wires and cables that transmit power or Difficulty maintaining transmission functionality.

Therefore, as a fire protection measure for existing or corroded electric wires and cables, there is a need for a fireproofing material that has better fireproofing performance than the fire spread prevention effect of conventional fireproofing paints. In order to maintain the functionality of wires and cables even after a fire, the rubber or plastic insulation covering the wires and cables needs to be insulated and protected from softening and melting. For this type of purpose, paints and plastics that expand and expand with the heat of a fire to form an insulating carbonized layer have been developed, and it has been confirmed that they have significantly higher insulation protection effects than conventional non-foaming fire prevention paints. However, it is not necessarily sufficient in terms of workability and reliability.

Foaming fire prevention paint is a paint vehicle mixed with a large amount of agent that forms a foaming carbonized layer when exposed to flames during a fire.
Paints that expand and carbonize to a thickness of about 100 to 200 times have been obtained, but the thickness that can be applied at one time is about 001 to 0゜2jI11. has the disadvantage that the coating film will crack when drying unless it is applied repeatedly. In addition, fire-retardant sheet materials containing a large amount of chemicals that form a foamed carbonized layer in the plastic are easy to handle, but the foaming ratio is from several times to more than 10 times, and compared to foamed fire-retardant paints, they provide better heat insulation. Less effective.

[Problems to be Solved by the Invention] As mentioned above, non-foaming fireproofing paints have problems with heat insulation performance, and foaming fireproofing paints have problems with workability and reliability.
Fireproof sheet materials also have problems with their thermal insulation performance.

The purpose of the present invention is to solve the problems of the prior art described above,
To provide a fireproofing material particularly excellent in heat insulation protection effect, which can insulate and protect electric wires and cables even in the event of a fire and maintain their functions by covering parts of existing electric wires and cables with a high risk of fire.

Means for Solving Problem E] The fireproofing material according to the present invention comprises a surface layer made of a nonwoven fabric impregnated with a foamable fireproofing paint, an intermediate layer made of metal foil,
It is a laminate of three layers including a back layer made of inorganic fibers. In particular, a nonwoven fabric with a bulk specific gravity of 0.2 a/cm or less is used, and the foamable fireproofing paint is impregnated onto the nonwoven fabric at a rate such that the bulk specific gravity after impregnating and drying is 0.6 g/CI3 or more. It is.

[Function] The nonwoven fabric used in the present invention is a sheet obtained by arranging fibers in a cloth or mat shape using an appropriate method and bonding the fibers together using an adhesive or the fusing force of the fibers themselves. Fibers include cotton, rayon, acetate, nylon, polyester, and formalized polyvinyl alcohol.

Furthermore, it is preferable that the above-mentioned nonwoven fabric can be impregnated with a large amount of foamable fireproofing paint, has a bulk specific gravity of 0.2 o/cn+3 or less, and has a thickness of about 1 to 4 shoes. This nonwoven fabric is passed through a foamable fireproofing paint, and then appropriately compressed with a roller or the like to control the amount of adhesion, and then dried. It is desirable for the fire prevention performance to adjust the amount of the foaming fire prevention paint adhered so that the weight after drying is at least 3 times that of the nonwoven fabric, that is, the bulk specific gravity is 0.6a/ce3 or more, and the greater the amount of adhesion m, the more the surface layer will foam. Magnification increases. When foaming fire protection paint is formed into a single coating film, cracks occur when drying if the thickness exceeds 01281, but the surface layer in the present invention can be formed by selecting the thickness of the nonwoven fabric as the base material. A heat-foamable fireproofing layer of any thickness can be obtained by a single impregnation operation with the foamable fireproofing paint, and no cracks are observed in the foamable fireproofing paint.

This is thought to be because the presence of the nonwoven fabric base material equalizes the drying rate and the reinforcing effect of the fibers prevents cracks.

In addition, when a fire is applied to the surface layer made of nonwoven fabric to which the foamable fireproofing paint is attached, a foamed carbonized layer is well formed.

On the other hand, when a sheet of inorganic fibers is impregnated with foamable fireproofing paint and exposed to fire, foaming is significantly inhibited and the insulation effect is small.

The reason for this is that in non-am fiber sheets to which foamable fireproofing paint is attached, the inorganic fibers do not melt in the event of a fire and maintain their original shape, which suppresses the foaming expansion of foamable fireproofing paint. This is thought to be due to the fact that in the case of a nonwoven fabric made of organic fibers to which a fireproofing paint is attached, the organic fibers melt or carbonize in a fire, so that the effect of inhibiting the expansion of the foaming fireproofing paint is small.

The intermediate layer used in the present invention is made of metal foil, and in order to integrate the surface layer with the surface layer via this metal foil, a minimum amount of adhesive is applied to both the front and back surfaces of the metal foil as necessary. Layers may be laminated. Suitable materials for the metal foil include copper, lead, aluminum, and the like. The metal foil has the effect of reflecting and shielding heat caused by a fire, dissipating the heat in the length direction, and preventing heat transfer toward the base (wire/cable covering W1).

Since the back layer used in the present invention is a heat insulating layer made of inorganic fibers, it prevents heat from being directly transmitted from the metal foil of the intermediate layer to the cable sheath. The inorganic fiber material is selected from glass cloth, mat, rock wool, etc.

The thicknesses of the surface layer, intermediate layer, and back layer are appropriately selected in combination depending on the heat insulation, heat dissipation performance, and required heat resistance performance of each layer.

[Example] Hereinafter, one example and a comparative example of the fireproofing material according to the present invention will be specifically described.

FIG. 1 is a sectional view showing an embodiment of the fireproofing material according to the present invention. This fireproofing material 1 has a surface WJ1A made of a nonwoven fabric impregnated with a foamable fireproofing paint, and an intermediate layer 1B made of metal foil. , and a back layer 1C made of inorganic fibers. When using this fireproofing material 1 as a fireproofing material for electric wires and cables, as described below, 1! The back side of fireproofing material 1 on the outer circumference of the wire/cable! ! 11C and wrap it so that the surface 111A is on the outside, and fix it with nonflammable binding wire, metal fittings, etc. First, a thick nonwoven fabric made of felt-like polyester fibers with a thickness of 2.0 layers and a bulk specific gravity of 0.1 a/c
-218) with foaming fire protection paint (e.g. polyvinyl acetate emuldimine mixed with a large amount of agent that forms a foamed carbonized layer, resin content 15%9 foamed carbonized layer forming agent 43%)
and 42% water) to form a sheet with a bulk specific gravity of 0.9a/cm' after drying.
A surface layer 1A of the fireproofing material 1 of the present invention was prepared. Intermediate 111B
As the gold fi foil, aluminum foil with a thickness of 0.2 mm was used, and as the inorganic II fiber, which would become the back layer 1C, rock wool fiber was molded into a felt shape and had a thickness of 5 JII.
A fire-resistant insulation material (for example, "New Felton" manufactured by Nippon Abest Co., Ltd.) was used.

A thin layer of polyvinyl acetate emulsion adhesive is applied to both sides of the metal foil, and the surface layer 1A and back layer 1C are bonded through the metal foil.
The fireproofing material 1 of the present invention was made by overlapping and adhesively laminating the materials.

In order to confirm the fire protection performance of this fire protection material 1, as shown in FIG. A test was conducted in which the fireproofing material 1 of the present invention was wrapped around the outer circumference of a logarithm 10 polyethylene insulation and polyethylene sheath, both ends of which were fixed with binds 1113, and the flame of the burner 4 was applied to the fireproofing material 1 to continue heating for 60 minutes. rank [A
The surface temperature of the cable sheath was measured at 12B, and the temperature near the surface of the fireproof material 1 was measured and recorded at 12B using a thermal lightning pair (not shown). The heating test was conducted while adjusting the flame of the burner 4 so that the temperature near the surface of the fireproofing material 1 approximated the standard heating curve specified in JISA1304. The relationship between time and temperature for this heating test is shown graphically in FIG.

As can be seen from FIG. 3, the fireproof material 1 of the present invention has excellent heat insulation performance, and the cable sheath surface temperature remained at about 135° C. even after 60 minutes. After the test was completed, there was no change in the insulation resistance between each cable core (not shown), and when the cable was disassembled after cooling and its appearance was examined, the cable sheath was slightly deformed, but no abnormality was found in the cable core. There wasn't.

As a comparative example, the thickness is 0.34 am and the bulk specific gravity is 0.440/
Using a non-woven fabric made of C13 polyester fiber, a surface layer was prepared by impregnating the non-woven fabric with the foamable fireproofing paint used in the above example and adhering it to a bulk specific gravity of 0.8 o/cm3 after drying. The structure was otherwise identical to that of the example, and the test results are also shown in FIG.

As a result of the fact that only a small foamed carbonized layer was formed on the surface layer of the fireproofing material in this comparative example, the insulation effect was not sufficiently exhibited, and the cable sheath surface temperature reached 270℃ after 60 minutes.
The temperature was raised to ℃. When the insulation resistance between the cable cores was measured after cooling to room temperature, there were cable cores with significantly lower insulation resistance. When the fireproofing material was removed, the cable sheath was significantly melted and deteriorated, and when the cable core was examined with the cable sheath removed, it was found that some of the cable core had been melted and deformed, exposing the conductor.

[Effects of the Invention] According to the present invention, a fireproofing material can be obtained which has a remarkable effect on insulating and protecting the base material and preventing its combustion and maintaining its functions. It has the effect of being useful for fire protection of various base materials that need to be prevented.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing one embodiment of the present invention, Figure 2 (A)
, (B) are a side view and a front view schematically showing the means for testing fire retardant materials, respectively, and FIG. 3 is a graph showing the test results. 1... Fire prevention material. 1A...Surface layer. 1B...middle layer. 1C... Back layer. 2...Electric wire/cable. 3... Bind line. 4...Burner. A and 8--Concentration measurement positions. Agent Patent Attorney Sato Fujio Kaya 10 Uni 1 + Hotazai $w (-u)

Claims (2)

[Claims] (1) A fireproof material comprising three layers: a surface layer made of a nonwoven fabric impregnated with a foamable fireproofing paint, an intermediate layer made of metal foil, and a back layer made of inorganic fibers. (2) The nonwoven fabric has a bulk specific gravity of 0.2 g/cm^3 or less, and the foamable fireproofing paint is used at a ratio of the nonwoven fabric such that the bulk specific gravity after impregnating and drying is 0.6 g/cm^3 or more. The fireproofing material according to claim 1, which is impregnated.