JPH05295351A - Thermally expandable heat-insulating sealing material - Google Patents

Abstract

PURPOSE:To provide the objective material which exhibits a high flexibility, expansion ratio, and a good shape retention. CONSTITUTION:This material comprises 45-60wt.% inorg. fiber, 5-10wt.% aramid fiber, 10-20wt.% rubber, and 10-25wt.% expanded graphite. Since the material forms a heat-insulating sealing layer in the gap of a building in fire, it is suitable to be used for preventing spreading of fire.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a flexible heat-expandable heat-insulating sealing material using expansive graphite as an expansive material. The present invention relates to a seal material that can prevent the spread of smoke and the diffusion of smoke at the same time by forming an adiabatic sealing layer between openings (cable passages, ventilation holes) and inner and outer walls.

[0002]

2. Description of the Related Art Conventionally, heat-expandable materials used for fire protection include expansive graphite as a main component, alkali silicate (water glass) as a main component, and flame-retardant elastomers. It is publicly known that an organic foaming agent is added, but the one using alkali silicate has a low expansion start temperature of 150 ° C., but has a small expansion coefficient of 5 to 6 times and absorbs carbon dioxide in the air. However, there was a drawback that the expansion performance was lowered.
In addition, although the flame retardant elastomer using an organic foaming agent can be increased in initial expansion ratio by the amount of the foaming agent added, there is still a problem in the long-term stability of the foaming agent, and in order to improve flame retardancy, it is inorganic. If a large amount of filler is added, there is a drawback that the expected foaming cannot be obtained because the foaming gas leaks. Furthermore, when expandable graphite is used, the expansion start temperature is as high as about 200 ° C., but the expansion ratio is as high as 10-20 times,
In addition, the expansion performance tends to be relatively maintained even after a long period of time. However, when a large amount of expandable graphite is used, it tends to become brittle, and it is difficult to obtain a molded article having good flexibility only with the mixture. Further, since expanded graphite is easily scattered, shape retention after expansion is generally worse than that of alkali silicate type.

Therefore, an object of the present invention is to provide a heat-expandable heat-insulating sealing material having good flexibility, high expansion ratio and good shape retention.

[0004]

That is, the heat-expandable heat-insulating sealing material according to the present invention comprises 45-60% by weight of inorganic fibers,
It is characterized by containing 5 to 10% by weight of aramid fiber, 10 to 20% by weight of rubber, and 10 to 25% by weight of expandable graphite.

[0005]

In the heat-expandable heat-insulating sealing material of the present invention, when heat is transferred to the expandable material due to a fire or the like, the expandable graphite starts to expand at an initial temperature of about 200 ° C. and the rubber as the binder flows. start. At this time, if the temperature rises rapidly, the expansive graphite explosively expands and scatters,
By adding the aramid fiber having good entanglement with the rubber, it can be expanded while suppressing it. Also, the aramid fiber is carbonized in this process without self-burning,
Contributes to shape retention. Furthermore, as the temperature rises, the binder rubber and expansive graphite burn,
The inorganic fibers form a heat insulating seal layer and can prevent the spread of fire.

The heat-expandable heat-insulating sealing material of the present invention contains 45 to 70% by weight of inorganic fibers, 5 to 10% by weight of aramid fibers, 10 to 20% by weight of rubber, and 10 to 25% by weight of expandable graphite. .. As the inorganic fibers, for example, artificial fibers such as glass fibers, rock wool, ceramic fibers or natural mineral fibers such as sepiolite and wollastonite can be used. When the content of the inorganic fibers is less than 45% by weight,
It becomes difficult to maintain the shape of the heat insulating layer after the rubber, aramid fiber and expansive graphite have been burned and disappeared, and when it exceeds 70% by weight, the sealing material is flexible when formed into a sheet or rope. Is impaired, which is not preferable.

When the content of aramid fiber is less than 5% by weight, flexibility is not obtained when molded into a sheet or rope, and the rubber, expandable graphite and inorganic fiber are sufficiently entangled. I can't get sex. On the other hand, if it exceeds 10% by weight, the aramid fibers are often entangled with each other, and the expansion is excessively suppressed to lose the effectiveness, which is not preferable.

Further, as the rubber, for example, NBR, SB
R, IR, acrylic rubber, silicone rubber, etc. can be used,
Also, latex of these rubbers can be used. If the amount of the rubber compounded is less than 10% by weight, a sufficient binder effect cannot be obtained, and if it exceeds 20% by weight, it becomes difficult to maintain the shape after the rubber is burned off, which is not preferable.

As the expansive graphite, one obtained by treating naturally obtained crystalline flake graphite with an acid so as to have a thermal expansion property is used. Among them, a particle size of 10 to 60 mesh is particularly preferable. It is preferable to have one. This is because the larger the particle size is, the larger the expansion ratio is, and thus the expansion effect is easily obtained when the heat-expandable heat-insulating sealing material is used. If the compounding amount of the expandable graphite is less than 10% by weight, a sufficient expansion effect cannot be obtained, and if it exceeds 25% by weight, it becomes difficult to maintain the shape after expansion, which is not preferable.

In addition to the above components, a rubber anti-aging agent and a rubber flame retardant can be added to the heat-expandable heat-insulating sealing material of the present invention. As the rubber anti-aging agent, for example, an amine / ketone anti-aging agent (TMDQ) can be used, and the compounding amount thereof is within the range of 0.5 to 3% by weight based on the total amount of the above components. .. In addition, chlorinated paraffin or the like can be used as a flame retardant for rubber, and its compounding amount is about 3 to 7% by weight based on the total amount of the above components excluding the antioxidant.

The heat-expandable heat-insulating sealing material having the above-mentioned composition of ingredients can be molded into a sheet or rope and used. The sheet-shaped or rope-shaped sealing material can be manufactured, for example, as follows.
First, a rubber paste or latex in which rubber is dissolved with an organic solvent such as toluene, acetone, or MEK is added to the inorganic fiber,
Aramid fiber, expansive graphite, etc. are wet mixed to form a clay-like mixture. A flexible sheet or rope can be obtained by extruding this into a sheet shape or a rope shape with an extrusion molding machine and then removing the organic solvent or evaporation in a drying furnace. Alternatively, the clay-like mixture may be formed into a sheet by a roll plate forming machine, and then dried to obtain a sheet, or the sheet may be obtained by simultaneously performing plate formation and drying with a thermal plate roll. it can.

[0012]

【Example】

Example Fiber raw materials (inorganic fiber, aramid fiber) shown in Table 1 below, expansive graphite, and rubber paste (N
BR) and the antioxidant are mixed and stirred using a kneader type stirrer to prepare a clay-like mixture, and the clay-like mixture is extruded into a sheet (2 mm) using an extruder, and then in a hot air drying furnace. The solvent was scattered and dried to obtain a test sample. Table 1 also shows various characteristics of the obtained product of the present invention, comparative product and conventional product. The conventional product is a sheet-shaped molded product obtained by applying a mixture of 50 g / M ² of glass fiber fleece as a carrier and using toluene as a solvent in the same weight as the compounding composition of the conventional product in Table 1, followed by drying.

[0013]

[Table 1]

Differential thermal analysis was carried out using 4.3 mg each of the product 2 of the present invention and the conventional product obtained as described above. The result is shown in FIG. As can be seen from the results of FIG. 1, in the conventional product, the organic binder is burned out by 480 ° C., whereas in the product 2 of the present invention, the aramid fiber substitutes for the binder and maintains the shape up to 605 ° C. Also,
2 to 5 are normal products of the conventional product and the product 2 of the present invention and 1000.
It is a photograph showing a cross-sectional state of a product heated at ℃. As is clear from FIG. 5, it can be confirmed that in the product 2 of the present invention, a strong seal layer was formed without the expansion layer of the inorganic fibers collapsed even when heat-treated at 1000 ° C.

[0015]

The heat-expandable heat-insulating sealing material according to the present invention comprises 45-60% by weight of inorganic fibers and 5-1 of aramid fibers.
0% by weight, rubber 10 to 20% by weight and expandable graphite 10 to
A flexible sealing material containing 25% by weight of expansive graphite as an expansive material.
For example, the gap between the door and the door frame, the wall opening (cable pipe passage, ventilation hole) and the heat insulating seal layer formed between the inner wall and the outer wall can prevent fire spread and smoke diffusion. Play.

[Brief description of drawings]

FIG. 1 shows the results of a suggested thermal analysis of a conventional product and the product 2 of the present invention, in which the broken line is the conventional product and the solid line is the product 2 of the present invention.

FIG. 2 is a photograph showing a cross-sectional state of a conventional product, a normal product.

FIG. 3 is a photograph showing a cross-sectional state of a conventional heat-treated product.

FIG. 4 is a photograph showing a cross-sectional state of a normal product of the present invention.

FIG. 5 is a photograph showing a cross-sectional state of a heat-treated product of the present invention.

Claims (1)

[Claims] 1. A heat-expandable heat insulating material comprising 45 to 60% by weight of inorganic fibers, 5 to 10% by weight of aramid fibers, 10 to 20% by weight of rubber, and 10 to 25% by weight of expandable graphite. Seal material.