JP2008031800A - Duct - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a duct which is excellent in constructibility, and which is excellent in its shape retentivity even if it is exposed to a high temperature for a long period of time. <P>SOLUTION: This duct is characterized as follows: the outer periphery and/or inner periphery of a duct body are/is equipped with a thermally-expansible fireproof coating material; the thermally-expansible fireproof coating material consists of 55-85 wt.% inorganic fibers, a 5-30 wt.% thermally-expansible inorganic substance, a 5-25 wt.% inorganic binder, and a 5-15 wt.% organic binder; and the inorganic binder, which is contained in the thermally-expansible fireproof coating material, consists of a sinterable inorganic material with a melting point of 650-1,000°C. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a duct excellent in fire resistance and workability.

Conventionally, in a duct such as an air-conditioning duct or a ventilation duct of a fire use room such as a kitchen, it has been proposed to fix a fireproof coating material such as rock wool or ceramic wool on the outer peripheral surface of the duct in order to improve fire resistance. (Patent Document 1).
However, in order to improve the fire resistance of the duct, it is necessary to increase the thickness of these fireproof coating materials, and there is a problem that workability at the time of duct construction provided with the fireproof coating material is inferior.
In addition, a fire damper is installed in the smoke exhaust duct or the like in order to prevent the fire from spreading through the inside of the duct in the event of a fire. In the event of a fire or the like, the fire damper is activated to close the inside of the duct, thereby preventing further fire spread.
However, when a malfunction occurs in such a fireproof damper, there is a problem that it is not possible to prevent the spread of fire through the inside of the duct.

On the other hand, a wet slurry of a composition of rock wool 50 to 90% by weight, thermally expandable inorganic powder 5 to 25% by weight, sinterable inorganic material 5 to 10% by weight, and organic binder 2 to 10% by weight is wet-made. The resulting thermally expandable inorganic fiber felt has been proposed.
The shape of the thermally expandable inorganic fiber felt changes greatly before and after receiving heat from a fire or the like. Therefore, even after the thermally expandable inorganic fiber felt expands due to heat from a fire or the like, the thermally expandable inorganic fiber felt does not easily collapse after the expansion. The sinterable inorganic material is an essential component.
This sinterable inorganic material is sintered and integrated with the rock wool by heat such as fire. By this sintering integration, it is possible to prevent the thermally expandable inorganic fiber felt after expansion from collapsing in a short time.
From this, it is said that the said thermally expansible inorganic fiber felt can be applied to a fireproof sealing material etc. (patent document 2).
JP 2001-32993 A JP 2000-199194 A

However, when the heat-expandable inorganic fiber felt is simply used for the duct instead of the rock wool or ceramic wool, the following problems occur.
That is, as previously proposed, borax or the like having a melting point of 75 ° C. or a melting point of 1300
When a sinterable inorganic material such as sepiolite exceeding ℃ is used for the thermally expandable inorganic fiber felt, the sinterable inorganic material is sufficiently expanded before the thermally expandable inorganic material is sufficiently expanded by heat such as a fire. And the inorganic fibers are sintered and integrated, or conversely, even after the thermally expandable inorganic material is sufficiently expanded, the sintered inorganic material and the inorganic fibers are sufficiently sintered and integrated. There is a problem that the shape retention when exposed to a high temperature for a long time is not yet sufficient.
An object of the present invention is to provide a duct having excellent workability and excellent shape retention even when exposed to a high temperature for a long time.

As a result of intensive studies to solve the above problems, the inventor has a melting point of 650 to 1000 ° C.
It was found that a duct provided with the following thermally expandable fireproof coating material containing a sinterable inorganic material having a specific melting point within the range of the above range was suitable for the purpose of the present invention, and the present invention was completed.

That is, the present invention
[1] A duct provided with a thermally expandable fireproof coating on the outer periphery and / or inner periphery of the duct body,
The thermally expandable fireproof coating material comprises 55 to 85% by weight of inorganic fibers, 5 to 30% by weight of thermally expandable inorganic material, 5 to 25% by weight of inorganic binder, and 5 to 15% by weight of organic binder,
The inorganic binder contained in the thermally expandable fireproof coating material provides a duct characterized by comprising a sinterable inorganic material having a melting point in the range of 650 to 1000 ° C.
[2] The inorganic binder contained in the thermally expandable fireproof coating material is silicon dioxide 50-60.
It is characterized by comprising a sinterable inorganic material containing 10% by weight of aluminum oxide, 10 to 20% by weight of aluminum oxide, 10 to 20% by weight of calcium oxide, 1 to 10% by weight of magnesium oxide, and 8 to 13% by weight of boron oxide. The duct according to [1] is provided.

ADVANTAGE OF THE INVENTION According to this invention, it is excellent in workability | operativity and can provide the duct which is excellent also in the case where it is a case where it is exposed to high temperature for a long time.

The duct of the present invention uses a heat-expandable fireproof coating material, and this heat-expandable fireproof coating material is composed of inorganic fibers, a heat-expandable inorganic material, an inorganic binder, and an organic binder.
First, inorganic fibers used for the thermally expandable fireproof covering material will be described.
As an inorganic fiber used for this invention, a ceramic fiber etc. can be mentioned, for example.

Specific examples of such ceramic fibers include silica alumina fibers, alumina fibers, silica fibers, and zirconia fibers.
Such ceramic fibers preferably have a melting point of 1300 ° C. or higher from the viewpoint of heat resistance,
If it is 1500 degreeC or more, it is still more preferable.
In the present invention, the term “melting point” means the melting point of a substance that clearly shows the melting point, such as a pure substance, and the like for those that do not clearly show the melting point, such as a mixture.
It shall mean the softening point measured according to SR3103-1.

  The said inorganic fiber can use 1 type, or 2 or more types.

The amount of inorganic fiber used in the present invention is based on the weight of the thermally expandable fireproof coating material,
It is in the range of 55 to 85% by weight.
When the amount of the inorganic fiber is less than 55% by weight, the shape retention of the heat insulating layer is lowered, and when it is more than 85% by weight, the workability of the thermally expandable fire-resistant coating material is lowered.
The amount of the inorganic fiber used in the present invention is preferably in the range of 60 to 80% by weight.

The diameter of the inorganic fiber is usually in the range of 0.01 to 100 μm, preferably 0.1 to 100 μm.
The range is 30 μm. In addition, the inorganic fiber may be a bundle of a plurality of fibers combined with a sizing agent such as a silane coupling agent.

There is no limitation on the production method for obtaining the inorganic fiber, for example, a rod method for winding the fiber obtained by softening and drawing the inorganic fiber raw material, discharging the molten raw material from the nozzle, Examples include a pot method for winding the obtained fiber, a precursor polymer method for winding the fiber obtained by sintering the precursor of the raw material dissolved in an organic solvent as a precursor, and the like. Can do. Commercial products can be obtained as these inorganic fibers.

Examples of the inorganic fibers used in the present invention include those obtained by cutting linear ceramic fibers, and those obtained by pulverizing linear ceramic fibers.
What was obtained by cutting the above-mentioned linear ceramic fiber can be obtained as a chopped inorganic fiber, and a commercially available product obtained by pulverizing the above-mentioned linear ceramic fiber is commercially available as a milled inorganic fiber. Goods can be obtained.
These inorganic fibers can be used alone or in combination of two or more.

Next, the thermally expandable inorganic substance used in the present invention will be described.
The thermally expandable inorganic compound is not particularly limited as long as it expands when heated,
Examples thereof include vermiculite, kaolin, mica, and thermally expandable graphite. Among these, heat-expandable graphite is preferable because the foaming start temperature is low.

The heat-expandable graphite is a conventionally known substance, and powders such as natural scaly graphite, pyrolytic graphite, and quiche graphite are mixed with inorganic acids such as concentrated sulfuric acid, nitric acid, and selenic acid, concentrated nitric acid, perchloric acid, peroxygen, and the like. A graphite intercalation compound produced by treatment with a strong oxidant such as chlorate, permanganate, dichromate, hydrogen peroxide, etc., and is a crystalline compound that maintains the layered structure of carbon. .

  The heat-expandable graphite obtained by acid treatment as described above is preferably further neutralized with ammonia, an aliphatic lower amine, an alkali metal compound, an alkaline earth metal compound, or the like.

Examples of the aliphatic lower amine include monomethylamine, dimethylamine, trimethylamine, ethylamine, propylamine, and butylamine.

Examples of the alkali metal compound and alkaline earth metal compound include hydroxides such as potassium, sodium, calcium, barium, and magnesium, oxides, carbonates, sulfates, and organic acid salts.

The thermal expandable graphite preferably has a particle size in the range of 20 to 200 mesh. Granularity is 2
If it is smaller than 00 mesh, the degree of expansion of graphite is small, and a sufficient fireproof insulation layer may not be obtained. If the particle size is larger than 20 mesh, there is an advantage that the degree of expansion of graphite is large, but thermal expansion It may become difficult to be retained by the conductive inorganic material.

As a commercial item of the said thermal expansion graphite by which the neutralization process was carried out, for example, UCAR CARBON
“GRAF GUARD” manufactured by the company, “GREP-EG” manufactured by Tosoh Corporation, and the like.

  The said thermally expansible inorganic substance can use 1 type, or 2 or more types.

The compounding quantity of the thermally expansible inorganic substance used for this invention is the range of 5-30 weight% on the basis of the weight of the thermally expansible fireproof coating material used for this invention.
When the blending amount of the heat-expandable inorganic material is less than 5% by weight, the expansion volume after combustion is small, and a sufficient fireproof heat insulating layer cannot be obtained. On the other hand, when it exceeds 30% by weight, the strength of the thermally expandable fireproof coating material after expansion is lowered.
The amount of the thermally expandable inorganic material used in the present invention is preferably in the range of 10 to 25% by weight.

Next, the inorganic binder used in the present invention will be described.
As an inorganic binder used for this invention, a sinterable inorganic material etc. can be mentioned, for example.
Specific examples of the sinterable inorganic material include, for example, electrically insulating glass.

Specific examples of the electrically insulating glass include 50 to 60% by weight of silicon dioxide, 10 to 20% by weight of aluminum oxide, 10 to 20% by weight of calcium oxide, 1 to 10% by weight of magnesium oxide, and boron oxide. Can be mentioned what is called E glass and the like contained in the range of 8 to 13% by weight.

The sinterable inorganic material used in the present invention is preferable if the content of the lead metal salt and the alkali metal oxide is less than 1% by weight with respect to the weight of the sinterable inorganic material.
As the lead metal salts, for example, a _{PbO, PbO 2, Pb 3 O} 4 or the like.
Examples of the alkali metal oxide include Na ₂ O and K ₂ O.
Among the sinterable inorganic materials used in the present invention, the E glass is preferred because it has a low alkali metal oxide content and has little influence on building structural materials.

The sinterable inorganic material used in the present invention has a melting point in the range of 650 to 1000 ° C.
Thereby, even after the thermally expandable fireproof covering material used in the present invention is expanded by heat such as a fire, the inorganic fibers and the like contained in the thermally expandable fireproof covering material are kept in a unified and unitary shape. In addition to being able to do so, the shape retention may be maintained even when exposed to high temperatures for extended periods of time.

When the melting point is less than 650 ° C., because the heat-expandable fireproof coating material sufficiently expands due to heat such as fire, the sinterable inorganic material and the inorganic fiber are integrated by sintering, Inferior shape retention when exposed to high temperature for a long time. When the melting point exceeds 1000 ° C,
Even after the thermally expandable fire-resistant coating material has sufficiently expanded, the sinterable inorganic material and the inorganic fiber may not be sufficiently sintered and integrated, and similarly when exposed to high temperatures for a long time. Inferior shape retention.
The melting point is preferably 700 to 900 ° C, more preferably 750 to 850 ° C.

The sinterable inorganic material having a desired melting point can be obtained by adjusting the components contained in the sinterable inorganic material.
For example, in the case of the E glass, specifically, silicon dioxide is 55% by weight, aluminum oxide is 15% by weight, calcium oxide is 15% by weight, magnesium oxide is 5% by weight,
When boron oxide is contained at 10% by weight or the like, the melting point is 700 ° C.
By increasing the amount of calcium oxide, magnesium oxide and the like contained in the E glass, the ratio of covalent bonds such as silicon dioxide contained in the E glass can be reduced. Can be lowered to 700 ° C. or lower.

Conversely, by reducing the amount of calcium oxide, magnesium oxide, etc., the proportion of covalent bonds such as silicon dioxide contained in the E glass can be increased, so the melting point of the E glass is raised to 700 ° C. or higher. It becomes possible.

The compounding quantity of the sinterable inorganic material used for this invention is the range of 5-25 weight% on the basis of the weight of the heat-expandable fireproof coating material used for this invention.
When the blending amount of the sinterable inorganic material is less than 5% by weight or exceeds 25% by weight, when the thermally expandable fire-resistant coating material is exposed to a high temperature for a long time, its shape retention is lowered. .
The amount of the sinterable inorganic material used in the present invention is preferably in the range of 10 to 15% by weight.

The shape of the sinterable inorganic material is not particularly limited, and examples thereof include a fiber-shaped body, a wool-shaped body in which the fiber-shaped body is intertwined, and a powder-shaped body.

  When a fiber shaped body is used as the sinterable inorganic material, the diameter of the fiber is usually in the range of 0.01 to 100 μm, preferably in the range of 0.1 to 30 μm. In this case, as the fiber shaped body, a plurality of fibers combined into one by a sizing agent such as a silane coupling agent can be used.

  The method for obtaining such a fiber shaped body is not particularly limited. For example, the rod method for winding the fiber obtained by softening and drawing the raw material of the sinterable inorganic material, the molten raw material Examples of the method include a pot method that discharges from the nozzle and winds up the obtained fiber. What was obtained by these methods can be obtained as a commercial item.

  Moreover, when using a powder-shaped body as the said sinterable inorganic material, the average particle diameter of the said powder-shaped body is the range of 5-500 micrometers normally. The powdery body can usually be obtained as a commercial product.

  The said sinterable inorganic material can use 1 type, or 2 or more types.

Next, the organic binder used in the present invention will be described.
The organic binder used in the present invention is not particularly limited. For example, specifically, polyolefin resins such as polypropylene resins, polyethylene resins, poly (1-) butene resins, polypentene resins, polystyrene resins, Acrylonitrile-butadiene-styrene resin, methyl methacrylate-butadiene-styrene resin, ethylene-vinyl acetate resin, ethylene-propylene resin, polycarbonate resin, polyphenylene ether resin, acrylic resin, polyamide resin, polyvinyl chloride resin, etc. Thermoplastic resins,
Natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), 1,2-polybutadiene rubber (1,2-BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), nitrile rubber (NBR) ), Butyl rubber (IIR), ethylene-propylene rubber (EPR, EPDM), chlorosulfonated polyethylene (CSM), acrylic rubber (ACM, ANM), epichlorohydrin rubber (CO, ECO), polyvulcanized rubber (T), silicone rubber (Q), rubbers such as fluorine rubber (FKM, FZ), urethane rubber (U),
Thermosetting resins such as polyurethane resin, polyisocyanate resin, polyisocyanurate resin, phenol resin, epoxy resin,
Latexes such as the above thermoplastic resins and rubbers,
Examples thereof include emulsions such as the above thermoplastic resins and rubbers.

Of these, rubber latexes, ethylene-vinyl acetate resins, acrylic resin emulsions, and the like are preferable from the viewpoint of handleability.

  The organic binder can be used alone or in combination of two or more.

The compounding quantity of the organic binder used for this invention is the range of 5-15 weight% on the basis of the weight of the heat-expandable fireproof coating material used for this invention.
When the blending amount of the organic binder is less than 5% by weight, workability for producing the heat-expandable fireproof coating material is lowered. On the other hand, when the content exceeds 15% by weight, the shape-retaining property is lowered when the thermally expandable fireproof coating material is exposed to a high temperature for a long time.
The amount of the organic binder used in the present invention is preferably in the range of 5 to 10% by weight.

  In addition, various additives such as a colorant, an antioxidant, a flame retardant, an inorganic filler, and an adhesive can be used for the heat-expandable fireproof coating material as long as the object of the present invention is not impaired. .

Next, a method for producing the thermally expandable fireproof covering material used in the present invention will be described.
The method for producing the thermally expandable fireproof coating material is not particularly limited. For example, each component of the thermally expandable fireproof coating material is formed into a sheet shape by a papermaking method, and each component of the thermally expandable fireproof coating material. And a method of forming a sheet shape by removing the organic solvent after molding a mixture of the organic solvent and the organic solvent.

  Among these, from the viewpoint of producing the homogeneous heat-expandable fireproof coating material, a manufacturing method by a papermaking method is preferable, and among these manufacturing methods by the papermaking method, a manufacturing method by an adsorption molding method is more preferable.

Examples of the method for producing the thermally expandable fireproof coating material by a typical papermaking method include a production method according to the following process.
(1) Disperse each component of the heat-expandable fireproof coating material used in the present invention described above in a solvent using an apparatus such as a mixer or a mill to prepare a solvent slurry of each component.
(2) The solvent slurry is made by a paper making machine such as a rot former and formed into a desired shape.
(3) If necessary, the solvent is removed from the solvent slurry by means such as suction, compression, centrifugation, heating, and air blowing.
Through the above steps, the thermally expandable fireproof coating material used in the present invention can be obtained.

Next, the manufacturing method of the said heat-expandable fireproof covering material by an adsorption molding method is demonstrated.
An embodiment of this adsorption molding method is exemplified as follows with reference to FIG.
(1) For example, a solvent that does not dissolve the components of the thermally expandable fireproof coating material is prepared, and a slurry 1 is prepared in which the components of the thermally expandable fireproof coating material are suspended in the solvent. Keep it.
(2) A frame body suction port 2 for sucking the slurry 1 and each component of the thermally expandable fireproof coating material are separated from the slurry 1 provided on one side of the frame body suction port 2. The slurry is sucked by an adsorption molding device 5 provided with a filtering member 3 for the purpose and a suction device 4 for recovering the solvent from the slurry 1 through the filtering member 3.
(3) For example, a partition for orienting inorganic fibers contained in the slurry 1 in one direction can be provided between the frame body inlet 2 of the adsorption molding device 5 and the filtering means 3 ( Not shown). Since this partition is provided with one side of each section sufficiently longer than the other side, the inorganic fibers 6 are sequentially deposited from the filtration member 3 side along the direction of the long side in the suction molding apparatus 5. .
For convenience of explanation, in FIG. 1, the length of the inorganic fiber is drawn longer than the actual length.
The partition is pulled out from the frame body suction port 2 after the suction operation is completed or while performing the suction operation, so that a filtered material in which the inorganic fibers are substantially oriented in a certain direction is formed inside the adsorption molding device 5. .
(4) After suction, the solvent contained in the obtained filtrate is removed by means such as suction, compression, centrifugation, heating, and air blowing.
(5) Subsequently, it can be formed into a desired shape using means such as cutting.
Through the above steps, the thermally expandable fireproof coating material used in the present invention can be obtained.

As said filtration member, what has a filter paper, a filter cloth, a filter, a metal mesh etc. can be mentioned, for example.
The filtering member can be used alone or in combination of two or more.

  By appropriately selecting the shape of the frame body inlet, the thermally expandable fire-resistant coating material having a desired shape can be obtained.

  In addition, the said solvent has a preferable thing which does not melt | dissolve the various components of the said heat-expandable fireproof coating material, For example, water, methanol, etc. can be mentioned. Among these, from the viewpoint of handleability, the solvent is preferably water.

  When the slurry is sucked by the above operation, the orientation direction of the inorganic fibers can be aligned in the suction direction, and the inorganic fibers contained in the thermally expandable fireproof coating material are removed from the surface of the thermally expandable fireproof coating material. Can be substantially oriented in the direction normal to the.

  When the inorganic fibers are substantially oriented in the normal direction to the surface of the thermally expandable fireproof coating material, the thermally expandable fireproof coating material is more thermally expanded than the thickness direction of the thermally expandable fireproof coating material. Greatly expands in the direction of the surface of the fireproof covering material.

  As a result, even if there is an opening in a part of the thermally expandable fireproof covering material and a part not covered with the thermally expandable fireproof covering material in a part of the duct, these openings or covers are covered. A non-existing portion can be closed by expansion based on heat such as a fire.

  As a specific example of the method of forming a mixture with the organic solvent, for example, an organic solvent in which the organic binder is dissolved is mixed with inorganic fibers, a thermally expandable inorganic material, a sinterable inorganic material, and an organic binder. There is a method in which an organic solvent is removed after preparing a mixture and forming it into various shapes with a molding machine. The heat-expandable fireproof covering material can also be obtained by this method.

  The thickness of the heat-expandable fireproof covering material used in the present invention is usually in the range of 0.1 to 100 mm, preferably 3 to 10 mm.

Bulk density of the heat-expandable fire protection material is usually in the range of 0.15~0.35g / cm ^3, preferably ranges from 0.2 to 0.3 g / cm ^3.

Next, the duct body used in the present invention will be described.
The duct body is not particularly limited. For example, the duct body is used for an air-conditioning duct such as a building, a smoke exhaust duct, an incinerator, a fire use room ventilation duct such as a kitchen, and the like. Examples include those used for vehicles such as passenger cars and ships, and intake and exhaust ducts such as hulls.
One or two or more of these duct bodies can be used.

The duct body is usually made of a metal such as aluminum, steel, stainless steel or copper, but is not limited thereto.
The duct may have one or two or more types such as a square, a rectangle, a circle, an ellipse, or a polygon in cross section.

Next, a method for installing the thermally expandable fireproof covering material on the duct body will be described.
The heat-expandable fireproof covering material can be installed on the outer periphery of the duct body, can be installed on the inner periphery of the duct body, or installed on both the outer periphery and the inner periphery of the duct body. You can also.
Moreover, it is not necessary to install the said heat-expandable fireproof coating material in all the said duct main bodies, and there may exist a part in which the said heat-expandable fireproof coating material is not installed in part.

Examples of means for installing the thermally expandable fireproof covering material on the duct body include a welding pin, a self-drilling screw, a tapping screw, a tacker, and a nail.
For example, it is also possible to install the thermally expandable fireproof covering material on the duct body using a double-sided adhesive tape, an adhesive, or the like.

The heat-expandable fireproof covering material may be installed in a single layer on the duct body, or may be installed in multiples of double or more.
Moreover, in addition to the said heat-expandable fireproof covering material, 1 type, or 2 or more types, such as a nonwoven fabric, metal foil, and aluminum glass cloth, can also be further installed.

Next, an embodiment of the duct according to the present invention will be described with reference to the drawings.
FIG. 2 illustrates a cross-sectional view of the main part of the first embodiment of the duct according to the present invention.
As illustrated in FIG. 2, the duct of the present invention includes the thermally expandable fire-resistant coating material 10 on the outer periphery of the duct body 9.
The thermally expandable fireproof covering material 10 is fixed to the duct body 9 by welding pins 11.

FIG. 3 illustrates a cross-sectional view of an essential part of a second embodiment of the duct according to the present invention.
As illustrated in FIG. 3, the duct of the present invention is provided with the thermally expandable fireproof covering material 10 on the inner periphery of the duct body 9.
The thermally expandable fireproof covering material 10 is fixed to the duct body 9 with an adhesive.

FIG. 4 illustrates a perspective view of a main part of a third embodiment of the duct according to the present invention.
As illustrated in FIG. 4, the duct according to the present invention includes the thermally expandable fireproof covering material 10 on both the inner periphery and the outer periphery of the duct body 9.

Hereinafter, the embodiments of the present invention will be described in more detail by way of examples. However, the present invention is not limited to these examples.
・ Reference Examples 1-3
Ceramic fibers (“SC bulk” manufactured by Nippon Kayaku Thermal Ceramics Co., Ltd.), thermally expandable graphite (“GREP-EG” manufactured by Tosoh Corporation), and glass fibers (“Glaslon” manufactured by Asahi Fiber Glass Co., Ltd.) with the mixing ratio shown in Table 1. “Chopped strand”, E glass long fiber, fiber diameter: about 10 μm, fiber length: about 3 mm), glass wool (“Glaslon wool” manufactured by Asahi Fiber Glass Co., Ltd., fiber diameter: about 4-7 μm), acrylic resin latex ( An aqueous dispersion of “LX874” manufactured by Nippon Zeon Co., Ltd.) was prepared, and a thermally expandable fireproof coating material having a bulk density and thickness shown in Table 1 was prepared by a papermaking method.
The following performance evaluation was performed about the produced said heat-expandable fireproof covering material. Reference examples 2 and 3 were also carried out in the same manner as in Example 1 with the compounding ratios shown in Table 1. The results are summarized in Table 1.

[Measurement of expansion ratio and stress at break]
Using the samples obtained in Reference Examples 1 to 3, the sample was heated in an electric furnace at a temperature of 1000 ° C. for 1 hour, and the expansion ratio was the ratio of the thickness after heating to the thickness before heating (thickness after heating / The thickness was calculated as the thickness before heating.

Further, as an index of the shape retention property of the thermally expandable fire-resistant coating material after expansion by heating, the sample after heating was subjected to a 0.25 cm ² indenter using a compression tester (“Finger Feeling Tester” manufactured by Kato Tech). The breaking stress was measured at a compression rate of 0.1 cm / s.

  The results are shown in Table 1.

Note that when the stress at break of the sample is 0.05 kgf / cm ² or more, even if a fire resistance test is performed in a state of being held vertically, the shape of the thermally expandable fireproof coating material after the heat expansion is Fireproof performance can be fully exhibited without breaking down.

Reference examples 4-5
Production of thermally expandable material Ceramic fiber (“SC Bulk” manufactured by Nikka Chemical Co., Ltd.), thermally expandable graphite (
"GREP-EG" manufactured by Tosoh Corporation), glass fiber ("Glasslon Chopped Strand" manufactured by Asahi Fiber Glass Co., Ltd.), E glass long fiber, fiber diameter: about 10 μm, fiber length: about 3 mm), glass wool (Asahi Fiber Glass Co., Ltd.) “Glasslon Wool”, fiber diameter: about 4-7 μm)
A slurry was prepared by dispersing acrylic resin latex (“LX874” manufactured by Nippon Zeon Co., Ltd.) in water at a blending ratio shown in Table 2. Using a mold with a width of 300 mm x length of 450 mm x thickness of 30 mm, a heat-expandable fireproof coating with a predetermined bulk density in which inorganic fibers are oriented in a substantially constant direction by suction (adsorption molding method) from the thickness direction by a papermaking method After producing the material, it was sliced in the direction perpendicular to the orientation method of the inorganic fibers to obtain a heat-expandable fireproof coating material having a predetermined thickness.
[Evaluation of the obtained sample]
About the produced heat-expandable fireproof coating material, volume expansion ratio was evaluated.

  The 50 mm square heat-expandable fireproof coating material is heated in an electric furnace at a temperature of 1000 ° C. for 1 hour, and the width, length, and thickness are measured, and the volume expansion ratio is the volume after heating, before heating. The ratio to the volume (volume after heating / volume before heating) was calculated.

The heated sample preferentially expanded mainly in a direction parallel to the fiber direction, but expansion was also observed in the fiber direction, that is, the thickness direction.

Insulation test method used for exhaust ducts (Facilities for fire and disaster prevention, etc., Performance Evaluation Committee, 2000
Based on May 22, 2011), the performance evaluation of the thermally expandable fireproof coating material in the duct of the present invention was performed.
On the back side of a stainless steel plate having a length of 500 mm, a width of 500 mm, and a thickness of 0.5 mm, each thermally expandable fire-resistant coating material having the same composition as shown in Table 1 and Table 2 was laminated to prepare a test specimen.
The temperature at a position 100 mm away from the surface of the stainless steel plate is I until 5 minutes after the start of heating.
Heating was performed so as to follow the heating curve defined in SO834 and at 550 ° C. from 5 minutes to 30 minutes.
As a result of measuring the back surface temperature of the heat-expandable fireproof coating material, in any case, the average temperature is room temperature + 1
The maximum temperature was 40 ° C. or lower and the maximum temperature was room temperature + 180 ° C. or lower, which satisfied the regulations.

It is a schematic principal part sectional drawing which shows the outline of the apparatus for manufacturing the thermally expansible fireproof covering material by an adsorption molding method. It is a typical principal part sectional view of the duct concerning the present invention. It is a typical principal part sectional view of the duct concerning the present invention. It is a model principal part perspective view of the duct which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Slurry 2 Frame body inlet 3 Filtration member 4 Suction apparatus 5 Adsorption molding apparatus 6 Inorganic fiber 7 Piping 8 Slurry tank 9 Duct body 10 Thermal expansion fireproof covering material 11 Welding pin

Claims (2)

A duct having a thermally expandable fireproof coating on the outer periphery and / or inner periphery of the duct body,
The thermally expandable fireproof coating material comprises 55 to 85% by weight of inorganic fibers, 5 to 30% by weight of thermally expandable inorganic material, 5 to 25% by weight of inorganic binder, and 5 to 15% by weight of organic binder,
The duct characterized by the inorganic binder contained in the said thermally expansible fireproof covering material consisting of a sinterable inorganic material whose melting | fusing point is the range of 650-1000 degreeC. The inorganic binder contained in the thermally expandable fireproof coating material is 50 to 60% by weight of silicon dioxide, 10 to 20% by weight of aluminum oxide, 10 to 20% by weight of calcium oxide, 1 to 10% by weight of magnesium oxide, and 8 to 8% of boron oxide. The duct according to claim 1, comprising a sinterable inorganic material containing 13% by weight.

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