JP2006213537A - Thermally expansive inorganic material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermally expansive inorganic material which contributes to suppressing the expansion of damages such as the spread of fire or the diffusion of smoke to the minimum even when the fire breaks out and has shape holding property even when being exposed to a high temperature for a long period of time. <P>SOLUTION: The thermally expansive inorganic material has a composition comprising 55-85 wt.% inorganic fiber, 5-30 wt.% thermally expansive inorganic material, 5-15 wt.% organic binder and 5-25 wt.% sintering inorganic material having 650-1,000°C melting point. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thermally expandable inorganic material.

Conventionally, a heat-expandable inorganic material composed of inorganic fibers, heat-expandable graphite, a sinterable inorganic material, and the like has been proposed for applications such as a seal material for a fire door gap and a fireproof felt (Patent Document 1).
Patent Document 2 and Patent Document 3).
The thermally expandable inorganic material expands due to heat generated by a fire or the like. If the thermally expansive inorganic material is attached in advance to the clearance of the fire door, the gap is closed by the expansion function of the thermally expansive inorganic material even in the event of a fire. This makes it possible to prevent the spread of damage such as fire spread and smoke diffusion.
Thus, the shape of the thermally expandable inorganic material changes greatly before and after receiving heat from a fire or the like. In order to prevent the thermally expandable inorganic material from being easily collapsed even after being expanded by heat due to fire or the like, a sinterable inorganic material is an essential constituent requirement for the thermally expandable inorganic material. Has been.
The sinterable inorganic material is sintered and integrated with the inorganic fibers contained in the thermally expandable inorganic material by heat such as fire. By this sintering integration, the thermally expandable inorganic material after expansion can be prevented from collapsing in a short time, and can be used as a sealing material or the like.
Japanese Patent No. 2516556 Japanese Patent No. 2619818 JP 2000-199194 A

However, as suggested in the previous proposal, when a sinterable inorganic material such as boric acid having a melting point of about 180 ° C. or sepiolite having a melting point exceeding 1300 ° C. is used, the thermal expansion is caused by heat from a fire or the like. Even if the sinterable inorganic material and the inorganic fiber are sintered and integrated before the expandable inorganic material is sufficiently expanded, or after the thermally expandable inorganic material is sufficiently expanded, There has been a problem that the caustic inorganic material and the inorganic fiber are not sufficiently sintered and integrated, and the shape retainability when exposed to a high temperature for a long time is not yet sufficient.
An object of the present invention is to provide a thermally expandable inorganic material having excellent shape retention even when exposed to high temperatures 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 the following thermally expansible inorganic materials including a sinterable inorganic material having a specific melting point within the range of the above range meet the purpose of the present invention, and the present invention has been completed.

That is, the present invention
55 to 85% by weight of inorganic fiber, 5 to 30% by weight of thermally expandable inorganic substance, 5 to 1 of organic binder
A thermally expandable inorganic material comprising 5% by weight and 5-25% by weight of a sinterable inorganic material having a melting point in the range of 650 to 1000 ° C. is provided.

ADVANTAGE OF THE INVENTION According to this invention, even if it is a case where it is exposed to high temperature for a long time, the thermally expansible inorganic material which is excellent in the shape retainability can be provided.

First, the inorganic fibers used in the present invention will be described.
The inorganic fibers used in the present invention are not particularly limited, and examples thereof include ceramic fibers.
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 melting point means a melting point for a substance that clearly shows the melting point, such as a pure substance, and a substance that does not clearly show the melting point, such as a mixture, in JIS R3103-1. It shall mean the softening point measured accordingly.

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

The compounding quantity of the inorganic fiber used for this invention needs to be 55 to 85 weight% on the basis of the weight of the thermally expansible inorganic material of this invention.
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 exceeds 85% by weight, the workability of the thermally expandable inorganic material of the present invention 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, Obtained by a method such as 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. A thing etc. can be obtained as a commercial item.

Next, the thermally expandable inorganic substance used in the present invention will be described.
The thermally expandable inorganic compound used in the present invention is not particularly limited as long as it expands when heated, and 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 an inorganic acid such as concentrated sulfuric acid, nitric acid, selenic acid, concentrated nitric acid, perchloric acid, peroxygen, and the like. It is a crystalline compound that maintains the carbon layer structure by producing a graphite intercalation compound by treatment with a strong oxidizing agent such as chlorate, permanganate, dichromate, or hydrogen peroxide. .

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 heat insulating layer cannot be obtained. If the particle size is larger than 20 mesh, there is an advantage that the degree of expansion of graphite is large. It becomes difficult to be retained.

As a commercial item of the said thermal expansion graphite by which the neutralization process was carried out, for example, UCAR CARBON
“GRAFGUARD” 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 blending amount of the thermally expandable inorganic material used in the present invention needs to be in the range of 5 to 30% by weight based on the weight of the thermally expandable inorganic material of the present 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 inorganic 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 sinterable inorganic material used in the present invention will be described.
As a sinterable inorganic material used for this invention, an electrically insulating glass etc. can be illustrated, for example.
As the electrically insulating glass, for example, silicon dioxide is specifically 50 to 60% by weight.
Examples include E-glass containing 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. be able to.

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. As a result, the inorganic fibers contained in the thermally expandable inorganic material can be maintained in a unitary and coherent shape even after the thermally expandable inorganic material of the present invention is expanded by heat such as a fire. Even when exposed to high temperatures for a long time, the shape retention is maintained.
When the melting point is less than 650 ° C., the sinterable inorganic material and the inorganic fiber are sintered and integrated before the heat-expandable inorganic material of the present invention sufficiently expands due to heat from a fire or the like. Inferior in shape retention when exposed to high temperature for a long time, and when the melting point exceeds 1000 ° C.,
Even after the thermally expandable inorganic material of the present invention has sufficiently expanded, the sinterable inorganic material and the inorganic fiber may not be sufficiently sintered and integrated, and similarly when exposed to a high temperature for a long time. Inferior in 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. It becomes possible to lower the temperature below ℃.
Conversely, by reducing the amount of calcium oxide, magnesium oxide, etc., the proportion of covalent bonds such as silicon dioxide contained in this E glass can be increased, so that the melting point can be raised to 700 ° C. or higher. Become.

The compounding quantity of the sinterable inorganic material used for this invention needs to be 5-25 weight% on the basis of the weight of the thermally expansible inorganic material of this invention.
When the amount of the sinterable inorganic material is less than 5% by weight or more than 25% by weight, when the thermally expandable inorganic material of the present invention is exposed to a high temperature for a long time, its shape retention is reduced. To do.
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 0.
. The range is from 01 to 100 μm, preferably from 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 of winding the fiber obtained by softening and drawing the raw material of the sinterable inorganic material, the molten raw material What was obtained by methods, such as the pot method discharged | emitted from a nozzle and winding up the obtained fiber, can be obtained as a commercial item.

Moreover, when using a powder-shaped body as 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 tataacrylate-butadiene-styrene resin, ethylene-vinyl acetate resin, ethylene-propylene resin, polycarbonate resin, polyphenylene ether resin, acrylic resin, polyamide resin, polyvinyl chloride Thermoplastic resins such as 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), fluoro rubber (FKM, FZ), rubbers such as 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 needs to be 5 to 15 weight% on the basis of the weight of the thermally expansible inorganic material of this invention.
When the blending amount of the organic binder is less than 5% by weight, workability for producing the thermally expandable inorganic material of the present invention is lowered. On the other hand, when the content exceeds 15% by weight, the shape-retaining property is lowered when the thermally expandable inorganic material of the present invention 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, and an inorganic filler can be used for the thermally expandable inorganic material of the present invention as long as the object of the present invention is not impaired.

Next, a method for producing the thermally expandable inorganic material of the present invention will be described.
The method for producing the thermally expandable inorganic material of the present invention is not particularly limited and can be produced by any method. For example, a method by a papermaking method, each component of the thermally expandable inorganic material of the present invention and an organic solvent And a method of removing the organic solvent after molding the mixture.
Among these, from the viewpoint of producing a homogeneous thermally expandable inorganic material, a production method by a papermaking method is preferable.

As a manufacturing method by such a papermaking method, for example, a method by the following steps can be mentioned.
(1) Various components of the above-described thermally expandable inorganic material are dispersed in a solvent using an apparatus such as a mixer or a mill to prepare a solvent slurry of the thermally expandable inorganic material.
(2) The solvent slurry is made by a paper making machine such as a rot former and formed into a desired shape.
(3) Remove the solvent by means such as sucking, compressing, centrifuging, heating, or blowing air as necessary.
Through the above steps, the thermally expandable inorganic material of the present invention can be obtained.

The solvent preferably does not dissolve the various components of the thermally expandable inorganic material, and examples thereof include water and methanol. Among these, from the viewpoint of handleability, the solvent is preferably water.

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. Also by this method, the thermally expandable inorganic material of the present invention can be obtained.

The shape of the thermally expandable inorganic material of the present invention can be appropriately determined according to the purpose, but is usually a sheet shape.
The thickness of the thermally expandable inorganic material in the form of a sheet is usually in the range of 0.1 to 100 mm, preferably 3 to 10 mm.

The bulk density of the thermally expandable inorganic material of the present invention is usually in the range of 0.10 to 0.40 g / cm ^3, preferably ranges from 0.15~0.35g / cm ^3.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

Ceramic fibers with the compounding ratios shown in Table 1 (“SC” manufactured by Nikka Chemicals Co., Ltd.
"Bulk"), thermal expandable graphite ("GREP-EG" manufactured by Tosoh Corporation), glass fiber ("Glass chopped strand" manufactured by Asahi Fiber Glass Co., Ltd.), E glass long fiber, fiber diameter: about 10 [mu] m, fiber length: About 3mm), glass wool (Asahi Fiber Glass Co., Ltd. “
“Glasslon wool”, fiber diameter: about 4 to 7 μm), an aqueous dispersion of acrylic resin latex (“LX874” manufactured by Nippon Zeon Co., Ltd.) was prepared, and the bulk density and thickness shown in Table 1 were determined by papermaking A sheet material was prepared.
The following performance evaluation was performed about the produced thermally expansible inorganic material. 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 Examples 1 to 3, heated at 1000 ° C. for 1 h in an electric furnace, and the ratio of the expansion ratio after heating to the thickness before heating (thickness after heating / thickness before heating) Respectively.
In addition, as an index of the shape retention property of the thermally expandable inorganic material of the present invention after the heat expansion, the sample after the heating is 0.25 cm ² using a compression tester (“Finger feeling tester” manufactured by Kato Tech Co., Ltd.). The stress at break was measured at a compression rate of 0.1 cm / s with an indenter.
The results are shown in Table 1.
Note that the shape of the thermally expandable inorganic material of the present invention after thermal expansion is obtained even when a fire resistance test is performed in a state where the sample is held vertically when the stress at break of the sample is 0.05 kgf / cm ² or more. The fireproof performance can be sufficiently exhibited without breaking down.

[Example 4]
A 0.5 mm stainless steel plate was laminated on the back surface of the sample of Example 1 cut out to a 300 mm square, and a heat test for 1 hour from the front surface was performed in accordance with the method of ISO834 to measure the back surface temperature. As a result, the back surface temperature after 1 hour was 307 ° C.

[Comparative Example 1]
As a comparison, the same fire resistance test as in Example 4 was performed except that a ceramic blanket having a thickness of 30 mm was used instead of the sample in Example 4.
As a result, the back surface temperature after 1 hour was 305 ° C. Since the ceramic blanket having a thickness of 30 mm has a fire-resistant performance of 1 hour of steel frame coating, it can be seen that the thermally expandable inorganic material has the same performance.

Claims (1)

55 to 85% by weight of inorganic fiber, 5 to 30% by weight of thermally expandable inorganic substance, 5 to 1 of organic binder
A heat-expandable inorganic material comprising 5% by weight and 5-25% by weight of a sinterable inorganic material having a melting point of 650-1000 ° C.