JPH1025174A - Composition for ceramic foam and ceramic foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition for a ceramic foam capable of providing a ceramic foam having an improved strength, heat insulating properties and thermal stability by blending specific two kinds of granules, a foaming agent and a water glass. SOLUTION: This composition is obtained by kneading the first granules comprising SiO2 , CaO, an iron oxide, a titanium oxide and aluminum hydroxide, the second granules which are an admixture, and a foaming agent and a water glass. Concretely, the first granules are obtained by mixing 30-50wt.% slag containing the >=15wt.% SiO2 , the >=25wt.% CaO, the <=5wt.% iron oxide and the >=0.2wt.% titanium oxide with the 30-50wt.% silica powder having 0.1-1μm particle diameter and the 10-30wt.% aluminum hydroxide having 0.5-20μm particle diameter. The objective composition for a ceramic foam is obtained by blending the 30-50wt.% first granules with the 30-50wt.% second granules comprising a fly ash having >=2wt.% content of carbon, a foaming agent, the 10-30wt.% water glass and optionally 30-50wt.% lightweight aggregate. The ceramic foam having <=1g/cm<3> specific gravity, <=9×10<-5> cal/cm.sec.deg thermal conductivity, >=300kgf/mm<2> compression strength and >=10kgf/mm<2> Brinell hardness is obtained by foaming and hardening the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic foam, and more particularly to a ceramic foam useful as, for example, a heat-resistant coating for high-strength concrete or a steel frame, and a composition for the ceramic foam for obtaining the same.

[0002]

^2. Description of the Related Art Although concrete having a general composition has a compressive strength of 500 to 600 kgf / cm ² , a high-strength concrete having a compressive strength exceeding 1000 kgf / cm ² can be obtained by devising the composition. By using such high-strength concrete, a high-rise building mainly composed of concrete can be realized. However, high-strength concrete has a problem in heat resistance. In other words, high-strength concrete has a high strength, so the steam generated inside when it is subjected to strong heat due to a fire or the like is confined, causing a high pressure state, and this high-pressure steam explosively destroys concrete, that is, Easy to explode.
Due to the explosion problem, high-strength concrete cannot be used as a general-purpose structural material while having excellent strength characteristics.

[0003]

Against this background, the inventor of the present application has conducted research on improving the heat resistance of high-strength concrete, and in particular, has high heat insulation properties and excellent bondability with concrete. Research has been conducted to improve heat resistance by covering the surface of high-strength concrete with a heat-resistant coating layer. The obtained invention is intended to provide a ceramic foam which can be used as an effective heat-resistant coating for high-strength concrete and a composition for obtaining the same.

[0004]

The composition for ceramic foam according to the present invention comprises silicon dioxide (SiO ₂ ), calcium oxide.
(CaO), iron oxide _{(FeO, Fe 2 O 3)} , titanium oxide (TiO, TiO ₂₎
And a first powder containing at least aluminum hydroxide (Al (OH) ₃ ), a second powder as a contaminant, and a foaming agent are kneaded with water glass.

[0005] The ceramic foam obtained by foaming and curing such a composition for ceramic foam is a ceramic system similar to concrete, and therefore has excellent bonding strength to concrete and can be substantially integrated. it can. Also, this ceramic foam has high heat resistance,
No abnormality is observed in the heat resistance test at 1050 ° C. for 3 hours. In addition, the specific gravity is as light as 1 g / cm ³ or less, the thermal conductivity is 9 × 10 ⁻⁵ cal / cm.sec.deg or less, and it has high heat insulation. Furthermore, the compressive strength is 300kgf / mm
^{It is 2} or more, and has a Brinell hardness of 10 kgf / mm ² or more, and is excellent in strength.

Further, the composition for ceramic foam according to the present invention can be foamed and cured at room temperature to give a ceramic foam exhibiting the above-mentioned properties. Therefore, only by applying this, a ceramic foam layer serving as a high-performance heat-resistant coating can be formed on the surface of columns or beams made of high-strength concrete.

As described above, the composition for a ceramic foam according to the present invention has excellent suitability as a heat-resistant coating for high-strength concrete, but is also highly useful as a heat-resistant coating for steel frames and the like. That is, the ceramic foam obtained by the composition for a ceramic foam according to the present invention,
It is light, has high heat insulating properties, has high strength, and has a sufficiently large adhesive force to iron materials as compared with conventional heat-resistant coating materials for steel frames, and has excellent suitability for heat-resistant coatings on steel frames and the like. Further, the ceramic foam according to the present invention can be used alone as a heat insulating material having excellent strength or a board material utilizing high heat insulating properties.

It is preferable to use aluminum powder as the blowing agent in the composition for ceramic foam as described above. In addition, the first powder in the composition for ceramic foam as described above contains 15% by weight or more of silicon dioxide, 25% by weight or more.
More than 5% by weight of calcium oxide, more than 5% by weight of iron oxide,
Slag containing at least 0.2% by weight or more of titanium oxide and having a particle size of 120 μm or less;
Of silica powder and aluminum hydroxide having a particle size of 0.5 to 20 .mu.m in a ratio of 30 to 50% by weight of slag, 30 to 50% by weight of silicon dioxide and 10 to 30% by weight of aluminum hydroxide. Is most preferred. The slag composition described above is generally satisfied by slag generated in electric furnace steelmaking. Therefore, it is preferable to use electric furnace steelmaking slag as the slag.

On the other hand, it is particularly preferable to use fly ash for the second powdery granule which is an aggregate-like mixed material. As the fly ash, fly ash having a carbon content of 2% by weight or more is particularly preferable, and the carbon contained in the fly ash can promote the foaming reaction of aluminum.

In the composition for a ceramic foam as described above, the mixing ratio of the first and second powders and the water glass is 30 to 50% by weight of the first powder and the second powder. 30 to 50% by weight of powder and 10 to 3 of water glass
The content of 0% by weight is particularly preferable for exhibiting the above-mentioned characteristics.

Further, with respect to the composition for a ceramic foam as described above, a lightweight aggregate such as a ceramic foam granule can be further added as a third powder. By adding the lightweight aggregate in this manner, a large heat insulating property can be obtained even at a low expansion ratio.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the first embodiment of the present invention, slag from electric furnace steelmaking (for example, product name "Datong slag" of Daido Special Steel Co., Ltd.) is used as slag in the first granular material.
The component composition of this slag is as follows. Composition of electric furnace steelmaking slag (% by weight) Silicon dioxide (SiO ₂ ) 20.56 Calcium oxide (CaO) 32.83 Total iron 13.67 Magnesium oxide (MgO) 9.28 Aluminum oxide (Al ₂ O ₃ ) 8.66 Manganese oxide (MnO) 4.21 All chrome (Cr) content 1.50 Titanium oxide (TiO ₂ ) 0.46 Other 8.83

The composition of the first granular material using the above slag is as follows. Electric furnace steelmaking slag 40 having a particle size of 97 μm or less (silica fume (SiO ₂ ) 40 having a particle size of 97 μm or less) Aluminum hydroxide (Al) having a particle size of 1 to 10 μm (OH) ₃ ) 20

As the second powder, fly ash having a particle diameter of 20 μm or less is used. And water glass is K ₂ O; 24
Wt%, SiO _2: 21.4 wt%, water; 53.3% by weight of water or glass potassium system which is a component configuration, or Na ₂ O; 17.9 wt%, SiO _2: 25.9 wt%, water; 53.6% by weight of component A sodium-based water glass having a configuration is used. In addition, lithium-based water glass can be used, but lithium-based water glass is generally expensive and impractical.

These first and second powders and aluminum powder as a foaming agent are kneaded with water glass in the following ratio (% by weight), and the kneaded material is applied to a high-strength concrete molded product. By allowing the foam to harden for about three times by allowing it to stand for a time, a ceramic foam having a thickness of 10 mm was formed as a heat-resistant coating layer integrally attached to the high-strength concrete molding. First granular material 39.9 Second granular material 39.9 Aluminum powder 0.2 Water glass 20.0

The thus obtained ceramic foam was dried at 150 ° C. for 3 hours for rapid drying, and then its physical properties were measured. The results are as follows. Specific gravity (g / cm ² ) 0.80 Compressive strength (kgf / mm ² ) 300 Brinell hardness (kgf / mm ² ) 11 Water absorption (immersed in 20 ° C. water for 72 hours) (g) 0.0002 Heat resistance (1050 ° C. 3 hours) Abnormal None

In the second embodiment of the present invention, a third powder is added in addition to the first and second powders as in the first embodiment. As the third powder, a mineral-based granular foam (for example, “G-light” manufactured by Sunlight Co., Ltd.) is used. This third powder has a particle size of
It is 0.3 to 1.2 mm and has a bulk specific gravity of 0.31 to 0.47 (Kg / l).
The composition (% by weight) in the present embodiment is as follows. First granular material 23.9 Second granular material 28.9 Third granular material 32.0 Aluminum powder 0.2 Water glass 20.0

The physical properties of the ceramic foam according to the second embodiment are as follows. Specific gravity (g / cm ² ) 0.7 Compressive strength (kgf / mm ² ) 250 Brinell hardness (kgf / mm ² ) 8 Water absorption (immersed in water at 20 ° C for 72 hours) (g) 0.0005 Heat resistance (1050 ° C for 3 hours) Abnormal None

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[Procedure amendment]

[Submission date] January 8, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction contents]

The thus obtained ceramic foam was dried at 150 ° C. for 3 hours for rapid drying, and then its physical properties were measured. The results are as follows. Specific gravity 0.80 Compressive strength (kgf / cm ² ) 300 Brinell hardness (kgf / mm ² ) 11 Water absorption rate (immersed in water at 20 ° C for 72 hours) (g) 0.0002 Heat resistance (1050 ° C for 3 hours) No abnormality

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction contents]

The physical properties of the ceramic foam according to the second embodiment are as follows. Specific gravity 0.7 Compressive strength (kgf / cm ² ) 250 Brinell hardness (kgf / mm ² ) 8 Water absorption (immersed in water at 20 ° C for 72 hours) (g) 0.0005 Heat resistance (1050 ° C for 3 hours) No abnormality

Claims (8)

[Claims] 1. Silicon dioxide, calcium oxide, iron oxide,
A composition for a ceramic foam obtained by kneading a first granule containing at least titanium oxide and aluminum hydroxide, a second granule as a mixing material, and a foaming agent into water glass. 2. A particle having at least 15% by weight or more of silicon dioxide, 25% by weight or more of calcium oxide, 5% by weight or more of iron oxide, and 0.2% by weight or more of titanium oxide. Slag having a particle size of 120 μm or less;
A mixture of silica powder of 1 to 1 μm and aluminum hydroxide having a particle size of 0.5 to 20 μm, wherein slag is 3 μm.
The composition for a ceramic foam according to claim 1, wherein the composition comprises 0 to 50% by weight, 30 to 50% by weight of a silica powder, and 10 to 30% by weight of an aluminum hydroxide. 3. The composition for a ceramic foam according to claim 1, wherein the second granular material is fly ash. 4. The composition for a ceramic foam according to claim 3, wherein fly ash having a carbon content of 2% by weight or more is used. 5. The method according to claim 1, wherein the first granular material is 30 to 50% by weight,
The composition for a ceramic foam according to any one of claims 1 to 4, wherein the composition is such that the powdery granule is 30 to 50% by weight and the water glass is 10 to 30% by weight. 6. The composition for a ceramic foam according to claim 1, further comprising a third granular material which is a lightweight aggregate. 7. The composition for a ceramic foam according to claim 6, wherein the proportion of the third powder is 30 to 50% by weight based on the first and second powders. 8. A ceramic foam obtained by foaming and curing the composition for a ceramic foam according to any one of claims 1 to 7.