JP2000178065A - Hardenable inorganic composition and production of inorganic molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hardenable inorganic composition having superior flowability, shapability and rapid heat hardenability, excellent in moldability and suitable for obtaining an inorganic molding that exhibits superior mechanical strength, heat resistance or the like after hardening without using a large amount of an aqueous solution of an alkali metallic silicate and to easily produce a high performance inorganic molding using the composition. SOLUTION: The hardenable inorganic composition contains (a) Al2O3-SiO2 powder, (b) an aqueous solution of an alkali metallic silicate and (c) at least one dispersing auxiliary selected from the group consisting of alcohols, glycols and ketones. The components (a) and (c) are dry-mixed, the mixture is mixed with the component (c) and the resultant hardenable inorganic composition is shaped and hardened to produce the objective inorganic molding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a curable inorganic composition suitable as a raw material for an inorganic molded article, and a method for producing an inorganic molded article using the same.

[0002]

2. Description of the Related Art Inorganic moldings are nonflammable and smokeless, and have been widely used as building materials and civil engineering materials. As such an inorganic molded article, various inorganic molded articles which are cured by heating in the presence of an alkali have been proposed.

[0003] For example, Japanese Patent Application Laid-Open No. 4-59648 discloses "15-30 parts by weight of an aqueous solution of an alkali metal silicate, 15-40 parts by weight of an inorganic solid component, and 30-70 parts by weight of a filler.
"A composition for an inorganic molded article comprising 100 parts by weight of a main material consisting of parts by weight and 5 to 20 parts by weight of an organically treated organic bentonite" has been proposed.
Japanese Patent No. 138 discloses a method for producing an inorganic molded article, comprising: kneading an aqueous alkali metal silicate solution, an inorganic solid component, and a filler, injecting the kneaded product into a mold, heating the mixture, and curing the mixture. After the curing is completed, the inorganic molded body is cooled to approximately room temperature inside or outside the mold, and the surface of the inorganic molded body in the cooled state is washed with an alkaline aqueous solution, a method for manufacturing an inorganic molded body is proposed. Have been.

However, in the case of the method using an alkali-reactive inorganic solid component as proposed in the above two proposals, fly ash and metakaolin, which are easily available among the alkali-reactive inorganic solid components, are not suitable for their powder characteristics. However, there is a drawback that it is difficult to mix with an alkali metal silicate aqueous solution, so that it is necessary to use a large amount of an alkali metal silicate aqueous solution in order to obtain a slurry having good fluidity and easy to form. As a result, the reaction rate becomes slow and it takes a long time to cure, or the mechanical strength and water resistance of the obtained inorganic molded body become insufficient, and those that satisfy the performance required as a building material or civil engineering material There is a problem that there is no.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, the present invention provides excellent fluidity, shapeability and rapid heat curability without using a large amount of an alkali metal silicate aqueous solution. A curable inorganic composition suitable for obtaining an inorganic molded article having excellent moldability and exhibiting excellent mechanical strength and water resistance after curing, and a high-performance inorganic molded article using the same. It is an object of the present invention to provide a simple production method.

[0006]

The curable inorganic composition according to the invention described in claim 1 (hereinafter referred to as "first invention") comprises the following components (a), (b) and (c): )
It is characterized by containing components. (A) Component: Al ₂ O ₃ —SiO ₂ -based powder (b) Component: Alkali metal silicate aqueous solution (c) Component: At least one dispersion selected from the group consisting of alcohols, glycols and ketones Auxiliaries

Further, the invention according to claim 2 (hereinafter referred to as “second
The present invention describes a method for producing an inorganic molded article, which comprises dry-mixing the following component (a) and the following component (c), and then shaping the curable inorganic composition obtained by mixing the following component (b). And cured. (A) Component: Al ₂ O ₃ —SiO ₂ -based powder (b) Component: Alkali metal silicate aqueous solution (c) Component: At least one dispersion selected from the group consisting of alcohols, glycols and ketones Auxiliaries

The first invention and the second invention (hereinafter referred to as "the present invention")
) Contains an Al ₂ O ₃ —SiO ₂ powder as the component (a).

The Al ₂ O ₃ —SiO ₂ based powder is not particularly limited. For example, kaolin, mullite, clay, shale, fly ash, clay, calcined sludge, slag, kaolin And one or more of these are suitably used.

The Al ₂ O ₃ —SiO ₂ based powder is
Amorphous and activated by a method of applying mechanical energy of about 0.1 to 30 kWh / kg, a method of heat treatment at a temperature of about 400 to 900 ° C., or a method of thermal spraying. Is preferred. The amorphization can be confirmed by observing a broad halo in the diffraction pattern in the X-ray diffraction method.

In the present invention, the above various Al ₂ O ₃ −
Among the SiO ₂ powders, kaolin is particularly preferably used.

Kaolin is an inorganic powder containing 50% by weight or more of kaolin mineral.
- the octahedral 1: a clay mineral consisting of 1 layered silicate, the chemical formula _{Si 2 O 5 (OH) 4} .

The kaolin mineral is not particularly limited, and examples thereof include minerals such as kaolinite, dickite, and nacrite, halloysite containing water molecules between layers of these minerals, and the like. One or more kinds are suitably used.

The kaolin used in the present invention may be, for example, a clay mineral such as mica, talc, smectite, allophane, imogolite, a silica mineral such as α-quartz, a clay such as feldspar and zeolite, in addition to the above kaolin mineral. Although it may contain minerals that are contained in the composition, the content of the kaolin mineral is preferably 50% by weight or more, more preferably 60 to 100% by weight.

If the content of kaolin mineral in kaolin is less than 50% by weight, the reactivity with alkali may be insufficient.

The curable inorganic composition according to the present invention contains an aqueous solution of an alkali metal silicate as the component (b).

The alkali metal silicate used in the alkali metal silicate aqueous solution is represented by a chemical formula of M ₂ O · nSiO ₂ . In the formula, M represents lithium, sodium or potassium, and does not include rubidium, cesium and francium.

In the formula, n represents a positive integer of 0 or 8 or less. When n exceeds 8, when mixed with water to form an aqueous solution, the viscosity sharply increases or gelation easily occurs, so that mixing with the component (a) becomes difficult, or the resulting curability The fluidity of the inorganic composition becomes poor.

The concentration of the aqueous alkali metal silicate solution is as follows:
Although not particularly limited, it is preferably 1 to 70% by weight, more preferably 30 to 60% by weight.

If the concentration of the aqueous alkali metal silicate solution is less than 1% by weight, the resulting curable inorganic composition may have poor alkali curability, whereas the concentration of the aqueous alkali metal silicate solution may be reduced to 70% by weight. If it exceeds 300, the viscosity of the curable inorganic composition obtained may be too high, and the fluidity and the shapeability may be poor.

In order to further improve the alkali curability of the curable inorganic composition, an alkali metal salt other than the alkali metal silicate may be used in the aqueous alkali metal silicate solution.

As used herein, the term "alkali metal salt" means a salt of lithium, sodium or potassium, and does not include salts of rubidium, cesium and francium.

Specific examples of the alkali metal salt are not particularly limited, but include, for example, sodium hydroxide and potassium hydroxide, and one or more of these are preferably used.

Further, in order to further improve the alkali curability of the curable inorganic composition, an aluminum salt may be used in the aqueous alkali metal silicate solution.

In an alkali metal silicate aqueous solution, aluminum
The method for dissolving the salt of
However, for example, aluminum hydroxide and the Al
_TwoO _Three-SiO_TwoSelected from the group consisting of
A machine of at least 0.1-30 kwh / kg for one kind of powder
Active inorganic powder obtained by the action of mechanical energy
Mix with the previously prepared aqueous solution of the alkali metal salt
After preparing an alkaline suspension of inorganic powder,
An alkaline suspension of powder and an aqueous solution of alkali metal silicate
Mixing method, the Al_TwoO_Three-SiO_TwoLow in system powder
At least one kind and an aqueous solution of an alkali metal silicate at room temperature to 10
Mixing and dissolving at a temperature of about 0 ° C.
Mix and dissolve at least one of the alkali metal silicate aqueous solution
Methods, etc., and any of the methods is suitably adopted.
It is.

The method of mixing the above-mentioned alkali suspension of the inorganic powder and the aqueous solution of the alkali metal silicate is not particularly limited. For example, a conventionally known stirring mixer such as a stirrer, mixer, stirrer, ball mill, blender, etc. , The two may be uniformly stirred and mixed. The mixing time at this time varies depending on the type and capacity of the stirring mixer, and is not particularly limited, but is generally preferably about 1 minute to 2 hours.

The curable inorganic composition of the present invention contains, as component (c), at least one dispersing aid selected from the group consisting of alcohols, glycols and ketones.

By including the above-mentioned dispersing aid in the curable inorganic composition, the flowability and the shapeability of the curable inorganic composition are remarkably improved, and the molding is facilitated. The mechanical strength, water resistance and the like are further improved.

The above-mentioned alcohols refer to hydroxy compounds in which a hydrogen atom of a straight-chain or alicyclic hydrocarbon is substituted with a hydroxyl group, and specific examples thereof are not particularly limited. Examples include various alcohols such as monohydric alcohols such as methyl alcohol and ethyl alcohol and polyhydric alcohols having two or more hydroxyl groups, and one or more of these are suitably used.

The above-mentioned glycols refer to dihydric alcohols, and specific examples thereof are not particularly limited, and include, for example, various glycols such as ethylene glycol and propylene glycol.
Species or two or more species are suitably used.

The above ketones are oxo compounds in which CO is bonded to two hydrocarbon groups, and specific examples thereof are not particularly limited. Examples thereof include acetone, methyl ethyl ketone, and methyl isobutyl ketone. And one or more of these are suitably used, and among them, water-soluble acetone is more preferably used.

The content of the above-mentioned dispersing aid in the curable inorganic composition is not particularly limited.
preferably to l ₂ O ₃ -SiO ₂ based powder 100 parts by weight, dispersion aids 0.05-10 parts by weight, more preferably 0.1 to 8 parts by weight.

When the content of the dispersing aid in the curable inorganic composition is less than 0.05 part by weight based on 100 parts by weight of the Al ₂ O ₃ —SiO ₂ powder, a sufficient fluidity improving effect is obtained. When the content of the dispersing agent in the curable inorganic composition exceeds 10 parts by weight based on 100 parts by weight of the Al ₂ O ₃ —SiO ₂ system powder, Water resistance and weather resistance may be reduced.

The curable inorganic composition according to the present invention includes:
If necessary, the above-mentioned components (a), (b) and (c), which are essential components, do not impair the achievement of the object of the present invention.
In addition to the ingredients, various additives such as inorganic fillers for reducing shrinkage during curing and drying, reinforcing fibers for improving mechanical strength, lightweight aggregates for reducing weight, coloring agents, defoamers, etc. One or more kinds may be contained.

Examples of the inorganic filler include, but are not particularly limited to, silica sand, silica stone powder, silica fume, mica, talc, wollastonite, calcium carbonate, and the like. The above is preferably used.

The average particle diameter of the inorganic filler is not particularly limited, but is preferably 0.01 μm to 1 mm. The average particle diameter of the inorganic filler is 0.01
If it is less than μm, the effect of reducing shrinkage during curing or drying may not be sufficiently obtained. Conversely, if the average particle diameter of the inorganic filler exceeds 1 mm, the flowability of the curable inorganic composition is impaired. As a result, the unevenness of the surface of the obtained inorganic molded article may increase.

The amount of the inorganic filler to be added is not particularly limited, but is 800 parts by weight or less of the inorganic filler based on 100 parts by weight of the alkali metal silicate aqueous solution as the component (b). And more preferably 100 to 500 parts by weight. When the amount of the inorganic filler added to 100 parts by weight of the aqueous alkali metal silicate solution is 80,
If the amount exceeds 0 parts by weight, the resulting curable inorganic composition may have insufficient alkali curability.

The reinforcing fibers are not particularly limited, but include, for example, synthetic fibers such as vinylon, polypropylene, acrylic, rayon, aramid, and acrylonitrile; glass fibers; inorganic fibers such as potassium titanate and rock wool; Fiber; steel fiber, etc., and one or more of these are suitably used.

The reinforcing fibers may be either short fibers or long fibers, or may be in the form of a mesh. When the reinforcing fiber is a short fiber, the fiber diameter is preferably, but not limited to, 1 to 500 μm, and the fiber length is preferably 1 to 15 mm. When the fiber diameter is less than 1 μm, the fibers are re-agglomerated at the time of mixing and fiber balls are easily formed by entanglement. May be impaired. If the fiber diameter exceeds 500 μm or the fiber length is less than 1 mm, a sufficient reinforcing effect may not be obtained. Conversely, if the fiber length exceeds 15 mm, dispersion in the curable inorganic composition may occur. The mixing property may be reduced, and the mechanical strength of the obtained inorganic molded product may be non-uniform.

The amount of the reinforcing fibers to be added is not particularly limited, but may be 10 parts by weight or less of the reinforcing fibers with respect to 100 parts by weight of the alkali metal silicate aqueous solution as the component (b). preferable. When the amount of the reinforcing fiber added to 100 parts by weight of the aqueous alkali metal silicate solution exceeds 10 parts by weight, the dispersibility of the reinforcing fiber may be reduced, or the heat resistance of the obtained inorganic molded article may be insufficient. .

The lightweight aggregate is not particularly limited. For example, inorganic foams such as pearlite, glass balloon, silica balloon, fly ash balloon, shirasu foam, phenolic, urethane, ethylene, Various synthetic resin foams such as styrene-based and vinylidene chloride-based are exemplified, and one or more of these are preferably used.

The specific gravity of the lightweight aggregate is not particularly limited, but is preferably 0.01 to 1. When the specific gravity of the lightweight aggregate is less than 0.01, the mechanical strength of the obtained inorganic molded article may be insufficient. On the contrary, when the specific gravity of the lightweight aggregate exceeds 1, a sufficient weight-reducing effect is obtained. May not be obtained.

The amount of the lightweight aggregate is not particularly limited. However, the amount of the lightweight aggregate is 0.1 to 100 parts by weight of the alkali metal silicate aqueous solution (b).
Preferably it is 100 parts by weight. The amount of the lightweight aggregate added to 100 parts by weight of the aqueous alkali metal silicate solution is 0.
If the amount is less than 1 part by weight, a sufficient weight-reducing effect may not be obtained. Conversely, if the amount of the lightweight aggregate exceeds 100 parts by weight with respect to 100 parts by weight of the alkali metal silicate aqueous solution, the obtained inorganic molding may be obtained. The mechanical strength of the body may be insufficient.

The method for preparing the curable inorganic composition according to the first invention is not particularly limited, and examples thereof include an omni mixer, an Erich mixer, a universal mixer, a crusher, a planetary mixer, a spiral mixer, and a pin mixer. One or two types of the essential components (a), (b) and (c), and the various additives to be contained as required, using a conventionally known stirring mixer. The desired curable inorganic composition can be obtained by uniformly stirring and mixing each of the above-mentioned predetermined amounts.
The alkali metal silicate aqueous solution as the component (b) is preferably prepared in advance.

Next, in the method for producing an inorganic molded article according to the second aspect of the present invention, the component (a) and the component (c) are first dry-mixed using the stirring mixer, and then the mixture is added to the mixture. (B) A curable inorganic composition is prepared in a procedure of mixing the components, and the obtained curable inorganic composition is shaped and cured.

When the curable inorganic composition contains solid additives such as inorganic fillers and reinforcing fibers, these solid additives are added together with the components (a) and (c). It is preferred to dry mix in advance.

By previously dry-mixing the component (a) and the other solid additives with the component (c), the dispersing aid as the component (c) becomes Al ₂ O ₃ —SiO _{2 as the} component (a).
_Since it is uniformly and satisfactorily adsorbed on the surface of the _second powder and the other solid additives, the effect of improving the fluidity and the effect of improving the shapeability by incorporating a dispersing agent become more remarkable.

The method for producing an inorganic molded article using the curable inorganic composition thus obtained is not particularly limited. For example, the method may be performed by a general molding method such as an injection method, a pressing method, an extrusion method, or the like. By shaping and curing the inorganic inorganic composition, a desired inorganic molded article can be obtained.

The curing temperature at the time of the above-mentioned curing is not particularly limited, but is preferably 1 to 300 ° C, more preferably 10 to 150 ° C. When the curing temperature is less than 1 ° C., the curing speed becomes extremely slow, and it may take a long time to cure. Conversely, when the curing temperature exceeds 300 ° C., the shrinkage during curing increases, and In some cases, cracks or the like occur in the resulting inorganic molded body, resulting in a defective product.

[0050]

The curable inorganic composition according to the first invention contains at least one dispersing aid selected from the group consisting of alcohols, glycols and ketones as an essential component, so that a large amount of alkali metal silicate is contained. It has excellent fluidity and shapeability and rapid heat curability without using an aqueous solution, and is excellent in moldability. In addition, it exhibits excellent mechanical strength and water resistance after curing, and thus is suitable as a raw material for an inorganic molded article.

The method for producing an inorganic molded article according to the second invention is characterized in that when a curable inorganic composition is produced, Al ₂ O ₃
-Since the procedure of dry-mixing the SiO ₂ -based powder and the dispersing aid in advance and then mixing the alkali metal silicate aqueous solution is employed, the dispersing aid is uniform and good on the surface of the Al ₂ O ₃ -SiO ₂ -based powder. Is adsorbed. Therefore, the obtained curable inorganic composition becomes remarkably excellent in fluidity and shapeability,
A high-performance inorganic molded article can be easily obtained with good moldability.

[0052]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the examples, “parts” means “parts by weight”, and “%” means “parts” unless otherwise specified.
It means "% by weight".

1. Were prepared Al ₂ O ₃ Prepare the following two types of Al ₂ O ₃ -SiO ₂ -based powder -SiO ₂ based powder as component (a). (1) metakaolin product name: "SP-33" (manufactured by Engelhardt Co., Ltd.), _{composition: Al 2 O 3 44%,} SiO 2 52%, other 4%,
Average particle diameter: 5 μm, specific surface area: 13 m ² / g, crystal structure: amorphous (2) Fly ash Composition: 25% Al ₂ O ₃ , 55% SiO ₂ , other 20
%, Specific surface area: 6 m ² / g, crystal structure: amorphous

2. Aluminosilicate slurry and alkali
Preparation of metal silicate aqueous solution The following two types of aluminosilicate slurries and the following two types
An aqueous alkali metal silicate solution is prepared as component (b).
Was. (1) Aluminosilicate slurry A Aluminum hydroxide (trade name "CL-
310 ", composition: Al _TwoO_Three65%, H_TwoO35%, flat
Equivalent particle size: 10 μm, manufactured by Sumitomo Chemical Co., Ltd.) 2 kg
Tora Fine Mill (Model “AT-20”, 10mmφ
Using 44 kg of luconia balls, manufactured by Mitsubishi Heavy Industries, Ltd.)
And apply mechanical energy of 5 kwh / kg to activate
Activated aluminum hydroxide powder was obtained. Next
20 parts of the activated aluminum hydroxide powder obtained above
And 100 parts of potassium hydroxide aqueous solution (48.5%)
Stir and mix uniformly using a roller to obtain an alkaline suspension.
Was. Then, 40 parts of the alkali suspension obtained above and 1 part
100 parts of K water glass (Nippon Kagaku) hand mixer
Stir and mix uniformly for 3 minutes using aluminosilicate slurry.
Lee A was prepared.

(2) Aluminosilicate slurry B As inorganic powder, kaolin (composition: 39% Al ₂ O ₃ , SiO ₂ 45) was used instead of 2 kg of aluminum hydroxide.
%, H ₂ O 14%, other 2%, average particle diameter: 5 μm,
Origin: Georgia, Sanyo Clay Co.) An activated kaolin powder was obtained in the same manner as in (1) except that 2 kg was used. Next, 48 parts of the activated kaolin powder obtained above and 100 parts of a potassium hydroxide aqueous solution (48.5%) were uniformly stirred and mixed using a stirrer to obtain an alkali suspension. Then, 49 parts of the alkali suspension obtained above and 1 part
100 parts of K water glass (manufactured by Nippon Chemical Co., Ltd.) was uniformly stirred and mixed for 3 minutes using a hand mixer to prepare an aluminosilicate slurry B.

(3) Alkali metal silicate aqueous solution I An alkali metal silicate aqueous solution I was prepared by dissolving an alkali metal silicate having a composition of 22% SiO _2, 24% K ₂ O and a molar ratio of 1.4 in water. . (4) Alkali metal silicate aqueous solution II An alkali metal silicate aqueous solution II was prepared by dissolving an alkali metal silicate having a composition of SiO ₂ 22%, Na ₂ O 24% and a molar ratio of 1.5 in water.

3. Preparation of Dispersing Aid The following three kinds of dispersing aids were prepared as component (c). (1) Ethyl alcohol (2) Ethylene glycol (3) Acetone

(Example 1)

(1) Preparation of curable inorganic composition As shown in Table 1, metakaolin 48 was used as the component (a).
Part, silica powder as inorganic filler (plain specific surface area 90
57 parts of 00 cm ² / g, manufactured by Sumitomo Cement Co., Ltd., 57 parts of wollastonite (trade name “Chemolit A-60”, manufactured by Wolkem) as an inorganic filler, and vinylon fiber (trade name “RM182”) as a reinforcing fiber. Fiber diameter 14μ
m, fiber length 6 mm, Kuraray Co., Ltd.) 1.1 parts, silica balloon (Kinseimatic Co., Ltd.) 0.0 as a lightweight aggregate
3 parts and 2 parts of ethyl alcohol as a dispersing aid as the component (c) were charged into a planetary stirring mixer and uniformly dry-mixed for 10 minutes. Next, 100 parts of the aluminosilicate slurry A was added as the component (b) to the dry mixture obtained above, and uniformly stirred and mixed for 10 minutes to prepare a curable inorganic composition.

(2) Production of Inorganic Molded Article The curable inorganic composition obtained above was poured into a mold having a width of 300 mm, a length of 3000 mm, and a thickness of 30 mm. Let it cure for a minute,
An inorganic molded body was manufactured.

(3) Evaluation The flow value of the curable inorganic composition obtained above, and the bending strength and the bending strength maintenance rate after boiling of the obtained inorganic molded article were evaluated by the following methods. The results were as shown in Table 1.

Flow value: The spread area flow value (cm ² ) of the curable inorganic composition 5 minutes after the preparation was measured using a table flow tester in accordance with JIS R-5201.

Flexural strength: 50 parts of the demolded inorganic molded body
After drying at 24 ° C. for 24 hours, the bending strength (kgf / cm ² ) was measured in accordance with JISA-1408.

Bending strength retention after boiling: The demolded inorganic molded body was immersed in boiling water for 8 hours, and then taken out.
After drying at 50 ° C. for 24 hours, the bending strength was measured in the same manner as in the above case, and the bending strength maintenance ratio (%) was calculated by the following equation. Bending strength maintenance rate (%) = (Bending strength after boiling /
Flexural strength before boiling) x 100

(Examples 2 to 4, and Comparative Examples 1 and 2)
Five kinds of curable inorganic compositions were obtained in the same manner as in Example 1 except that the curable inorganic composition was changed to the compounding composition shown in Table 1.

The flow values of the five types of curable inorganic compositions obtained above were evaluated in the same manner as in Example 1. The results were as shown in Table 1.

Next, using the five types of curable inorganic compositions obtained above, an inorganic molded article was produced in the same manner as in Example 1. However, since the curable inorganic composition of Comparative Example 1 had a low flow value and poor fluidity,
The production of the inorganic molded article could not be performed. Therefore, there were four types of the obtained inorganic molded bodies.

The bending strength and the bending strength maintenance rate after boiling of the four types of inorganic molded articles obtained above were evaluated in the same manner as in Example 1. The results were as shown in Table 1.

(Comparative Example 3) The curable inorganic composition was made to have the composition shown in Table 1, and the components (a) and other solid components were not dry-mixed with the dispersing aid (component (c)). After mixing the component (a), the inorganic filler and the reinforcing fiber,
A curable inorganic composition was obtained in the same manner as in Example 1 except that the component (b) was mixed, and finally, the lightweight aggregate and the dispersing aid as the component (c) were mixed.

Next, using the curable inorganic composition obtained above, an inorganic molded article was produced in the same manner as in Example 1.

The flow value of the curable inorganic composition obtained above, and the bending strength and the bending strength maintenance rate after boiling of the obtained inorganic molded article were evaluated in the same manner as in Example 1. . The results were as shown in Table 1.

[0072]

[Table 1]

As is clear from Table 1, the curable inorganic compositions of Examples 1 to 4 according to the present invention have high flow values,
Excellent fluidity was shown. In addition, the inorganic molded products of Examples 1 to 4 produced using the curable inorganic composition described above exhibited both high flexural strength and high flexural strength retention after boiling, and exhibited excellent physical properties.

On the other hand, the curable inorganic composition of Comparative Example 1, which did not contain a dispersing aid, had a low flow value and poor fluidity, so that an inorganic molded article could not be produced.

The inorganic molded article of Comparative Example 2, which was produced using the curable inorganic composition of Comparative Example 2 which contained a large amount of an aqueous alkali metal silicate solution without containing a dispersing aid, had a flexural strength. And the bending strength maintenance rate after boiling was extremely low.

Furthermore, Comparative Example 3 produced using the curable inorganic composition of Comparative Example 3 in which the dry mixing of the component (a) and other solid components with the dispersing aid as the component (c) was not performed. The inorganic molded article of Example 1 had a low bending strength and a low bending strength maintenance rate after boiling.

[0077]

As described above, the curable inorganic composition according to the present invention has excellent fluidity and shapeability and rapid heat curability, and is excellent in moldability. In addition, it exhibits excellent mechanical strength and water resistance after curing, and is suitable for obtaining a high-performance inorganic molded article.

Further, according to the production method of the present invention, a high-performance inorganic molded article which can withstand use under severe conditions can be easily obtained.

Claims (2)

[Claims] 1. A curable inorganic composition comprising the following components (a), (b) and (c). (A) Component: Al ₂ O ₃ —SiO ₂ -based powder (b) Component: Alkali metal silicate aqueous solution (c) Component: At least one dispersion selected from the group consisting of alcohols, glycols and ketones Auxiliaries 2. A curable inorganic composition obtained by dry-mixing the following component (a) and the following component (c) and then mixing the following component (b), followed by curing. A method for producing an inorganic molded article. (A) Component: Al ₂ O ₃ —SiO ₂ -based powder (b) Component: Alkali metal silicate aqueous solution (c) Component: At least one dispersion selected from the group consisting of alcohols, glycols and ketones Auxiliaries