JPH09300318A - Manufacture of inorganic laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacture of an inorganic laminate wherein a molded product which is light weighted and excellent in mechanical strength, incombustibility and appearance can be obtained and heat treatment is not required prior to forming a formed layer. SOLUTION: The laminate is prepared by laminating an elaborate layer and a foamed layer. Then, a manufacturing method is composed of a process wherein a slurry composed of SiO2 -Al2 O3 powdery material, alkali material silicate, and water is powred into a form, and pressed with a presser to form the elaborate layer, a process wherein a slurry composed of SiO2 -Al2 O3 powdery material, alkali metal silicate, water, and at least one kind of foaming agent and frother is poured onto the elaborate layer in the form, and hardened by heated while foaming to form the foamed layer, and a process wherein the slurry composed of SiO2 -Al2 O3 powdery material, alkali metal silicate, and water is poured onto the foamed layer in the form, the whole is completely hardened by heating to form a laminate, and the mold is released.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an inorganic laminate which is lightweight and has excellent nonflammability, mechanical strength, durability and appearance.

[0002]

_2. Description of the Related Art A cured product made of a mixture containing SiO ₂ -Al ₂ O ₃ powder and an alkali metal silicate as a main component is excellent in nonflammability and mechanical strength. It has been proposed as a building material such as interior and exterior wall materials for buildings, partitions, roof tiles, floors, etc.

Japanese Patent Publication No. 3-9060 discloses an inorganic hardened material obtained by mixing an electrostatic precipitator ash or calcined bauxite with an aqueous solution of an alkali metal silicate and curing the mixture by heating.
However, this inorganic cured product has a high specific gravity and has a problem in workability when used as a building material.

Japanese Unexamined Patent Publication No. 3-103378 discloses Si
Disclosed is an inorganic foamed and cured product obtained by mixing an O ₂ —Al ₂ O ₃ -based powder and an aqueous solution of an alkali metal silicate with a foaming agent or a foaming agent and curing the mixture by heating. Such an inorganic foamed cured product has a high utility value in that it is lightweight, but has a problem that it breaks during transportation or construction due to its low strength.

Further, Japanese Laid-Open Patent Publication No. 7-304142 discloses a laminate of a cured product and a foam. However, when the slurry for forming the first layer, which is a dense layer, has high fluidity when manufacturing such a laminated body, it is semi-cured until the slurry for forming the second layer, which is the foamed layer, is poured. Heat treatment is required to
When the fluidity of the slurry of the first layer is low, there is a drawback that the conformability of the mold surface shape is poor. Furthermore, when such a laminate is cast-molded, the bubbles taken into the slurry come into contact with the mold surface so that all the bubbles do not float on the surface of the slurry and remain on the surface of the slurry. However, there is a problem that the appearance is impaired and the surface hardness is partially uneven.

[0006]

In view of the above situation, the present invention can provide a molded product which is lightweight and has excellent mechanical strength, nonflammability and appearance, and further requires heat treatment before forming a foam layer. It is an object of the present invention to provide a method for producing an inorganic laminate which does not satisfy the requirements.

[0007]

Means for Solving the Problems The method for producing an inorganic laminate comprising a dense layer and a foam layer of the present invention is SiO.
_2- Al ₂ O ₃ -based powder, alkali metal silicate, and
A step of forming a dense layer by pouring a slurry made of water into a mold and pressing it with a press molding machine, S
iO ₂ -Al ₂ O ₃ system powder, alkali metal silicate,
Pouring water and a slurry comprising at least one of a foaming agent and a foaming agent onto the dense layer in the mold,
A step of forming a foam layer by performing heat curing treatment while foaming, and a slurry of SiO ₂ —Al ₂ O ₃ -based powder, an alkali metal silicate, and water is added to the foam layer in the mold. It is characterized in that it comprises a step of forming a laminated body by completely heating and curing the whole body after pouring it on top and demolding. Hereinafter, the present invention will be described in detail.

In the manufacturing method of the present invention, as a first step, first, a dense layer is formed. The dense layer is obtained by placing a mold in a mold, pouring a slurry containing SiO ₂ —Al ₂ O ₃ based powder, an alkali metal silicate and water as the main components into the mold and pressing it with a press molding machine. To be formed.

As the above-mentioned SiO ₂ —Al ₂ O ₃ powder, SiO ₂ —Al ₂ O ₃ = 1/9 to 9/1 (weight ratio)
Can be used, as a whole, SiO ₂ and Al ₂ O ₃
It is preferable that the total amount of these components is 50% by weight or more. If the content is less than 50% by weight, the reactivity with the alkali metal silicate aqueous solution is lowered, and the strength of the obtained molded article is lowered.

Examples of the SiO ₂ -Al ₂ O ₃ based powder include (1) fly ash containing 80% by weight or more of particles having a particle size of 10 μm or less (2) fired at 400 to 1000 ° C. and 10 μm Fly ash containing 80% by weight or more of the following particle sizes (3) Fly ash, an inorganic powder obtained by melting clay and spraying it into gas (4) 0.1 to 30 kwh / kg of clay Inorganic powder obtained by applying mechanical energy (5) Inorganic powder obtained by heating powder of (4) at 100 to 750 ° C. (6) Metakaolin with 0.1 to 30 kwh / kg Inorganic powder obtained by applying mechanical energy (7) Ash of an electrostatic precipitator during corundum or mullite production (8) Ground calcined bauxite (9) Metakaolin Is, (1) to at least one or more powders selected from the group consisting of (9) can be used.

Generally, fly ash refers to JIS A.
6201 is a fine ash particle collected by a dust collector from a pulverized coal combustion boiler, which is SiO ₂ 40%.
Above, moisture 1% or less, specific gravity 1.95 or more, specific surface area 27
It passes at least 75% through a standard sieve of at least 00 cm ² / g and 44 μm. As a method for obtaining the fly ash of the above (1), any conventionally known method is adopted, for example, a method using a classifier that is commonly used such as wet sedimentation classification, air classification, separation by specific gravity; jet mill, Examples include a method using a fine pulverizer such as a roll mill and a ball mill, and a continuous system of a classifier and a pulverizer can also be used.

If the amount of the fly ash having a particle size of 10 μm or less is less than 80% by weight, the reactivity with the alkali metal silicate aqueous solution is lowered, resulting in a decrease in strength or a curing failure, which is not preferable.

The fly ash of the above (2) is obtained by firing the fly ash of the above (1) at 400 to 1000 ° C., or the fly ash fired at 400 to 1000 ° C. in the same manner as in the above (1), 10 μm. A fly ash containing 80% by weight or more of the following particle size is obtained.

The fly ash is usually black, but when coloring is required, it is decolorized by firing. The above decolorization is possible at 400 ° C. or higher, but if calcined at a temperature higher than 1000 ° C., the reactivity with the alkali metal silicate aqueous solution is lowered, so it is preferable to calcinate at the above temperature range.

The above-mentioned inorganic powder (3) is obtained by melting fly ash and clay and spraying them into gas.
O ₂ —Al ₂ O ₃ -based powder can be obtained, but as a method of melting and spraying in a gas, a thermal spraying method used for ceramic coating or the like is adopted. Examples of the thermal spraying method include a plasma thermal spraying method, a high energy gas thermal spraying method, and an arc thermal spraying method. The melting temperature of the fly ash and clay during the thermal spray treatment is 200
It is preferable that the spraying speed is 0 to 16000 ° C. and the spraying speed is 30 to 80 m / s. Further, the specific surface area of the reactive inorganic powder activated by the thermal spraying treatment is 0.1
-60 m < ² > / g is preferable.

The clay in the above (3) and (4) has a chemical composition of SiO ₂ : 5 to 85% by weight, Al ₂
Clay containing O ₃ : 90 to 10 wt% is used, and examples thereof include kaolin minerals such as kaolinite, dickite, nacrite and halloysite,
Mica clay minerals such as muscovite, illite, phengite, glauconite, celadonite, paragonite, blancmalite, smectites such as montmorillonite, beidellite, nontronite, savonite, sauconite, chlorite, virophyllite, talc, banc. Examples include soil shale.

A reactive inorganic powder can be obtained by applying mechanical energy of 0.1 to 30 kwh / kg to the clay and metakaolin of (4), (5) and (6). The mechanical energy refers to a compressive force, a shearing force, and an impact force, and these may be used alone or in combination. The method of applying the mechanical energy is not particularly limited, and examples thereof include a ball mill, a vibration mill, a planetary mill, a medium agitation type mill, a roller mill, a mortar, and a jet pulverizing device.

The mechanical energy is 0.1 to 30 k.
wh / kg is preferable, and more preferably 1.0 to 26k
wh / kg. If it is less than 0.1 kwh / kg,
The reactivity with the alkali metal silicate aqueous solution decreases,
If it exceeds kwh / kg, the load on the crushing device increases, the wear and damage of the device increase, and problems such as impurities in the clay occur. The particle diameters of the clay and metakaolin of (4), (5) and (6) are not particularly limited, but an average particle diameter of 0.01 to 500 μm is preferable in order to effectively apply mechanical energy, and It is preferably 0.1 to 100 μm.

When the above mechanical energy is applied, a grinding aid may be added if necessary. The grinding aid prevents adhesion of the clay and metakaolin powder to the inside of the apparatus and remarkable aggregation when the mechanical energy is applied. For example, alcohols such as methyl alcohol and ethyl alcohol; triethanolamine. And alcohol amines; metal soaps such as sodium stearate and calcium stearate; and acetone vapor. These may be used alone or in combination of two or more.

The inorganic powder of the above (5) is further heated at 100 to 750 ° C. after the mechanical energy is applied to the clay.
It can be obtained by heating to 1, because the improvement of mechanical strength is recognized by heating. If the heating temperature is less than 100 ° C., no improvement in strength will be observed, and if it exceeds 750 ° C., crystallization of the inorganic powder occurs and the reactivity with the alkali metal silicate aqueous solution decreases. Preferably 20
0-600 ° C. The heating time is preferably 1 minute to 5 hours. When the time is less than 1 minute, the mechanical strength of the obtained cured product is not improved much, and when it exceeds 5 hours, the energy cost increases.

The inorganic powders of the above (7) and (8) are the same as those disclosed in Japanese Examined Patent Publication No. 3-9060 and Japanese Examined Patent Publication No. 4-45471.
It is a powder as described in the publication. Commercially available metakaolin can be used as the inorganic powder of (9).

The alkali metal silicate used in the present invention has a general formula: M ₂ O.nSiO ₂ (where M is
It represents at least one selected from the group consisting of K, Na and Li. n represents a positive rational number. ). Among these, those in which n is 0.05 to 8 are preferable. If it is less than 0.05, a cured product having a good appearance cannot be obtained, and if it exceeds 8, gelation tends to occur, the viscosity of the aqueous solution increases, and mixing becomes difficult. More preferably 0.5
~ 2.5.

The alkali metal silicate is preferably added as an aqueous solution. As the concentration of the above aqueous solution,
Although not particularly limited, it is preferably 10 to 60% by weight. 1
If it is less than 0% by weight, the reactivity with the above-mentioned SiO ₂ —Al ₂ O ₃ powder is lowered, and if it exceeds 60% by weight, an alkali metal salt is likely to be produced. The aqueous solution may be prepared by dissolving the alkali metal silicate as it is in water under pressure and heating, and adding the SiO ₂ component such as silica sand and silica stone powder to the alkali metal hydroxide aqueous solution as described above. It may be prepared by dissolving under pressure and heating so that n in the formula becomes a predetermined amount.

The content of the alkali metal silicate is S
10 to 10 parts by weight of io ₂ -Al ₂ O ₃ based powder
80 parts by weight are preferred. If the blending amount is too small, curing will not be sufficient, and if the blending amount is too large, the water resistance of the resulting laminate will be reduced. Further, when the blending amount is large, the fluidity of the obtained slurry becomes too large, which makes it difficult to press thereafter, and the effect of the present invention that heating is not required cannot be obtained. It is more preferably 20 to 70 parts by weight.

The above-mentioned water may be added in the form of an aqueous solution of alkali metal silicate in the total amount, or may be added in the form of both an aqueous solution of alkali metal silicate and independent water. The amount of water added is preferably 10 to 1000 parts by weight based on 100 parts by weight of SiO ₂ —Al ₂ O ₃ -based powder. If the amount is less than 10 parts by weight, sufficient curing will not occur and 1
If it exceeds 000 parts by weight, the strength of the cured product will decrease. More preferably 10 to 750 parts by weight, further preferably 5
0 to 500 parts by weight.

To form a slurry for forming the dense layer of the present invention, these mixtures are mixed with JIS A 110.
In the slump test according to the regulations of 1, the value is 50 to 25
It is preferable to adjust the viscosity to 0 mm. Within this range, heat treatment for curing this layer becomes unnecessary.

In the first step, when the inorganic laminate of the present invention has a deep uneven pattern as an outer layer, as will be described in detail later, when pouring the slurry, the convex portions of the mold after pressing, which will be described later, are performed. It is necessary to use a sufficient amount so that the height is higher than the surface. If the amount of the slurry is too small, when the inorganic laminate of the present invention is molded, the bubbles of the foam layer appear on the surface of the laminate as foam breaks in contact with the mold surface, impairing the appearance and reducing the expected appearance. Can't get

In the present invention, after the above slurry is poured into a mold, the slurry is set in a press machine and pressed. The pressing method is not particularly limited, and roll pressing or the like can be used.

The pressing pressure of the above-mentioned press is 10 to
30 kg / cm ² is preferred. If it exceeds 30 kg / cm ² , stress will be accumulated inside and cracks will occur in the laminate during the final curing treatment. On the other hand, if it is less than 10 kg / cm ² , problems such as insufficient molding and poor followability of the mold surface shape occur.

In the second step of the present invention, a foam layer is formed on the dense layer. The foam layer is formed by applying SiO ₂ —Al ₂ O on the dense layer in the mold after the pressing.
It is formed by pouring a slurry of ₃ type powder, an alkali metal silicate, water, and at least one of a foaming agent and a foaming agent, and performing heat curing treatment while foaming.

The foaming agent is not particularly limited, and examples thereof include Mg, Ca, Cr, Mn, Fe, Co, Ni and C.
Examples thereof include metal powders such as u, Zn, Al, Ga, Sn, Si, and ferrosilicon; peroxide powders such as hydrogen peroxide solution, sodium peroxide, potassium peroxide, and sodium perborate.

The particle size of the above-mentioned peroxide powder is 1 to 200.
μm is preferred. When it is less than 1 μm, the dispersibility is lowered and the foaming is rapidly performed, and when it exceeds 200 μm, the reactivity is lowered. As the above-mentioned foaming agent, from the viewpoint of cost, safety, easy availability and easy mixing, A
It is preferable to use hydrogen peroxide solution. The blending amount of the foaming agent is preferably 5 parts by weight or less with respect to 100 parts by weight of SiO ₂ —Al ₂ O ₃ -based powder. When it exceeds 5 parts by weight, the strength is remarkably lowered, and the molded product cannot be handled.

The foaming agent is not particularly limited, and examples thereof include higher alcohol sulfate ester salt, alkyl ether sulfate ester salt, aromatic derivative sulfonate, imidazoline derivative, fatty acid amide, and animal protein. The blending amount of the foaming agent is preferably 10 parts by weight or less based on 100 parts by weight of the SiO ₂ —Al ₂ O ₃ based powder.
If it exceeds 10 parts by weight, poor curing will occur.

The slurry is heat-treated in an atmosphere of 50 to 100 ° C. to be hardened to form a foam layer. The heat treatment is not particularly limited, and can be performed, for example, in an oven.

In the third step of the present invention, SiO ₂
After pouring a slurry composed of —Al ₂ O ₃ -based powder, an alkali metal silicate, and water onto the foam layer in the mold, the whole is completely heat-cured to form a laminate, Remove the mold. The same slurry as that used in the above-mentioned first step can be used as the above-mentioned slurry.

The above complete heat curing can be carried out in an atmosphere of 50 to 100 ° C. The heating time is 1 to 15
Time is appropriate. The heating method is not particularly limited, and examples thereof include an oven.

In the present invention, the inorganic laminate of the present invention is obtained by taking out the molded product from the mold after forming the laminate by the above-mentioned complete heating and curing.

In the present invention, inorganic fillers, reinforcing fibers, lightweight aggregates, pigments, foaming aids, etc. may be added to the above-mentioned slurries for producing the above-mentioned inorganic laminate as necessary as other raw materials. Can be used.

The above-mentioned inorganic filler is not particularly limited as long as it has a low activity against an alkali metal silicate aqueous solution, and examples thereof include silica sand, rock powder, volcanic ash (shirasu, anti-firestone, etc.), wollastonite, calcium carbonate, Examples thereof include silica stone powder, diatomaceous earth, mica, mica, and silica fume. The reason why the activity of the inorganic filler with respect to the alkali metal silicate aqueous solution is desired to be low is that when the activity is high, the gelation of the alkali metal silicate aqueous solution proceeds rapidly, which makes mixing and molding difficult. is there. The addition amount of the inorganic filler is
It is preferably 900 parts by weight or less based on 100 parts by weight of the powder. If it exceeds 900 parts by weight, the mechanical strength of the inorganic laminate decreases.

As the reinforcing fibers, reinforcing fibers used in ordinary cement products can be used. Examples thereof include polypropylene fiber, vinylon fiber, rayon fiber, alkali resistant glass fiber, carbon fiber, acrylic fiber, aramid fiber and acrylonitrile fiber. These may be used alone or in combination. The fiber diameter of the reinforcing fiber is 1 to 5
00 μm is preferred. When it is less than 1 μm, a fiber ball is easily formed when the above-mentioned inorganic powder is mixed, and the strength is liable to be lowered. The fiber length of the reinforcing fiber is preferably 1 to 15 mm. If it is less than 1 mm, the reinforcing effect such as improvement in tensile strength is small, and it is 15 m.
When it exceeds m, the dispersibility and orientation of the fiber are deteriorated, and a cured product having uniform strength cannot be obtained. The content of the reinforcing fibers is preferably 10 parts by weight or less with respect to 100 parts by weight of SiO ₂ —Al ₂ O ₃ -based powder. If it exceeds 10 parts by weight, the dispersibility of the fiber will be reduced.

Examples of the above lightweight aggregates include inorganic foams such as pearlite, glass balloons, silica balloons, fly ash balloons, and shirasu foams; organic foams such as phenolic resins, urethane resins, polyethylene and polystyrene. To be The blending amount of the above lightweight aggregate is 100 parts by weight of SiO ₂ —Al ₂ O ₃ -based powder,
It is preferably 150 parts by weight or less. If it exceeds 150 parts by weight, the strength is lowered, the surface smoothness is lowered, and the molding workability is lowered.

Examples of the above pigments include metal oxide pigments such as iron oxide, titanium oxide, cobalt oxide and chromium oxide, and carbon black. The blending amount of the above pigment is preferably 50 parts by weight or less with respect to 100 parts by weight of the SiO ₂ —Al ₂ O ₃ based powder. Even if added in excess of 50 parts by weight, the hiding power does not improve and it is uneconomical.

Examples of the foaming aid include porous powder such as silica gel, zeolite, activated carbon and alumina gel; metal soap such as metal salt of stearic acid and metal salt of palmitic acid. The blending amount of the foaming aid is SiO ₂ —Al ₂
It is preferably 10 parts by weight or less with respect to 100 parts by weight of O ₃ based powder. If it exceeds 10 parts by weight, foam breakage or the like is caused to adversely affect foaming.

According to the production method of the present invention, since the dense layer can be used as the outer layer, even an inorganic laminate having a deep uneven pattern on the surface can be produced, and the inorganic laminate has a high decorative property. It is useful as a body, for example, for building exteriors. According to the production method of the present invention, since the intermediate layer can be a foam layer, it is possible to provide an inorganic laminate that is lightweight and has excellent workability. Further, if the dense layer sandwiches the foamed layer, it can be used as a laminate of three or more layers.

[0045]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the method for producing an inorganic laminate of the present invention will be described below with reference to the drawings. FIG. 1 shows the process of forming the dense layer of the present invention. First, the dense layer slurry is poured into the mold 1 and pressed by the roll press 3 to form the dense layer 2. FIG.
It represents a step of forming a foam layer. The foam layer slurry is poured onto the dense layer 2 formed in the previous step, and the foam layer 4 is formed by heat curing treatment. FIG.
The step of pouring the same dense layer slurry as that poured in FIG. 1 onto the foam layer 4 and completely heating and curing the same is shown. Then, by removing the laminate from the mold 1, the inorganic laminate of the present invention can be manufactured.

[0046]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. Examples 1-6 and Comparative Examples 1~6 SiO ₂ -Al ₂ O ₃ system Preparation of powder (SiO ₂ -Al ₂ O ₃ system powder A) fly ash (KANDEN Chemical Co. Ltd., average particle size 20 [mu] m; JIS A 6201
According to the above) by means of a sphere separator (manufactured by Nisshin Engineering Co., Ltd., model: TC15) to obtain SiO ₂ —Al ₂ O ₃ based powder A containing 100% by weight of powder having a particle size of 10 μm or less. It was

(SiO_Two-Al_TwoO_ThreePowder B) Kaori
(Composition; SiO_Two45.7%, Al_TwoO_Three38.8
%, Average particle size 5 μm, BET specific surface area 5.8 m^Two/ G)
Melted at 3000 ° C and sprayed into the atmosphere at a speed of 80 m / s
Fog and average particle size 5μm, specific surface area 9.5m^Two/ G of Si
O_Two-Al _TwoO_ThreeA system powder B was obtained. (Alkali metal silicate aqueous solution) With the composition shown in Table 1,
JIS No. 1 sodium silicate aqueous solution (Nippon Chemical Industry Co., Ltd.
1K potassium silicate aqueous solution (Nippon Kagaku Kogyo Co., Ltd.)
And alkali metal silicate aqueous solution (1),
And the alkali metal silicate aqueous solution (2) was prepared.

[0048]

[Table 1]

(Hydrogen peroxide) Hydrogen peroxide solution has a concentration of 35%
(Mitsubishi Gas Chemical Co., Ltd.) diluted to a concentration of 3% was used. (Foaming aid) Zinc stearate SZ20 as a foaming aid
00 (made by Sakai Chemical Industry Co., Ltd.) was used.

The dense layer slurry was prepared by mixing the mixed powders in the amounts shown in Tables 2 and 3 for 2 minutes using an omnimixer (Chiyoda Giken Kogyo Co., Ltd.). The slurry for the foam layer was prepared by mixing the mixed powders having the blending amounts shown in Tables 2 and 3 with an omni mixer for 2 minutes and then adding hydrogen peroxide (3
5%), water, and a foaming auxiliary agent were added, and the mixture was further mixed with an omni mixer for 30 seconds to prepare a mixture. The dense layer slurry is poured into a concavo-convex mold having inner dimensions of 150 × 50 × 20 mm,
This was set in a press machine and pressed. The pressing pressure was 20 kg / cm ² . The foam layer slurry was poured onto the dense layer, and heat-cured while foaming using an oven set at 85 ° C. Furthermore,
A dense layer slurry having the same composition as the dense layer slurry used in the first layer was poured. Then, by using an oven set to 85 ° C., complete heating and curing to form an inorganic laminate,
I demolded. The surface hardness and appearance of the obtained inorganic laminate were evaluated by the following methods. The results are shown in Tables 2 and 3. The laminates obtained in Comparative Examples 1 to 3 were
The viscosity of the dense layer slurry was too low to be pressed.

[Evaluation of Laminated Body] Surface hardness: Vickers hardness meter (MVK-50, manufactured by Akashi Seisakusho Co., Ltd.) was measured with a load of 500 g. Appearance: Whether bubbles are visible on the surface. In addition, it was evaluated whether or not the mold could be molded in the same shape, the right angle and the depth. ⊚: No defective appearance. The same shape as the mold with sharp corners. ◯: Almost no appearance defect. X: Occurrence of poor appearance is observed.

[0052]

[Table 2]

[0053]

[Table 3]

[0054]

EFFECT OF THE INVENTION Since the method for producing an inorganic laminate of the present invention is as described above, it can be produced in a short process without requiring heat treatment when forming a dense layer, and the produced inorganic laminate is The body can be made highly decorative with an outer layer having a deep uneven pattern, has high strength and is lightweight, and is useful as a building member or the like.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a method of pouring the dense layer slurry of the present invention into a mold,
It is a figure showing one Embodiment of the process of forming a dense layer by pressing with a press molding machine.

FIG. 2 is a diagram showing an embodiment of a process of forming a foamed layer by pouring the foaming layer slurry of the present invention onto a dense layer and performing heat curing treatment while foaming.

FIG. 3 is a diagram showing an embodiment of a step of forming a laminate by pouring the dense layer slurry of the present invention onto the foam layer and performing a complete heat curing treatment.

[Explanation of symbols]

 1 type 2 dense layer 3 roll press 4 foam layer

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display area // (C04B 28/26 22:00 24:04) 103: 42 103: 48 111: 20

Claims (1)

[Claims] 1. A method for producing an inorganic laminate, comprising a dense layer and a foam layer laminated together, comprising a slurry comprising SiO ₂ —Al ₂ O ₃ -based powder, an alkali metal silicate, and water. A step of forming a dense layer by pouring into a mold and pressing with a press molding machine, SiO ₂ —Al ₂ O
Slurry consisting of ₃ type powder, alkali metal silicate, water, and at least one of a foaming agent and a foaming agent is poured onto the dense layer in the mold, and heat curing treatment is performed while foaming. To form a foam layer, and Si
A slurry composed of O ₂ —Al ₂ O ₃ -based powder, an alkali metal silicate, and water is poured onto the foam layer in the mold, and then the whole is completely heat-cured to form a laminate. Then, the method for producing an inorganic laminate, which comprises a step of demolding.