JPH11228252A - Production of inorganic foamed roof tile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing inorganic foamed tiles having excellent light weight and thermal insulation properties. SOLUTION: This inorganic foam tile production process comprises the first step in which a SiO2 -Al2 O3 inorganic powder, an alkali metal silicate, a foaming agent and water are mixed and the homogeneously mixed composition is cast into molds, the second step in which the mixed composition is foamed in the molds, then cured by heating to give the inorganic cured products and the third step in which the inorganic cured products are coated with an impregnating water absorption inhibitor on their surfaces of the cured products and cured to give the objective water-resistant and water-repellent inorganic cured products.

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 foamed tile having mechanical strength, light weight and excellent heat insulation.

[0002]

2. Description of the Related Art In recent years, lightweight tiles, mainly cement tiles, have begun to spread in houses in order to improve earthquake resistance. For this reason, various proposals have been made to improve the performance of lightweight roofing materials and reduce their costs.
JP-A-4-327634 discloses waste plastic,
A roofing material composed of an inorganic base material and a metal reinforcing material has been proposed, and the roofing material has been reduced in weight by melting and molding an inorganic base material such as a natural balloon together with waste plastic. However, the above-mentioned roofing material is inferior in fire resistance and fire resistance because waste plastic is used, and metal is used as a reinforcing material. Was significantly reduced.

Japanese Utility Model Publication No. Hei 5-4487 proposes a thin-walled tile, in which a plurality of substantially U-shaped small split portions are integrated in the vertical and horizontal directions to reduce the roofing loss, thereby reducing the weight. Is planned. However, even if the metal roof is thin, the metal has high heat conduction, and the heat insulation must be sacrificed instead of reducing the weight.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a method of manufacturing an inorganic foamed tile excellent in light weight and heat insulation. .

[0005]

Means for Solving the Problems The method for producing an inorganic foamed tile according to the first aspect of the present invention (hereinafter referred to as the first invention) comprises an SiO ₂ -Al ₂ O ₃ -based inorganic powder, an alkali metal silicate. A first step of injecting a uniform mixed composition of a foamable inorganic composition comprising a salt, a foaming agent, and water into a mold, foaming the uniform mixed composition in the mold, heating and curing. A second step of obtaining a cured inorganic substance, and a third step of applying a permeable water-absorbing agent to the surface of the cured inorganic substance and curing the cured inorganic substance to obtain a water-resistant, water-repellent cured inorganic substance. I do.

The invention described in claim 2 of the present application (hereinafter referred to as “second
In the method for producing an inorganic foam tile according to the first aspect of the present invention, the uniform mixture composition is foamed and filled in a mold in the first step according to the first invention, and then the mold is continuously formed while foaming is continued. A second step of obtaining an uncured body of the inorganic foamed tile having a skin by vibrating to break bubbles on the contact surface of the mold, heating the uncured body together with the mold to form an inorganic foamed tile having a skin. It comprises a third step of obtaining a cured body.

[0007] The invention described in claim 3 of the present application (hereinafter referred to as "third")
The method for producing an inorganic foam tile according to the first invention or
In the second invention, the foamable inorganic composition comprises SiO 2_Two−
Al _TwoO_Three100 parts by weight of inorganic powder, alkali metal silicon
0.2-450 parts by weight of acid salt, 0.01-10 parts by weight of foaming agent
And 35 to 1500 parts by weight of water
And

The invention described in claim 4 of the present application (hereinafter referred to as the fourth
The method for producing an inorganic foam tile according to the first to _third aspects is characterized in that the SiO ₂ —Al ₂ O ₃ -based inorganic powder is fly ash.

Since the first to fourth inventions relate to a method for producing an inorganic foamed tile, they are collectively referred to as a production method of the present invention.
It will be referred to as the manufacturing method of the invention.

Hereinafter, in the production method of the present invention, the foamable inorganic composition, which is a common raw material, will be described sequentially,
The steps of each invention will be described.

The SiO ₂ —Al ₂ O ₃ based inorganic powder is
The total component of SiO ₂ and Al ₂ O ₃ is an inorganic powder having a content of 50% by weight or more, and a composition having 10 to 90% by weight of SiO _{2 and} 90 to 10% by weight of Al ₂ O ₃ is preferable. It is preferably used. When the content of the above components is less than 50% by weight, the reactivity of the mixture of the alkali metal silicate and water (the aqueous solution of the alkali metal silicate) decreases, and the mechanical strength of the obtained inorganic foam tile decreases.

Specific examples of the above SiO ₂ —Al ₂ O ₃ type inorganic powder include: (1) fly ash containing 80% by weight or more of particles having a particle size of 10 μm or less;
(3) Fly ash, clay, or a mixture thereof containing 80% by weight or more of particles having a particle size of 10 μm or less fired at 0 to 1000 ° C. is melted and obtained by spraying into a gas. Inorganic powder,
(4) The inorganic powder obtained by applying mechanical energy of 0.1 to 30 kwh / kg to the clay, (5) The inorganic powder obtained in the above (4) is further subjected to 100 to 750.
Inorganic powder obtained by heating to a temperature of ° C.
(6) an inorganic powder obtained by applying a mechanical energy of 0.1 to 30 kwh / kg to metakaolin, (7)
Examples include ash of an electrostatic precipitator generated when corundum or mullite is produced, (8) pulverized calcined bauxite, (9) metakaolin, and the like, and at least one of these can be used.

The above fly ash is JIS A6
A fine particle size ash sampled by a dust collector from a pulverized coal combustion boiler specified in 201, SiO ₂ 40% or more, moisture 1% or less, specific gravity 1.95 or more, specific surface area 2700 cm ²
/ G or more and 75% or more passing through a 44 μm standard sieve.

The mechanical energy is not particularly limited, and includes, for example, energy due to compressive force, shear force, impact force and the like. The method for applying mechanical energy is not particularly limited, and the method can be carried out using a crushing device generally used for crushing. Such crushers include, for example, impact, friction,
Ball media mills such as ball mills, vibration mills, planetary mills, and media stirring mills that combine compression and shearing; roller mills; mortars; It is also possible to use a jet crusher whose main purpose is impact and grinding. Among them, a ball medium mill is preferable because mechanical energy can be effectively applied to the inorganic powder mechanically.

The alkali metal silicate has a general formula of M ₂ O.
n SiO ₂ (M = Li, K, Na or a mixture thereof), wherein the number n is preferably n = 0.05
To 8, more preferably n = 0.1 to 3, and most preferably n = 0.5 to 2.5. When n exceeds 8, the alkali metal silicate aqueous solution is liable to gel, and the viscosity rapidly increases, so that it becomes difficult to mix with the powder. When n is less than 0.05, the mechanical strength of the inorganic foamed tile decreases. The alkali metal silicate is preferably added and mixed in the form of an aqueous solution from the viewpoint of reaction control.

The concentration of the aqueous alkali metal silicate solution is not particularly limited, but is preferably from 10 to 60% by weight. If the concentration of the aqueous alkali metal silicate solution exceeds 60% by weight, a viscosity suitable for producing an inorganic foamed tile cannot be obtained. On the other hand, when the amount is less than 10% by weight, water is excessive, so that shrinkage is large at the time of curing, and a predetermined mechanical strength cannot be obtained.

The added amount of the alkali metal silicate is SiO ₂
To -al ₂ O ₃ based inorganic powder 100 parts by weight, 0.2
To 450 parts by weight, more preferably 10 to 3 parts by weight.
50 parts by weight, most preferably 20 to 250 parts by weight. If the amount of the alkali metal silicate is less than 0.2 parts by weight, the curing will be poor because the amount of alkali required for the reaction is too small. Conversely, if it exceeds 450 parts by weight,
Since the amount of the curing agent is large, the water resistance of the inorganic foam tile deteriorates.

The amount of water added to the SiO ₂ —Al ₂ O ₃ based inorganic powder and the alkali metal silicate is SiO ₂ —A
35 to 1500 per 100 parts by weight of l ₂ O ₃ powder
It is preferably from 45 to 1000 parts by weight, most preferably from 50 to 500 parts by weight. If the amount of water exceeds 1500 parts by weight, the viscosity at the time of producing the inorganic foam tile decreases, the foaming stability deteriorates, and the strength of the obtained inorganic foam tile decreases. On the other hand, if the amount is less than 35 parts by weight, the viscosity is too high, which is not suitable for foaming.

The foaming agent is selected from the group consisting of SiO ₂ —Al ₂ O ₃ -based inorganic powder, alkali metal silicate and water.
It is a raw material that is decomposed and gasified to form bubbles inside, and examples thereof include peroxide and metal powder.

As the peroxide, oxygen is generated in the presence of an alkali, for example, hydrogen peroxide, sodium peroxide,
Potassium peroxide, sodium borate and the like can be mentioned, but hydrogen peroxide is preferably used in view of cost, safety, availability, and workability. The concentration of these aqueous solutions is preferably from 0.5 to 35% by weight, more preferably from 1 to 25% by weight, and if it is less than 0.5% by weight, the viscosity is too low and the bubbles are broken to produce. No, 35
If the content exceeds% by weight, the foaming speed is too fast, and foaming becomes unstable.

The metal powder reacts with an alkali to generate hydrogen, for example, Mg, Ca, Cr, Mn,
Fe, Co, Ni, Cu, Zn, Al, Ga, Sn, S
i, powders such as ferrosilicon, and the like, but aluminum powder is preferably used in view of cost, safety, availability, and workability. The average particle size of the metal powder is
If it is less than 1 μm, the reaction is rapid and the generation of foaming gas is too early, and if it exceeds 200 μm, the reaction is too slow and foaming stability is poor.

The amount of the foaming agent such as the peroxide and the metal powder is preferably 0.01 to 10 parts by weight based on 100 parts by weight of the SiO ₂ —Al ₂ O ₃ inorganic powder. 0.0
When the amount is less than 1 part by weight, the expansion ratio of the inorganic foam tile becomes too small, and light weight and heat insulation cannot be obtained. When the amount exceeds 10 parts by weight, the amount of foaming gas becomes excessive and bubbles are ruptured.

In the production method of the present invention, if necessary, an inorganic filler, a reinforcing fiber, a foaming aid, an inorganic foam, and the like may be appropriately added. The additives will be described below in order.

The inorganic filler contributes to reduction of shrinkage during curing, improvement of fluidity of the homogeneous mixture of the foamable inorganic composition, densification of cells, stabilization of bubbles, and the like. , Fly ash, slag, silica fume, mica, talc, wollastonite, calcium carbonate, aerosil, silica gel, zeolite, activated carbon, and porous body of alumina gel.

The average particle size of the inorganic filler is from 0.01 μm to
A range of 1 mm is preferable, and if it exceeds 1 mm, a stable inorganic foam tile cannot be obtained, and if it is 0.01 μm or less, the amount of adsorbed water increases, and the viscosity of the uniform mixture of the foamable inorganic composition increases, The workability is poor, and the foaming property is reduced.

The amount of the inorganic filler added is SiO ₂ --Al ₂
The amount is preferably from 20 to 600 parts by weight, more preferably from 40 to 400 parts by weight, per 100 parts by weight of the O ₃ -based inorganic powder. If it is less than 20 parts by weight, there is no point in adding a filler, and if it exceeds 600 parts by weight, the strength of the inorganic foamed tile decreases.

The reinforcing fibers improve the strength of the inorganic foam tile and help prevent cracks. For example, vinylon, polypropylene, aramid, acrylic, rayon, carbon,
Examples include glass, potassium titanate, alumina, steel, slag wool, and the like.

The length of the reinforcing fibers is preferably in the range of 1 to 15 mm. If the length is too long, the dispersibility of the reinforcing fibers of the inorganic foam tile becomes poor, and if it is too short, the inorganic foam tile has a desired strength. I can't.

The diameter of the reinforcing fibers is preferably from 1 to 500 μm.
It re-aggregates and fiber balls are formed, and the strength of the inorganic foam tile does not improve. When the thickness is large, the effect of reinforcement is small.

The amount of the reinforcing fiber added is SiO ₂ —Al ₂ O
It is 10 parts by weight or less based on 100 parts by weight of the _third inorganic powder. If the amount exceeds 10% by weight, the dispersibility in the foamable inorganic composition will be reduced.

The foaming aid contributes to stabilization of foaming, uniformity and fineness, and examples thereof include a porous powder and a surfactant. As the former, for example, silica gel, zeolite, activated carbon,
Alumina gel and the like can be mentioned, and its addition amount is preferably 5 parts by weight or less. If it is too large, the bubbles are broken, which adversely affects the production of the inorganic foam tile. The latter include fatty acid metal salts such as metal stearate, metal oleate and metal palmitate, such as zinc stearate, calcium stearate, aluminum stearate, sodium oleate, potassium oleate, and palmitate. Sodium, potassium palmitate, sodium laurylbenzenesulfonate, sodium lauryl sulfate and the like.

The amount of the foaming assistant is SiO ₂ —Al ₂ O
_{The amount} is preferably 0.05 to 5 parts by weight, more preferably 0.3 to 3.0 parts by weight, based on 100 parts by weight of the ₃ type inorganic powder. If the addition amount exceeds 5 parts by weight, the viscosity of the homogeneous mixture of the foamable inorganic composition increases, which adversely affects the production. Conversely, if the addition amount is less than 0.05 parts by weight, the bubbles are broken. Production is not stable.

The inorganic foam helps to reduce the weight of the inorganic foam tile. Examples of the inorganic foam include glass balloons, shirasu balloons, fly ash balloons, silica balloons, pearlite, hill stones, and particulate foamed silica. Can be used. These specific gravities are 0.01 to 1
And more preferably 0.03 to 0.7.
When the specific gravity is less than 0.01, the mechanical strength of the inorganic foamed tile is reduced, and when it exceeds 1, it does not contribute to weight reduction. The addition amount of the inorganic foam _is against SiO 2 -Al ₂ O ₃ -based inorganic powder 100 parts by weight, preferably 10 to 100 parts by weight, and more preferably from 30 to 80 parts by weight. If the addition amount is less than 10 parts by weight, the effect of weight reduction cannot be obtained, and if it exceeds 100 parts by weight, the mechanical strength of the inorganic foam tile lowers.

Next, each step in the manufacturing method of the first invention will be described below. The first step is, as described above, a step of injecting the homogeneous mixed composition of the foamable inorganic composition into the mold, and comprises the step of forming the SiO ₂ —Al ₂ O ₃ -based inorganic powder, the alkali metal silicate. , A foaming agent, a mixture of water and at least one of a foaming aid, a foaming agent, an organic or inorganic foam, an inorganic filler, a reinforcing fiber, etc., depending on the purpose.
The seeds are added to form a foamable inorganic composition, and the mixture is uniformly mixed by a mixer to obtain a self-foaming uniform mixture composition. Thereafter, the mixture is added to a mold of an inorganic foam tile having a predetermined shape. A homogenous composition is injected.

The mixing of the above-mentioned various composition raw materials is not particularly limited as long as they are uniformly mixed, and usually, a mixer such as an omni mixer or an Erich mixer is suitably used. Among these compositions, since the gas generating reaction is started by mixing the blowing agent with the alkali metal silicate, the foaming agent is formed at the very end to further increase the uniformity of the foamable inorganic composition. Preferably, the agents are mixed. Thus, the foamable inorganic composition is made into a self-foaming homogeneous mixture composition, and a predetermined amount is poured into a mold of the inorganic foam tile having a predetermined shape, and immediately, the foaming and curing reaction is gradually performed inside the mold. Begins to progress, and eventually the mold is filled in the early stage of the second step.

The second step of the first invention is a step in which the homogeneous mixed composition is foamed in a molding die, and then heated and cured to obtain a cured inorganic material.
The curing is promoted, and the mechanical strength of the obtained inorganic cured product is also improved. The heating temperature is preferably from 40 to 120 ° C, more preferably from 50 to 100 ° C. Heating temperature is 4
If the temperature is lower than 0 ° C., the heating time is too long, resulting in poor productivity. It is necessary to pressurize the mold.

In the third step of the first invention, a permeable water-absorbing inhibitor is applied to the surface of the inorganic cured product and cured to obtain a water-resistant material.
This is a step of obtaining a water-repellent inorganic cured body, in which the inorganic cured body is taken out of the mold of the inorganic foam tile, a permeable water-absorbing agent is applied to the surface of the inorganic cured body, and this is dried or cured. This is a step of obtaining a water-resistant and water-repellent inorganic cured body.

The permeable water-absorbing agent is not particularly limited as long as it is a water-absorbing agent permeable to the inorganic cured product used in the present invention, and is widely used in the world. A water repellent and a waterproofing agent are used, and for example, an alkoxysilane represented by the following general formula (1) is suitably used. _An Si (OB) _4-n ... (1) A is an alkyl group having 1 to 25 carbon atoms. In order to further improve the hydrophobicity, an alkyl fluoride group or the like is preferable. 1 to 5 alkyl groups, and n is a natural number of 1 to 3.

As the compound represented by the general formula (1),
For example, when n = 1, methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-propoxysilane, methyltri-iso-propoxysilane, methyltri-n-butoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane Methacryloxypropyltrimethoxysilane, mercaptopropyltrimethoxysilane, and trimethylaminotrimethoxysilane. When n = 2, for example, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldi-n
-Propoxysilane, dimethyldi-iso-propoxysilane, dimethyl-n-butoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, γ-glycidoxypropylmethyldisiethoxysilane, and the like.When n = 3, for example, , Trimethylmethoxysilane, trimethylethoxysilane, trimethyl-n-propoxysilane, trimethyl-iso-propoxysilane, tristearylmethoxysilane, trioleylmethoxysilane and the like.

In the presence of water, alkylalkoxysilanes spontaneously hydrolyze to form alkylsilanols and alcohols, and the alkylsilanols react with the hydroxyl groups of silicon and aluminum on the surface of the inorganic cured product, and at the same time, react with themselves. Condensation forms a siloxane bond to form a polymer. In the general formula (1), when n is 1, the alkylsilanol crosslinks into a two-dimensional structure. When n is 2, it forms a linear polymer, and when n is 3, it forms a dimer. Therefore, n
However, the alkylalkoxysilanes 1 and 2 hydrophobize the hydrophilic groups on the surface of the inorganic cured product, and further grow a silicon compound thereon to increase water resistance and water repellency.

The alkylalkoxysilane is preferably diluted with an organic solvent for uniform application, and is not particularly limited as long as it can be dissolved uniformly. Examples thereof include alcohols such as ethyl alcohol, n-propanol, i-propanol and t-butanol. , Ethylene glycol monomethyl ether, ethylene glycol monoester ether, ethers such as ethylene glycol diethyl ether, acetone, ketones such as methyl ethyl ketone,
Alkanes such as fatty acid naphtha and mineral spirits,
Examples thereof include hydrocarbons such as toluene, xylene, sorbennaphtha and aromatic naphtha, and halogenated hydrocarbons such as trichloroethylene and perchloroethylene, and at least one of these can be used.

The concentration of the organic solution of the above-mentioned alkylalkoxysilane in the organic solvent is preferably 5 to 20% by weight, and when the concentration is within this range, it can be suitably applied to the inorganic cured product. The coating amount of the organic solution is calculated in terms of alkylalkoxysilane,
0.05 to ² kg / m ² is preferred, and 0.05 kg / m ²
When it is less than m ² , water resistance and water repellency are insufficient, and 2 kg /
Even if it exceeds m ² , the water resistance and the water repellency are not improved as compared with the coating amount. In the above solution, for the purpose of promoting the condensation reaction,
A catalyst such as dibutyltin laurate is added,
Pigments, fillers, and the like may be added as appropriate for the purpose of coloring and increasing the amount thereof, depending on the purpose.

The application method is not particularly limited, and known methods such as air spray, roll, brush, and dipping can be applied. After application, the alkylalkoxysilane is cured and fixed. It is preferable to leave the above, and further heat at 50 to 110 ° C.

In the manufacturing method of the first invention described above, one of the raw materials of the inorganic foamed tile is SiO ₂ —Al ₂
When fly ash having a particle diameter of 10 μm or less is used as the O ₃ -based inorganic powder, the obtained inorganic foam tile can be finished in a natural gray-black color without painting. Therefore, when producing a gray-black inorganic foamed tile, it is economically advantageous because a transparent permeable water-absorbing agent used on the surface is sufficient.

Next, each step in the manufacturing method of the second invention will be described below. The first step of the second invention is
Similar to the first step of the first invention, the uniform mixture composition of the foamable inorganic mixture composition as described above is poured into a mold of an inorganic foam tile having a predetermined shape.

The second step is to foam and fill the homogeneous mixed composition in a mold, and then continuously vibrate the mold while continuing foaming to break bubbles on the contact surface of the mold. A step of obtaining an uncured body of an inorganic foamed tile having a skin, wherein a uniform mixed composition foamed inside the mold of the inorganic foamed tile, and filled, is vibrated by the vibration of the mold, at a contact surface thereof. The bubbles are destroyed, and a skin having a low foaming ratio on the surface is formed. However, since the foaming of the homogeneous mixture composition is still continuing, the mold is filled again, the bubbles at the contact surface of the mold are broken, and the thickness of the outer skin of the surface maintains the growth, and this cycle is repeated. Is performed continuously. The longer the duration of the above cycle, the greater the thickness of the outer skin,
The expansion ratio (apparent density) of the outer skin can be controlled from unfoamed to low foamed by the composition of the homogeneous mixture composition.

The vibration applied to the mold is not particularly limited, and can be achieved by equipping a usual vibration motor, vibrator, vibrator and the like. The frequency applied to the mold is preferably 100 to 10000 Hz. If the frequency is less than 100 Hz, the bubbles in the outer skin are not sufficiently destroyed. If the frequency exceeds 10,000 Hz, the energy is too large and the bubbles are destroyed too severely. The amplitude of the vibration is 1
When the amplitude is less than 1 μm, the bubbles are not sufficiently broken, and the amplitude is 500 μm.
When the temperature exceeds the above, the destruction of air bubbles may reach the center of the mold.

In the process of foaming and crust formation of the above-mentioned homogeneous mixture composition, the foaming reaction and the curing reaction proceed simultaneously in parallel, and the viscosity of the composition gradually increases. Therefore, in the final stage of the second step, the “uncured body” having the outer skin in the mold does not mean a completely uncured state, but means a cured body in an incompletely cured state. .

The third step is a step of heating the uncured body together with the mold to obtain a cured body of the inorganic foamed tile having a skin. Is completed, and after completion of curing, the inorganic foam tile having the skin is removed from the mold. The heating temperature in the third step is preferably from 40 to 120C, more preferably from 50 to 100C. When the heating temperature is lower than 40 ° C., the curing reaction is too slow and the productivity is poor. It is necessary to pressurize the mold.

The inorganic foamed tile obtained by the present invention has 1
It is preferable that the average cell diameter be 0 μm to 5 mm, the cell wall thickness between cells be 0.05 to 5 mm, and the bulk density be 0.2 to 1.0 g / cm ² .

When the average bubble diameter is less than 10 μm, the surface area of the film constituting the bubbles becomes large, and as a result, the thickness of the partition walls of the bubbles becomes thin, and the mechanical strength is reduced.
When it exceeds, the gas in the air bubbles is convected, and the heat insulating property is reduced. When the thickness of the cell wall between the cells is less than 0.05 mm, the mechanical strength decreases, and when it exceeds 5 mm, the heat insulating property decreases. When the bulk density is less than 0.2 g / cm ³ ,
If the mechanical strength is reduced and exceeds 1.0 g / cm ³ , the heat insulating property is reduced. Incidentally, the average cell diameter, the average cell wall thickness,
The bulk density is measured based on an evaluation method described later.

[0052]

According to the production method of the first invention, a homogeneous mixed composition of a foamable inorganic composition is poured into a mold, foamed, heated, and cured to form a cured inorganic substance, and the surface thereof is prevented from absorbing water. Applying and curing the agent to obtain a water-resistant, water-repellent inorganic cured product, instead of making the entire composition of the inorganic foam tile water-resistant and water-repellent, the outer surface of the inorganic cured product and its surrounding skin Water-absorbing agent at a high concentration
The water repellency is effectively improved, and the skin formed on the surface contributes to the improvement of the mechanical strength of the inorganic foam tile.

In the production method of the second invention, the homogeneous mixture composition of the expandable inorganic composition is poured into a mold, foamed, and then the mold is vibrated to form an outer skin on the surface. By curing this, it becomes an inorganic foam tile with a dense outer skin on the surface, effectively improving water resistance and water repellency,
At the same time, the skin formed on the surface contributes to improving the mechanical strength of the inorganic foam tile.

[0054]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Examples 1 to 4 (1) First step Fly ash (manufactured by Kanden Kakoh Co., Ltd., average particle diameter according to JIS A 6201: 20 μm) was prepared as an SiO ₂ —Al ₂ O ₃ based inorganic powder. This was introduced into a classifier (TC-15, manufactured by Nisshin Engineering Co., Ltd.) to obtain fly ash having an average particle size of only 10 μm or less.

Next, as shown in the formulation of the expandable inorganic composition in Table 1, 100 parts by weight of the fly ash having an average particle diameter of 10 μm or less was added to a 40% aqueous solution of sodium silicate (Si
O ₂ / Na ₂ O, molar ratio: 1.5) 125 parts by weight, viscosity-adjusted water, talc (manufactured by Sanyo Clay Industry Co., Ltd., talc 83, average particle diameter 5 μm), mica (szolite mica, average particle diameter 40 μm) , Vinylon fiber (manufactured by Kuraray Co., Ltd., RM18
2-3, a fiber length of 3 mm) was stirred and mixed with a hand mixer to prepare a uniform mixed solution. Then, aluminum powder or hydrogen peroxide water (manufactured by Mitsubishi Gas Chemical Company, 35 wt%, 10 wt%
) Was added in a predetermined amount, and the mixture was stirred and mixed for about 10 seconds to prepare a uniform mixed composition of the foamable inorganic composition, which was poured into a urethane rubber mold having a Japanese roof tile shape.

(2) Second Step When the mold into which the homogeneous mixed composition obtained in the above (1) was poured was placed in a hot air dryer at 85 ° C., foaming gradually occurred, and the mold was filled. Further, heating was continued at 85 ° C. for 12 hours to complete the curing as much as possible. After a while
The cured inorganic material together with the molding die was taken out of the dryer, and the mold was removed to obtain various cured inorganic materials molded into a Japanese roof tile shape. With respect to the inorganic cured product obtained above, the average cell diameter, the average wall thickness, and the bulk density were measured based on the evaluation method described later, and the results are summarized in Table 1.

[0058]

[Table 1]

(3) Third Step The cured inorganic material obtained in the second step is further heated at 50 ° C. for 8 hours.
After drying for an hour, 300 g / m ² of a permeable water-absorbing inhibitor (Aqua Seal 1100W, manufactured by Sumitomo Seika Co., Ltd.) was applied to the surface, and left at room temperature for 12 hours to obtain various inorganic foam tiles.

Examples 5 to 8 (1) First step As shown in Table 2, in the same manner as in (1) First step of Examples 1 to 4, foamable inorganic compositions were prepared and various foaming compositions were prepared. A homogeneous mixed composition of the conductive inorganic composition was prepared and poured into a urethane rubber mold having a roof tile shape.

(2) Second Step When the mold into which the homogeneous mixed composition has been poured is left for 5 to 10 minutes, foaming gradually occurs, and the mold fills up and overflows from an overflow hole provided in advance in the mold. Of the homogeneous mixed composition overflowed. Thereafter, a vibration frequency of 2000 Hz and an amplitude of 100 were applied from both sides of the mold using a vibrator.
A vibration of μm was applied for 15 seconds to obtain an uncured inorganic foam tile having a skin in the mold.

(3) Third Step The uncured product obtained in the second step is mixed with a molding die in
The uncured product was heated and cured in a dryer at 5 ° C. for 12 hours. Thereafter, the inorganic foam tile was removed from the mold to obtain inorganic foam tiles of Examples 5 to 8. With respect to the obtained inorganic foam tile, the average cell diameter, the average cell wall thickness, the bulk density, and the falling ball test were measured based on the evaluation method described later, and Table 2 summarizes the results.

Comparative Example 1 As shown in Table 2, an inorganic foamed tile was produced in the same manner as in Example 5 except that no vibration was applied to the mold in the second step, and an evaluation method described later was used. Average bubble diameter, based on
The average cell wall thickness, bulk density, and falling ball test were measured, and Table 2 summarizes the results.

[0064]

[Table 2]

Examples 9 and 10, Comparative Example 2 and Comparative Example 3 A plywood with a thickness of 12 mm and a 4.5-degree gradient facing south was used as a base plate, and asphalt roofing (22 kg / m
² ), and as shown in Table 3, four types of inorganic foam tiles obtained in Example 1 and Example 5, commercially available color vest (slate roof, black) and Japanese tile (porcelain, gray black) The roof was installed. Then, the solar energy was 760 kcal / m ² h on the roof surface and the outside air temperature was 30 ° C.
The maximum attainable temperature of the back surface of the field board was measured, and the results are shown in Table 3.

[0066]

[Table 3]

Evaluation method (a) Average cell diameter 50 × 50 × 15 m on one side from cured inorganic material other than skin
A rectangular parallelepiped of m was cut out, and the plane and both sides were photographed with a microscope. On the above photo, draw two straight lines that are perpendicular to each other and parallel to the ridge line of each surface, and individually continue the distance from any pore membrane to the point where the next pore membrane is cut along one straight line The same operation is performed for the second straight line. The total distance is counted
) Was defined as the average cell diameter on this surface. The distance was measured and converted on a scale stamped on a slide of a reflection microscope. The average cell diameter used in the present invention was used because no difference was observed in the average cell diameters in the vertical, horizontal and height directions.

(B) Average Cell Wall Thickness From the photograph in (a) above, 100 cell walls were measured and averaged.

(C) Bulk density 50 × 50 × 15 m on one side from cured inorganic material other than skin
Cut a rectangular parallelepiped m, and the weight thereof was measured W _0, it was calculated by dividing its volume V _0. That is, the bulk specific gravity ρ = W ₀ / V
₀

(D) Falling Ball Test A falling ball test was performed on the inorganic foamed tile according to JIS A 5423, and the presence or absence of abnormality was visually confirmed.

[0071]

As described above, according to the present invention, an inorganic foam tile having excellent light weight, excellent heat insulation and excellent mechanical strength can be manufactured.

Claims (4)

[Claims] 1. A first step of injecting a uniform mixture of a foamable inorganic composition comprising an SiO ₂ —Al ₂ O ₃ based inorganic powder, an alkali metal silicate, a foaming agent, and water into a mold. After foaming the homogeneous mixed composition in a mold, heating and curing, a second step of obtaining an inorganic cured product, applying a permeable water-absorbing agent to the surface of the inorganic cured product, curing,
A method for producing an inorganic foam tile, comprising a third step of obtaining a water-resistant and water-repellent inorganic cured product. 2. The first step according to claim 1, wherein after the uniform mixed composition is foamed and filled in the mold, the mold is continuously vibrated while foaming is continued to form a contact surface of the mold. From the second step of obtaining an uncured inorganic foam tile having a skin by breaking bubbles, and the third step of heating the uncured body together with a mold to obtain a cured inorganic foam tile having a skin A method for producing an inorganic foamed roof tile. 3. The method according to claim 1, wherein the expandable inorganic composition comprises SiO ₂ —
Al ₂ O ₃ based inorganic powder 100 parts by weight, 0.2 to 450 parts by weight of alkali metal silicate, blowing agent 0.01 to 10 parts by weight, and, according to, comprising the water 35-1500 parts by weight The method for producing an inorganic foam tile according to claim 1 or 2. 4. An SiO ₂ —Al ₂ O ₃ based inorganic powder,
4. The method for producing an inorganic foam tile according to claim 1, wherein the foam is fly ash.