JPH10167852A - Production of lightweight hardened body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the lightweight hardened body highly resistant to freezing damage, without the sp.gr. being locally deviated, high in mechanical strength and capable of being finished homogeneously and densely by mixing a hydrophilic and substantially sublimable substance in a hydraulic material as a weight-reducing material, slurrying the mixture, compacting the slurry and hardening the compact. SOLUTION: A hydrophilic and substantially sublimable substance as a weight-reducing material (the surface is coated with a hydrophilic inorg. material of resin when poor in hydrophilicity) having 10-200μm grain diameter by 40-150 pts.wt. and an additive such as a reinforcement, aggregate and filler, as required, are mixed in 100 pts.wt. of a hydraulic material as the main raw material, and 50-200 pts.wt. of water is added to slurry the mixture. The slurry is compacted into a desired shape, the compact is pressed at 50-200kg/cm<2> pressure, heated, cured and hardened. The sublimable substance is sublimated simultaneously with, before or after the curing to obtain a lightweight hardened body.

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 a lightweight cured body, and more particularly to a method for producing a lightweight cured body often used as an outer wall or a partition wall of a building.

[0002]

2. Description of the Related Art Conventionally, a fiber-reinforced cement board obtained by mixing a reinforcing material or the like with a cement or a hydraulic material obtained by mixing a predetermined admixture with the cement, and molding and hardening the cement has been used.
It has been widely used as a building material for building outer walls and partition walls. Such building materials include, for example, an extruded cement board and a slate board, and a hardened material for reducing the weight of the material. Examples of the lightweight building materials include lightweight cellular concrete (hereinafter referred to as "ALC") having a porous inside and lightweight concrete in which a porous material powder is mixed with a material.

[0003] Extruded cement boards and slate boards, which are not lightened, are heavy and require time and labor for transportation and construction. Therefore, they are not preferred for building materials such as outer walls and partition walls of buildings. On the other hand, ALC is lightweight and easy to handle, and thus there is a tendency to use ALC frequently in such applications. ALC is generally manufactured by the following method. That is, a small amount of aluminum powder is mixed with a slurry obtained by mixing lime, Portland cement, calcareous components such as granulated blast furnace slag, finely ground silica, fibers, etc., and hydrogen gas is generated to solidify the foamed product. , After cutting it, put it in an autoclave
This is a method of curing by heating at 80 ° C. under a saturated vapor pressure for about 10 hours. Lightweight concrete is obtained by using a porous powder such as pearlite as an aggregate, mixing it with cement to form a slurry, molding and hardening the slurry.

[0004] In order to obtain a molded article having a desired shape from the slurry, a pouring method is carried out by pouring the slurry into a mold having a predetermined shape, and the slurry is extruded from an extruder through a die having a predetermined shape. An extrusion method for forming a molded body having a cross-sectional shape described above, and a papermaking method for forming a thin plate-like body by pouring a slurry onto a moving table. In order to obtain a complex shaped body by the casting method,
Many different types of formwork must be prepared. In the case of the extrusion method, there is an advantage that various shapes can be obtained only by changing the shape of the die.

[0005]

SUMMARY OF THE INVENTION AL which is a lightweight cured product
Conventionally, C has the following problems in its structure or its manufacturing method. ALCs produced by conventional methods generally have a myriad of small continuous tunnel-like cavities inside. When it is used for outer walls, water drops seep into it, and the water trapped inside freezes and melts repeatedly in winter. Therefore, there is a defect that a phenomenon called frost damage, that is, a phenomenon that a part is cracked or a layer part is peeled off and the mechanical strength is lost in a short time. In the case of the casting method in a mold, a complex molded body can be obtained by preparing a large number of molds, and a cured body having a complicated shape can be obtained by curing the molded body. Has the drawback that it has low strength, is brittle and easily breaks.

In the case of the extrusion method, which is not suitable for ALC, it can be applied to a method for producing lightweight concrete in which a porous material is mixed as a weight-reducing material. Will apply high pressure to the slurry. Then, the lightening material dispersed in the slurry receives a high pressure from the surroundings, or the surroundings become dense, and the porous state may not be maintained sufficiently at the curing stage. ALC, in which the lightening material did not sufficiently form bubbles during the curing stage, had a disadvantage that the weight was not sufficiently reduced as expected. In addition, when the lightening material has elasticity, such as when hard polyurethane is used as the lightening material, the extruder presses the slurry once, and when the pressurization is released in the curing stage, the slurry once contracts. The lightweight material is restored or springs back. At that time, the lightening material may move delicately in the slurry while discretely assembling. As a result, variously large and small bubbles are generated nonuniformly at concentrated locations and discrete locations. When a lightweight cured product obtained by manufacturing is surface-finished for various materials, there is a disadvantage that the surface condition is very rough.

[0007] Not only is such a material inferior in aesthetics, but even if an attempt is made to form a composite plate by laminating a plurality of plate materials in layers, the adhesion becomes poor, especially at locations where large bubbles are concentrated, and it is not sufficient. There is also a disadvantage that a composite plate having mechanical strength cannot be obtained. In the case of the papermaking method, the slurry is thinly and horizontally stretched on a flat surface. In general, since the weight-reducing material has a property that the specific gravity is light and easily floats, there is a drawback that bubbles gradually concentrate on one surface side during the curing stage, and the specific gravity becomes uneven in the thickness direction. Porous particles used in the production of lightweight concrete using the porous particles as a lightweight material, for example, pearlite, generally have a low specific gravity and are easily charged. Therefore, during manufacturing, the lightening material is poorly dispersed at the slurry stage and easily concentrates at one place, and the lightweight concrete manufactured using the lightening material has an uneven porous dispersion state, and Had the disadvantage that the specific gravity was uneven. The purpose of the present invention is
It is an object of the present invention to provide a method for producing a light-weight cured body that is resistant to frost damage, has no local deviation in specific gravity, has a large mechanical strength, is qualitatively uniform, and can finish the surface precisely. Is to do.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to mix a lightening material with a hydraulic material as a main raw material, add water to make a slurry, and then give a desired shape to obtain a molded article. A method for producing a lightweight cured product by curing the molded product, wherein a material having hydrophilicity and substantially sublimability is used as a weight-reducing material, and the molded product obtained by molding is pressed; Before or at the time of curing, the method can be achieved by a method for producing a lightweight cured body, which comprises vaporizing a substance having substantially sublimability to make it porous.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Examples of hydraulic materials to be blended with a weight-reducing material include various cements such as Portland cement, blast furnace cement, fly ash cement and the like. In addition, inorganic materials that react with water and harden, such as calcium silicates, gypsum, and slag gypsum, can be used. These may be used alone or in combination of two or more. In the production of a lightweight cured product, the particle size (the numerical value is an average particle size; the same applies hereinafter) of such a hydraulic material is generally preferably 1 to 50 μm.

As the lightening material to be mixed with such a hydraulic material, a substance having a substantially sublimable property is used. As used herein, the term "substantially sublimable substance" refers to a solid having no fluidity under normal temperature and normal pressure, and is easily vaporized. Refers to a substance. Specifically, adamantane represented by the following formula (1) can be mentioned, and in addition, solid paraffin,
Camphene, p-dichlorobenzene, cetyl alcohol,
Myristic acid, triphenyl phosphate, p-chloronitrobenzene and the like can also be mentioned. Camphene may be d-form or l-form (L-form). These may be used alone or in combination of two or more. Among them, adamantane is most preferable in terms of handling. P-dichlorobenzene and the like are also preferred. These substances are preferably harmless to the human body when vaporized.

[0011]

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When a sublimable substance is mixed with a hydraulic material, the sublimable substance has a particle size of 10 to 200 μm.
m is good. When the particle size exceeds 200 μm, the size of the pores in the lightweight cured product obtained by production becomes too large, and when used for an outer wall or the like, water droplets may invade and frost damage may not be sufficiently prevented, which is preferable. Absent. If the thickness is less than 10 μm, the sublimation speed inside the molded body is undesirably low. It is desirable that a substance having a sublimation property has hydrophilicity as a physical property so that the substance can be well dispersed in a hydraulic slurry. If the selected sublimable substance has poor hydrophilicity, hydrophilicity is imparted. Examples of the method for imparting hydrophilicity include a method of bonding a hydrophilic inorganic material to the surface of a sublimable substance, and a method of bonding a hydrophilic resin. Among them, what can be done easily and economically is
This is a method of bonding hydrophilic inorganic raw materials.

[0013] Examples of the hydrophilic inorganic raw material to be adhered when imparting hydrophilicity include silica powder and cement powder. As a hydrophilic resin,
For example, an ethylene vinyl acetate resin can be mentioned.
The adhesive for bonding such a hydrophilic inorganic material or resin may be any as long as it has a property that can hold the once bonded hydrophilic substance sufficiently in an aqueous slurry.
For example, an acrylic adhesive can be used. In imparting hydrophilicity, it is preferable to knead together a sublimable substance, an adhesive, and a hydrophilic inorganic material or resin together. When kneading, the sublimable substance has a particle size of 10
The particle size of the hydrophilic inorganic raw material or resin is preferably 1 to 20 μm. The amounts of the three components are as follows: the amount of the sublimable substance is 10 parts by weight, and the adhesive is 0.1 to 0.2.
It is preferable to use 1 part by weight, 1 to 5 parts by weight of a hydrophilic inorganic material or resin. Even if the sublimable substance itself is poor in hydrophilicity, by imparting hydrophilicity in this way, it is possible to maintain a sufficiently dispersed state in the slurry, and it is unlikely that the substance will precipitate or float. Become. Therefore, a substance having sublimability is less likely to be locally concentrated, and a homogeneous lightweight cured product can be manufactured.

Such a kneaded material generally agglomerates or coagulates as a granular material. The powder obtained by kneading may be pulverized again to a particle size of 10 to 50 μm, and then mixed with the hydraulic material as a sublimable substance. The substance having sublimability to be mixed with the hydraulic material preferably has a specific gravity of 0.8 to 1.2. In the case of a sublimable substance that needs to be imparted with hydrophilicity, the specific gravity after imparting hydrophilicity is preferably in this range. When the specific gravity is 0.95 to 1.05, the specific gravity is close to the specific gravity of water, and there is little precipitation or floating in the slurry. It is preferable because the local concentration of the lightening material can be prevented, and a homogeneous light cured material can be manufactured.

In the production of a light-weight cured product, in addition to a hydraulic material and a light-weight material, a reinforcing material, an aggregate, a filler, A
Additives such as an E agent and a water reducing agent dispersant can be contained as needed. As the reinforcing material, usually, inorganic fibers,
Various fibers such as organic fibers are blended. Examples of the inorganic fibers to be blended as the reinforcing material include metal fibers such as steel fibers and amorphous metal fibers, and non-metal fibers such as glass fibers, carbon fibers, and ore wool. As organic fibers, polypropylene fibers,
Examples thereof include polyamide fibers, polyvinyl alcohol fibers, and polyacryl fibers. In recent years, cotton,
Plant fibers such as hemp and pulp can also be used effectively. In some cases, an inorganic powder or the like may be blended as an aggregate or a filler. Such inorganic powders include silica sand, wollastonite, silica fume, fly ash,
Slag and the like can be mentioned.

When the hydraulic material is 100 parts by weight, the weight of the lightening material is 40 to 150 parts by weight, preferably 60 to 130 parts by weight. Preferably, it is 80 to 120 parts by weight. If the ratio of the weight-reducing material exceeds 150 parts by weight, it is not preferable because sufficient mechanical strength cannot be obtained in the light-weight cured product produced. If the amount is less than 40 parts by weight, a sufficient weight reduction cannot be achieved, which is not preferable. In the present invention, since the portion of the lightening material becomes a void in the product, the volume ratio of the lightening material to the entire material determines the degree of porosity of the product,
Since the lightness is also determined, it is preferable to determine the mixing ratio of the lightening material from the quality of the target product. When a reinforcing fiber is added, the amount of the hydraulic material is preferably 10 parts by weight or less based on 100 parts by weight.

Water is added to a mixture of the hydraulic material and the lightening material to form a slurry. The amount of water to be added is preferably 50 to 200 parts by weight based on 100 parts by weight of the hydraulic material. If the amount of water exceeds 200 parts by weight, the hydraulic material and the lightening material separate, which is not preferable. If the amount is less than 50 parts by weight, the curing reaction with the hydraulic material is not sufficiently performed, and it is not preferable because sufficient strength cannot be obtained. The slurry is formed by putting the hydraulic material, the weight-reducing material, the water, and the like into the mixer in the above-described ratio, further adding the required amount of aggregate, filler, and the like, and stirring the mixture.

Next, the slurry thus obtained is molded so as to give a desired shape, and the molded body is further pressed. Conventional molding methods such as an extrusion method, a casting method, and a papermaking method can be directly applied to the molding. FIG. 1 is a diagram showing an outline of the pouring method. As shown in FIG. 1, a substantially horizontal stainless steel table 1
A mold 2 for preventing outflow is provided around, and a slurry 4 is poured from a discharge port 3 of the mixer to fill the mold at a uniform height. The slurry solidifies after a predetermined time to obtain a molded body.

The obtained molded product is left as a single layer (single).
Alternatively, if necessary, several sheets are laminated and pressed. By performing the pressing, the filling property of the inorganic material in the molded body is improved, the density is increased, and the strength is increased. In the present invention, since a sublimable substance is blended as the lightening material, the lightening material is not broken or compressed by pressing. Since the strength is increased, there is no danger of being destroyed from the inside by the pressure due to the sublimable substance vaporized inside when heated to vaporize the sublimable substance. Further, a composite panel can be obtained by laminating a fiber cement raw plate having no holes on both sides of a lightweight molded body as a core material. On the other hand, when foamed resin particles are used as a lightening material as in the past, the particles are compressed when pressed, and when the pressure is released, the foamed resin particles are restored, and the surface condition becomes poor. On the other hand, in the case of a laminated plate, the adhesion between the layers is poor.

The pressing is performed, for example, as follows. A wire mesh is laid on the press platen, the molded body is placed on the wire mesh, the pressure plate is lowered, the pressure is raised to a predetermined pressure, and after holding for a predetermined time, the pressure plate is raised and the product is taken out. The applied pressure is preferably from 50 to 200 kg / cm ² . 200kg /
If it exceeds cm ² , the product is deformed by the pressure, which is not preferable. When it is less than 50 kg / cm ^2, the integration of the laminate is insufficient when producing the laminate, which is not preferable. FIG. 2 is a cross-sectional view of a molded body 5 obtained by molding a slurry. Pressing is performed on the molded body 5 obtained as described above.
May be performed for a single layer as shown in FIG. FIG. 3 is a cross-sectional view of a laminate in which a plurality of molded bodies 5 are stacked. As shown in FIG. 3, a plurality of molded bodies 5 may be stacked and pressed. FIG. 4 is a cross-sectional view of a laminated body in which a molded body 5 formed of a slurry and another shaped body 6 are combined.
In FIG. 4, as shown in A, the molded body 5 may be used as a core material and a fiber cement raw plate 6 may be laminated and pressed on both surfaces thereof, and as shown in B, two molded bodies 5 are stacked and further pressed. You may laminate | stack one fiber cement raw board 6, and may press it.
Use of the fiber cement green board 6 having no pores makes it possible to obtain an excellent composite panel having high strength.

In the pressed molded body, pores are formed inside by sublimating the sublimable substance. Therefore, the porosity of the obtained product is determined by the volume ratio of the sublimable substance in the material. To sublimate the sublimable substance,
The vaporization rate of these sublimable substances is not very high, and since the vaporization is suppressed because it is inside the molded body, the molded body is heated to increase the sublimation rate,
Further, a means such as reducing the pressure or making water vapor coexist is used. In the work, since these sublimable substances are often harmful to the human body and need to be recovered in terms of cost, heating must be performed in a closed space. In particular, harmful substances such as p-dichlorobenzene need to be sealed in a highly sealed device so as not to leak outside.

In addition, in the case of using a hydraulic material such as cement, it is necessary to cure the material. In the curing, heat curing or auto-grave curing is performed. It is preferable that the operation of sublimating the active substance is performed simultaneously with or before or after the above-mentioned curing. Curing includes autoclave curing, hot and humid curing, and natural curing, but natural curing is not practical due to time constraints. The curing reaction is accelerated by heating during curing, and a lightweight cured product can be produced in a short time, which is preferable. . For example, when using adamantane as a lightweight material,
Curing may be performed while heating to 70 to 100 ° C. When p-dichlorobenzene is used, it is preferable to carry out the reaction while heating to 50 to 60 ° C. When using autoclave curing or the like, it is necessary to prevent sublimation substances from being contained in wastewater or exhaust gas. Generally, such curing is
Perform for 6 hours.

According to the above method, since the molded body is pressed before curing, it is possible to discharge excess water and the like for the curing reaction. Therefore, it is possible to prevent the influence of the amount of moisture or the like on the scattered density in forming the holes, and it is possible to control the production of the holes only by adjusting the blending amount of the lightening material. In addition, a sublimable substance is used as the lightening material, so that a chemical change that is easily affected by pressure is not required for vaporization. Therefore, even under high pressure, the vaporization conditions are hardly affected. In addition, a substance having sublimability becomes a gas without passing through a liquid state. It is difficult for the weight-reducing material to move between the scattered portions during the period from almost no passage through the liquid state to vaporization, and if vaporized, the gas has a higher degree of expansion and flow than the liquid and has higher fluidity,
The scattered position of the sublimable substance is used as a hole as it is, and it is radiated without changing the position or shape.

[0024]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. (Example 1) Portland cement having an average particle size of 15 µm, silica powder having an average particle size of 6 µm, and an average fiber length of 1.
Using a 3-3.0 mm pulp and a hydrophilically treated adamantane having an average particle size of 30 μm, a lightweight cured product was obtained by the following method. In Examples 2 and below and in Comparative Examples, materials having the same quality and diameter as those of Example 1 were used for all materials below cement. First, adamantane powder, acrylic adhesive, and silica powder are kneaded at a weight ratio of 10: 0.1: 1, and the agglomerates or coagulated by the kneading are ground to an average particle size (15) μm. Then, an adamantane hydrophilized product subjected to hydrophilization treatment was obtained.

The hydrophilically treated adamantane thus obtained, cement, silica and pulp were mixed in the proportions shown in Table 1 and 10 parts by weight of the obtained mixture and water were mixed.
Water was mixed at a ratio of 15 parts by weight to obtain a slurry. From the slurry obtained in this way, a length of 30 c
A plate-shaped molded product having a size of mx 25 cm in width and 6 mm in thickness was obtained, pressed by a hydraulic press, cured while heating at 80 ° C for 3 hours, and adamantane was vaporized to obtain a lightweight cured product. Table 1 shows the physical properties of the obtained lightweight cured product.

(Example 2) An ethylene vinyl acetate resin was adhered to the surface of the same adamantane powder used in Example 1 with an acrylic adhesive to obtain a hydrophilically treated adamantane product. The mixing ratio of adamantane, adhesive, and ethylene vinyl acetate resin was 10: 0.1: 1. The hydrophilically treated adamantane, cement, silica and pulp were mixed in the proportions shown in Table 1, a slurry was formed from the mixture, and a 6 mm-thick plate was formed from the slurry by a papermaking method. After pressing the formed plate, it was heated and cured to sublimate adamantane to obtain a light-weight cured product. Table 1 shows the physical properties of the obtained lightweight cured product.

Example 3 A cement was adhered to the surface of p-dichlorobenzene powder with an acrylic adhesive to obtain a p-dichlorobenzene hydrophilically treated product. The mixing ratio of p-dichlorobenzene powder, vinyl acetate resin and cement is 10: 0.
It was set to 1: 1. The hydrophilically treated p-dichlorobenzene, cement, silica and pulp were mixed in the proportions shown in Table 1, a slurry was formed from the mixture, and a 6 mm thick plate was formed from the slurry by a papermaking method. 3
After stacking and pressing, heat curing was performed to sublimate p-dichlorobenzene to obtain a light-weight cured product. Table 1 shows the physical properties of the obtained lightweight cured product.

(Example 4) A compact having a thickness of 6 mm was obtained from the slurry in the same manner as in Example 1. On both sides of this board,
Cement, silica, and pulp were contained in the same ratio as in Example 1, and a 3 mm-thick plate molded using a slurry from a composition (blank) containing no sublimable substance was laminated, pressed, and then cured by heating. Then, adamantane was sublimated to obtain a composite plate. Table 1 shows the confirmed physical properties of the obtained composite plate.

Comparative Example 1 According to the method of Example 1, cement, silica, pulp, and adamantane were mixed in the proportions shown in Table 1, and the obtained mixture and water were mixed at 10 parts by weight of the mixture. , And 10 parts by weight of water to obtain a slurry in which the weight-reducing material has not been subjected to a hydrophilic treatment. Then, the slurry obtained in this manner is 30 cm long by the same papermaking method as in Example 1. × A plate-shaped molded product having a width of 25 cm and a thickness of 6 mm was obtained. Table 1 shows the confirmed physical properties of the molded product. (Comparative Example 2) A plate-shaped molded body having a thickness of 6 mm was obtained in the same manner as in Comparative Example 1, except that adamantane was changed to pearlite having an average particle size of about 13 µm (manufactured by Mitsui Mining & Smelting Co., Ltd.).

(Comparative Example 3) Three compacts having a thickness of 6 mm were manufactured in the same manner as in Comparative Example 2, and were laminated in three layers, pressed in the same manner as in Example 1, and cured by heating. To obtain a lightweight cured product. Table 1 shows the confirmed physical properties. Comparative Example 4 A molded product having a thickness of 6 mm was obtained in the same manner as in Comparative Example 1. Next, in the same manner as in Example 4, two plate-shaped molded bodies having a thickness of 3 mm were obtained with a blank compound containing no lightening material. In the same manner as in Example 4, the above-mentioned 3 mm molded body was laminated on both sides of the above 6 mm molded body as a core material, pressed, and heated and cured. Table 1 shows the confirmed physical properties. (Reference Example) In the same manner as in Example 4, a plate-shaped molded product having a thickness of 3 mm was obtained with a blank compound containing no lightening material. Table 1 shows the confirmed physical properties.

[0031]

[Table 1]

Note: Dispersion of the lightening material (representing the evaluation of the dispersion state of the lightening material in the slurry) ：: Good Δ: Dispersion is recognized temporarily. However, lightweight materials having a low specific gravity float and are gathered upward. ×: There is no dispersion and the surface is raised. Formation of pores (representing the formation and destruction of pores by pressing) ：: There is formation. No destruction. Δ: There is formation. In some cases it has been destroyed. ×: Destroyed. Void state (represents the possibility of pore dispersibility) ○: good △: partially defective ×: bad

From the above results, it was found that in all of Examples 1 to 4, the dispersion of the weight-reducing material in the slurry was good, and the pores were also good from the cross section of the manufactured lightweight cured product. It was also found that the specific gravity, bending strength, and peel strength against delamination also showed favorable values. On the other hand, in Comparative Example 1, the weight-reducing material was gathered upward in the slurry, and it was found that if cured, a local imbalance in specific gravity would occur. In Comparative Examples 2 to 4, sufficient dispersion of the weight-reducing material was not recognized, and it was found that when cured, qualitative non-uniformity in specific gravity occurred.

[0034]

According to the present invention, since the compact is pressed before curing, the scattered density of the pores is not affected by the amount of moisture or the like in forming the pores. Therefore, the formation of the holes can be controlled by the amount of the lightening material. During curing, it is difficult to move the scattered portion of the lightening material. If the material is vaporized, the scattered position becomes a hole as it is, and is radiated without deforming its shape. Therefore, it is difficult to form a continuous cavity in which pores are scattered at a substantially uniform density with a substantially uniform size and water droplets tend to stay. As a result, it is possible to produce a porous lightweight cured body that is resistant to frost damage, has no specific deviation in specific gravity, has high mechanical strength, is qualitatively uniform, and is capable of finishing the surface densely.

[Brief description of the drawings]

FIG. 1 shows an outline of a papermaking method.

FIG. 2 is a cross-sectional view of the lightweight cured body of the present invention.

FIG. 3 is a cross-sectional view of a laminated lightweight cured body of the present invention formed by stacking molded bodies.

FIG. 4 is a cross-sectional view of a laminated lightweight cured product of the present invention in which a molded product containing a lightening material according to the present invention and a fiber cement green board are stacked.

[Explanation of symbols]

 1 unit 2 Formwork 3 Mixer discharge port 4 Slurry 5 Molded body 6 Fiber cement raw board

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C04B 24/00 C04B 24/00 28/02 28/02 40/02 40/02 // C04B 103: 42 111: 40

Claims (4)

[Claims] Claims: 1. A light-weight cured material which is obtained by mixing a lightening material with a hydraulic material as a main raw material, adding water to form a slurry, and then giving a desired shape to obtain a molded product, and curing the molded product. In the production method, a substance having hydrophilicity and substantially sublimability is used as a weight-reducing material, and a molded body obtained by molding is pressed, and substantially before or during curing of the molded body. A method for producing a light-weight cured body, which comprises vaporizing a sublimable substance to make it porous. 2. The method according to claim 1, wherein the hydrophilic and substantially sublimable substance is adamantane subjected to a hydrophilic treatment. 3. The method according to claim 1, wherein the pressing is performed in a single layer or in a state of being laminated with another molded body. 4. The method according to claim 1, wherein vaporization of the substantially sublimable substance from the molded body is performed by curing at a temperature higher than the vaporization temperature of the substance. Manufacturing method of lightweight cured body.