JP3448121B2 - Manufacturing method of lightweight inorganic plate - Google Patents

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 inorganic plate containing xonotlite as a main component.

[0002]

2. Description of the Related Art Conventionally, a lightweight inorganic plate containing xonotlite as a main component has been provided. The lightweight inorganic plate is made by heating and reacting a slurry in which a siliceous raw material and a calcareous raw material are dispersed under water to generate zonotlite, and the slurry of the zonotolite is subjected to paper-making dehydration molding, and the molded product is heated and dehydrated and dried. Was manufactured by the method
5-25771, etc.).

[0003]

However, in the above-mentioned prior art, in order to obtain a desired product strength, a fiber reinforcing material is added in an amount of about 8% by weight, and the siliceous raw material and the calcareous raw material are hardened. In order to proceed the reaction, it must be heated to a high temperature of 150 ° C. Therefore, if a fiber reinforcing material having low heat resistance is used, the reinforcing effect is lost due to the above heating, and the reinforcing effect is lost. If one is used, the water resistance of the product will deteriorate. However, there is a problem that the fiber reinforcing material which is excellent in heat resistance and has no hygroscopicity is very expensive and the raw material cost becomes high.

[0004]

Means for Solving the Problems As a means for solving the above-mentioned conventional problems, the present invention comprises heating a slurry obtained by dispersing raw materials mainly composed of a siliceous raw material and a calcareous raw material in water under pressure. At the very least, a slurry containing xonotlite as a main component is prepared, and an alkali-curable inorganic substance containing active SiO ₂ is further added to and mixed with the slurry for paper-making dehydration molding, and the resulting molded product is cured by curing. A method for manufacturing a lightweight inorganic plate is provided. The present invention is described in detail below.

[Silicic material] Examples of the silicic material used in the present invention include silicic acid, amorphous silicic acid, silica sand, silica stone powder, diatomaceous earth, quartz, feldspars, clay minerals, slag, It is a raw material containing SiO ₂ as a main component, such as clay, fly ash, perlite, and vermiculite.

[Calcium Raw Material] The calcareous raw material used in the present invention is a raw material containing CaO as a main component, such as slaked lime, quick lime, and carbide slag.

[Production of Zonotolite] The above siliceous raw material and calcareous raw material are dispersed in water to form a slurry, and when the slurry is heated with stirring under pressure, calcium silicate reaction produces xonotlite in the slurry. . In the xonotlite formation reaction, the molar ratio of CaO contained in the SiO ₂ and calcareous material contained in the siliceous material [SiO _2] / [CaO] is usually 7: 3 to 3: is a 7 range, the slurry The solid content concentration is usually about 10 to 40% by weight, the reaction is usually carried out with stirring in an autoclave, and the pressure is 10 to 20%.
kg / cm ^2, the temperature is set to about 170 to 220 ° C., the reaction time is usually about 7 to 12 hours.

[Alkali Curable Inorganic Material Containing Active SiO ₂ ] The zonotolite slurry prepared as above is
Although alkaline curable inorganic substance containing an active SiO ₂ is added as the alkaline-curable inorganic material containing said active SiO _2, for example blast furnace slag, blast furnace cement, fly ash, ones containing active SiO ₂ such as silica fume Quality is used. Alkaline curable inorganic material containing said active SiO ₂ is added usually about 20 to 50 wt% with respect to the slurry solids.

[Third Component] The above-mentioned slurry contains fillers such as perlite, gypsum powder, calcium carbonate, magnesium carbonate, and wood cement board waste powder, pulp, wood fibers, wood chips, wood reinforcing materials such as wood wool, and polyester. Reinforcing materials such as fibers, polyamide fibers, acrylic fibers, acetate fibers, organic fibers such as cotton fibers, glass fibers, ceramic fibers, inorganic fibers such as rock fiber, and metal fibers may be added. In the present invention, the above-mentioned filler is usually added in an amount of about 3 to 20% by weight in the solid content of the slurry, and the reinforcing material is obtained in an amount of 10% by weight or less in the solid content of the slurry to obtain a product having sufficient strength.

[Papermaking] Papermaking is carried out by a method using a known apparatus such as a flow-on system, a Hatschek system, a batch system, and the solid content concentration in the slurry is usually adjusted to about 5 to 15% by weight during papermaking. To be done. Then, the formed mat is dehydrated by vacuum suction or pressing, and if desired, a predetermined number of the mat may be laminated using a making roll or the like.

[Press Molding] The above-mentioned paper-made mat is molded into a predetermined shape by press molding if desired. The molding pressure in this case is usually 5
~ 30 kg / cm ² .

[Curing curing] The above-mentioned paper-formed and preferably molded article is cured. The curing condition is usually 50 to 80 ° C. for 6 to 15 hours. Of course, when the curing temperature is low, the curing time becomes long.
In the curing step, the alkali activated SiO ₂ contained in <br/> alkaline curable inorganic material containing an added active SiO ₂ eluted from calcareous material in the slurry, silicate reacts mainly Ca ⁺⁺ ions It forms calcium acid or calcium aluminate gel and hardens. After curing, the product is usually dried by heating at 80 to 120 ° C. for about 2 to 5 hours to obtain a product.

[0013]

When a slurry in which raw materials mainly composed of siliceous raw material and calcareous raw material are dispersed is heated under pressure, zonotlite is produced in the slurry by a calcium silicate reaction. In the xonotlite slurry thus obtained, the alkali, mainly C, eluted from the calcareous raw material was used.
Since the a ⁺⁺ ion is contained in the slurry, the active Si
The addition of alkaline curable inorganic material containing O _2, the active
Si in Alkali Curable Inorganic Material Containing Stable SiO ₂
O ₂ reacts with Ca ⁺⁺ to form a calcium silicate gel and hardens. The above curing reaction mainly proceeds during the curing step of the molded product after the slurry is subjected to paper-making dehydration molding. Therefore, the strength of the inorganic plate of the present invention is expressed by the calcium silicate cured product based on the reaction between the alkali-curable inorganic substance containing active SiO ₂ and the dissolved alkali in addition to the entanglement of xonotlites with each other. A lightweight inorganic plate can be obtained without adding a large amount of aggregate or the like.

[0014]

EXAMPLES Example 1 Silica stone powder and slaked lime are dispersed in water to prepare a slurry having a solid content concentration of 30% by weight. The mixing ratio of the silica stone powder and slaked lime is such that the molar ratio of SiO ₂ contained in the silica stone powder and CaO contained in the slaked lime is 5: 5. The slurry was placed in an autoclave under a pressure of 15 kg / cm ² for 20
Heat to a temperature of 0 ° C. and stir for 9 hours. By this reaction, SiO ₂ of silica stone reacts with CaO of slaked lime to produce zonotolite, and a calcium silicate reaction intermediate product is present in the slurry. Blast furnace slag is added as an alkali-curable inorganic substance containing active SiO ₂ to the xonotlite slurry, and perlite as a filler and pulp as a fiber reinforcement are added to prepare a slurry having a solid content concentration of 10% by weight. The composition of the solid content in the slurry is as follows. Zonotolite 57 wt% Blast furnace slag 30〃 Pulp 3〃 Perlite 10〃 The above-mentioned mixed slurry is made into a mat by dewatering with a Hatche type paper machine, and the mat is pressed at a pressure of 15 kg / cm ² to be formed into a predetermined shape. . The above-mentioned paper-making dehydration-molded product is aged at a temperature of 60 ° C. for 12 hours, and active SiO ₂ contained in the blast furnace slag reacts with Ca ⁺⁺ ions eluted from the reaction intermediate product during the curing process. It becomes a calcium silicate gel and hardens. After curing, it is dried by heating at 120 ° C for 4 hours. Thus, a lightweight inorganic plate having a specific gravity of 0.30 and a bending strength of 47 kgf / cm ² is manufactured.

Example 2 A lightweight inorganic plate is manufactured in the same manner as in Example 1 except that fly ash is used instead of the blast furnace slag of Example 1. The specific gravity of the obtained lightweight inorganic plate was 0.28, and the bending strength was 39 kgf / cm ² .

Example 3 A lightweight inorganic plate is manufactured in the same manner as in Example 1 except that silica fume is used instead of the blast furnace slag of Example 1. The specific gravity of the obtained lightweight inorganic plate was 0.40, and the bending strength was 51 kgf / cm ² .

[0017]

Therefore, in the present invention, since the strength of the xonotlite-based inorganic plate is reinforced by the alkali-curable inorganic substance containing active SiO ₂ , it is not necessary to add a large amount of fiber reinforcing material or lightweight aggregate. Any kind of fiber reinforcement can be used, resulting in a lightweight and inexpensive inorganic board.

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Claims (2)

(57) [Claims] 1. A slurry containing xonotlite as a main component is prepared by heating and reacting a slurry prepared by dispersing raw materials mainly composed of a siliceous raw material and a calcareous raw material in water under pressure.
A method for producing a lightweight inorganic plate, characterized in that an alkali-curable inorganic substance containing active SiO ₂ is further added to and mixed with the slurry for paper-making dehydration molding, and the resulting molded product is cured and cured. 2. A method for producing a lightweight inorganic board according to claim 1 alkaline curable inorganic material containing said active SiO ₂ is selected from the group of blast furnace slag, blast furnace cement, fly ash and silica fume