JP2633788B2 - Method for manufacturing flexible fire-resistant building board - 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 manufacturing a fire-resistant building board which is flexible and can be curved.

[0002]

2. Description of the Related Art Recently, curved roofs are increasingly applied to buildings such as buildings. The curved roof has, for example, a structure in which a metal plate is laid on the upper side of a fire-resistant building board (field board) such as a fiber cement board. In this case, it is necessary to use a fire-resistant building board having a curved surface. Conventionally, in order to manufacture a fire-resistant building board having a curved surface, since this type of fire-resistant building board is poor in flexibility, a thin board that can be bent is bent, and a plurality of layers are stacked to a predetermined thickness. , A method of forming a plate having a curved surface using a molding die or the like (Japanese Patent Laid-Open No. 4-100258), and a method of joining curved narrow strip-shaped plates to form a curved surface.

[0003]

However, the method of bending a thin plate and stacking a plurality of layers requires a lot of labor for bending and lamination, and is not practical. The method of forming with a mold or the like has various radii of curvature. In order to form such a plate, various molds are required correspondingly, which is costly and reduces production efficiency. In addition, in the method of joining narrow strip-shaped plates, the curved surface shape becomes a polygonal shape, so that a good appearance cannot be obtained, and it takes time and effort to join.

[0004]

SUMMARY OF THE INVENTION According to the present invention, as a means for solving the above-mentioned conventional problems, a wooden fiber bundle which is made bulky by branching and / or bending and / or bending, a piece of wood, A mixture of cement and a curable inorganic powder mainly composed of a mixture of hollow or porous silicic acid-containing inorganic powder is formed into a plate-like shape under pressure, and is subjected to 60-80.
Preliminary curing at a temperature of 140 ° C.
The present invention provides a method for producing a flexible refractory building board which is subjected to autoclave curing in saturated steam of the above, wherein the wood fiber bundle used for the flexible refractory building board is 15 to 25% by weight based on the mixture, and the wood chips are based on the mixture. An object of the present invention is to provide a method for producing a flexible refractory building board mixed in a range of 5 to 10% by weight.

[0005] The present invention is characterized in that a wood fiber bundle is used as a reinforcing material. And in the present invention, the wood fiber bundle is a bundle of wood monofilaments, and the wood fiber bundle is made bulky by branching and / or bending and / or bending. In order to produce a wood fiber bundle which is bulked by branching and / or bending and / or bending, wood is immersed in a chemical solution such as caustic soda, sodium sulfite, calcium sulfite, or the wood is steamed. Heating or swelling without completely dissolving lignin, hemicellulose, resin, etc., which serves as a binder for woody single fibers contained in wood, by using the chemical solution immersion and steam heating together And defibrated by leaving the above-mentioned binder remaining, and has a larger diameter than pulp fibers defibrated by almost completely removing lignin, in particular, from the above-mentioned binder. And the wood fiber bundle has a diameter of about 0.3 mm.
It is preferably in the range of 1 to 2.0 mm and the length is in the range of about 2 to 35 mm, preferably in the range of 10 to 30 mm. In order to make the wood fiber bundle bulky by branching and / or bending and / or bending, the degree of swelling and the degree of defibration of the binder are adjusted. The defibration is performed, for example, with a grinding disk, and the degree of defibration is adjusted by adjusting the gap between the grinding disks.

The wood used in the present invention has a width of 0.5-2.
mm, length 1-20mm, aspect ratio (length / thickness) 2
The thing of 0-30 is desirable.

The curable inorganic powder used in the present invention is mainly composed of cement and one or more kinds of hollow or porous silicic acid-containing inorganic powders such as perlite, fly ash, shirasu balloon, diatomaceous earth and the like. However, blast furnace slag, bentonite and the like may be further added, and if desired, a hardening accelerator or a waterproofing agent such as calcium chloride, magnesium chloride, aluminum sulfate, sodium aluminate, and water glass may be added. .

[0008] The wood fiber bundle and the wood chips are mixed with the hardening inorganic powder. Usually, 50 to 60% by weight, preferably 55 to 58% by weight of cement is contained in the mixture, and hollow or porous silica is used. The content of the inorganic powder is 15 to 30% by weight, preferably 20 to 25% by weight, and when a curing accelerator is added, 0.4 to 1.0% by weight, preferably about 0.6 to 0.8% by weight. The wood fiber bundle is usually 15 to 2
5% by weight, and the above wood chips are usually added in an amount of about 5 to 10% by weight.

The above mixture is pressure-formed into a plate shape. In order to press-mold the mixture into a plate shape, the mixture is sprayed on a template to form a mat. In a continuous production method, a large number of the templates are placed on a belt conveyor. The mixture spread on the template is pressed slightly by a roll or the like, if desired, and the mat is then pressed and cured in the presence of moisture to obtain a desired shape. The amount of water to be added is usually 30 to 45% by weight in the above mixture. The above pre-curing is usually performed with a pressure of 10 to 20 kgf / c.
m ² , temperature 60 to 80 ° C., 12 to 24 hours, and heating is usually performed with steam. Pressing is performed by clamping the mat between two mold plates, but the mold plate surface may be given a predetermined shape, an uneven pattern, or the like.

The preformed body formed by the above precuring is then cured in an autoclave. The autoclave curing is usually performed at a pressure of 2.7 to 3.9 kgf / cm ² ,
The reaction is carried out at a saturation temperature of 140 to 150 ° C. for 8 to 24 hours, preferably 8 to 15 hours. Thus, the flexible fire-resistant building board of the present invention is obtained.

[0011]

The wood fiber bundle used in the flexible refractory building board of the present invention is made bulky by branching and / or bending and / or bending, so that the fiber bundle is obtained in the matrix of the obtained product. The wood fiber bundles are firmly entangled over a certain distance, and a flexible and high-strength product is obtained by such a specific reinforcing effect.
However, when the wood fiber bundle alone is used, the mixing and dispersibility when mixed with the curable inorganic powder deteriorates due to the entanglement. Therefore, the addition of wood chips improves the mixing and dispersibility of the mixture. In the curable inorganic powder of the present invention, a hollow or porous silicic acid-containing inorganic powder is added to cement, but when the hollow or porous silicic acid-containing inorganic powder is used, conventional silica sand or silica powder such as silica powder is used. It was found that the bending Young's modulus of the product was reduced by about 20% as compared with the contained inorganic powder. In the present invention, the autoclave curing temperature is further increased to 150 ° C.
Deterioration of the wood fiber bundle, which is a reinforcing material, is suppressed to the following, but at less than 140 ° C., hardening of the hardenable inorganic powder does not occur smoothly.

[0012]

【Example】

Example 1 A piece of woody fiber immersed in a sodium sulfite solution and swelled in volume was further heated by steam, and furthermore, a bulky wood fiber bundle (diameter of 0.5 to
(1.5 mm, length 10 to 30 mm) 9.6% by weight, and wood chips obtained by cutting wood chips into pieces having a width of 0.5 to 2 mm, a length of 1 to 20 mm, and an aspect ratio of 20 to 30 using a Pearlman Flaker. 8% by weight. Portland cement 5
6.8% by weight and 24.8% by weight of fly ash were mixed and wet-mixed with the wood reinforcing material, and magnesium chloride as a hardening accelerator was added in an amount of 0.4% based on the total solid content.
% By weight, and added water in which a paraffin emulsion as a waterproofing agent is dissolved at 0.2% by weight based on the total solid content is added at a ratio of 36% by weight based on the total solid content, and the mixture is uniformly stirred and mixed to obtain a wet mixture. And The wet mixture was sprayed on a lower mold plate to form a mat having a thickness of 100 mm. The upper mold plate was brought into contact with the mat and pressed at a pressure of 35 kgf / cm ^2. Pre-curing by heating for hours. The obtained molded body was a plate-like body having a thickness of 18.0 mm, and the molded body was thereafter subjected to a pressure of 3.25 kgf / cm ² G and a saturated steam temperature of 145 ° C.
Autoclave curing for 8 hours under the conditions described above. Table 1 shows the measurement results of the physical properties of the test plate A thus obtained.

Comparative Example 1 A wet mixture was prepared using the bulky wood fiber bundle described in Example 1 and a piece of wood at the following mixing ratio. The wet mixture was pre-cured in the same manner as in Example 1 to obtain a plate-like body, and the plate-like body was subjected to autoclave curing at a pressure of 6.2 kgf / cm ² G and a saturated steam temperature of 165 ° C. for 8 hours. Table 1 shows the measurement results of the physical properties of the test plate B thus obtained.

COMPARATIVE EXAMPLE 2 A wood chip cement board was manufactured from the wood piece of Example 1 in accordance with the conventional manufacturing method at the following compounding ratio. The wet mixture was pre-cured in the same manner as in Example 1 to obtain a plate, and the plate was stacked and naturally cured for 7 days to obtain a test plate C. Table 1 shows the measurement results of the physical properties of the test plate C.

[0015]

[Table 1]

*: Physical properties were determined by measuring the relationship between load and deflection using a computer-measured and controlled precision universal testing machine (Shimadzu Autograph AGS-500A). The test is 500mm long and 40mm wide for A, B and C.
The dimensions were 0 mm and the thickness was 18 mm. Graphs showing the relationship between the load and the amount of deflection are shown in FIG. 1 (test plate A), FIG. 2 (test plate B), and FIG. 3 (test plate C). **: Energy (bending work) is obtained by integrating the graphs of FIGS. 1, 2 and 3, respectively, and the greater the amount of energy, the greater the flexibility.

According to Table 1, the test plate A of the present invention has a thickness of 18
In contrast to the test plate B autoclaved at a high temperature of 150 ° C. or more, the test plate B can be bent to a thickness of 18 mm and a radius of curvature of 9 m. The test plate C using only the powder and not using the hollow or porous silicic acid-containing inorganic powder was bent to a thickness of 18 mm and a radius of curvature of 14 m.

[0018]

Accordingly, in the present invention, it is possible to obtain a flexible fire-resistant building board which can be bent with a small radius of curvature and is useful as a fire-resistant base plate for a curved roof.

[Brief description of the drawings]

FIG. 1 is a graph of load-deflection amount of a test plate A.

FIG. 2 is a graph of load-deflection amount of a test plate B.

FIG. 3 is a graph of load-deflection amount of a test plate C;

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication (C04B 28/16 16:02 18:26)

Claims (2)

(57) [Claims] 1. Hardening based on a mixture of wood fiber bundles, wood chips, cement and hollow or porous silicic acid-containing inorganic powder, which are made bulky by branching and / or bending and / or bending. The mixture is formed into a plate-like mixture with the inorganic powder under pressure, preliminarily cured at a temperature of 60 to 80 ° C, and then subjected to autoclave curing in saturated steam at 140 to 150 ° C. Manufacturing method of fire-resistant building board 2. The wood fiber bundle is added to the mixture in an amount of 15 to 25.
The method for producing a flexible fire-resistant building board according to claim 1, wherein the wood chips are mixed with the mixture in a range of 5 to 10% by weight.