JPH03131554A - Inorganic formed article and production thereof - Google Patents

Abstract

PURPOSE:To obtain an inorganic formed article having light weight, high strength and excellent dimensional stability by sprinkling a mixture of a bulky wooden fiber bundle and a curable inorganic powder on a template to form a mat, pressing the mat and hardening the pressed mat in the presence of water content and curing the hardened mat. CONSTITUTION:A mixture of a wooden fiber bundle and a curable inorganic powder made bulky by branching and/or warping and/or bending is sprinkled on a template to form a mat. Then the mat is pressed and hardened in the presence of water content and then cured in an autoclave to provide the aimed formed article. The wooden fiber bundle made bulky can be produced by dipping wood into a chemical such as sodium hydroxide, sodium sulfite, calcium sulfite, etc., or using the above-mentioned chemical dipping and a steam heating together while only swelling lignin, hemicellulose, resin, etc., serving as a binder of wooden single fiber contained in wood without completely dissolving these ingredients and opening the wood while leaving the binder.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inorganic molded body made of a mixture of wood fiber bundles and curable inorganic powder, and a method for producing the same.

[Conventional technology]

BACKGROUND ART Inorganic molded bodies mainly composed of hardening inorganic powder such as cement are used as, for example, architectural board materials such as exterior wall materials, interior wall materials, and roofing materials.

This type of inorganic molded body includes a wood chip cement board in which wood chips are mixed as a reinforcing material (Special Publication No. 39-12950).
. A wood chip is a shaving of wood, usually 20 to 50 mm in length.
, width 1.0~6.0mm, thickness 0.1~1.0LlI+
It is in the form of flakes of about 1.5 mm in size, and is present in the inorganic molded body to act as a binder, give flexibility to the inorganic molded body, and make it lightweight.

[Problem to be solved by the invention]

However, when wood chips are used as reinforcing materials, there is little expectation that the wood chips will intertwine with each other, so the reinforcing effect is not sufficient, and therefore the density of the product cannot be increased by increasing the compression force during molding. and sufficient strength cannot be obtained. However, increasing the density of the product makes it heavier, making it difficult to carry and nail. In order to obtain sufficient strength without increasing the density of the product, it is necessary to increase the amount of wood chips added. However, there was a problem in that if the amount of wood chips added was increased, the nonflammability of the product would decrease.

Inorganic molded bodies mixed with pulp fibers, which are more easily entangled in shape than wood chips, are also available as reinforcing materials, but the reinforcing effect of pulp fibers is not sufficient, and it is necessary to mix asbestos or synthetic fibers ( JP-A-63-256560, JP-A-63-256561, JP-A-56-63858).

However, even if asbestos or synthetic fibers are mixed with pulp fibers, these fibers are not bulky, so in order to obtain a product that is lightweight and has satisfactory strength, it is still necessary to add a large amount of fiber. However, increasing the amount of these fibers added increases the material cost, and increasing the amount of pulp fibers or synthetic fibers decreases the nonflammability of the product. Although asbestos is nonflammable, it is easily dispersed into the air and has severe restrictions on its use as a harmful substance to the human body.

In addition, as an efficient method for manufacturing this type of inorganic molded body, a dry manufacturing method is used in which a mixture of curable inorganic powder and reinforcing material is spread on a template to form a mat, and the mat is press-formed. Recommended. In this dry manufacturing method, it is necessary that the mixture of the curable inorganic powder and the reinforcing material described in "2" be easily spread evenly over the template, and that the mat formed on the template be difficult to lose its shape. Ru. However, when using wood chips as a reinforcing material, there is almost no entanglement as mentioned above, and unless the amount of wood chips added is large, the mat formed on the template-1- is very likely to lose its shape. When using pulp fibers or mixed fibers in which asbestos or synthetic fibers are mixed with the pulp fibers, when mixed with the curable inorganic powder, the mixture becomes entangled in a ball-like shape, making it difficult to unravel the mixture. It becomes very difficult to spread evenly.

[Means to solve the problem]

The present invention provides five means for solving the above-mentioned conventional problems.
Inorganic molding in which a mixture of wood fiber bundles made bulky by branching and/or curving and/or bending and curable inorganic powder is molded into a predetermined shape and the curable inorganic powder is cured. It provides the body,
The inorganic molded body is obtained by uniformly spreading a mixture of the wood fiber bundle and curable inorganic powder onto a template to form a mat, compressing the mat to harden it in the presence of moisture, and then curing it in an autoclave. Manufactured by

The present invention is characterized by using wood fiber bundles as the reinforcing material. In the present invention, the wood fiber bundle is a bundle of wood single fibers, and the wood fiber bundle is made bulky by branching and/or composing and/or bending. To produce wood fiber bundles made bulky by branching and/or curving and/or bending, wood is immersed in a chemical solution such as caustic soda, sodium sulfite, calcium sulfite, etc., or the wood is heated with steam. The lignin, hemicellulose, resin, etc. that act as binders for the wood filaments contained in the wood are not completely dissolved by heating, or by using a combination of chemical immersion and steam heating. It is a pulp fiber that is only swollen and then defibrated while leaving the binder, and has a larger diameter than pulp fiber that is defibrated after almost completely removing the binder, especially lignin. The diameter of the wood fiber bundle is approximately 091~2°0.
The length is in the range of about 2 to 35 mm, preferably in the range of 10 to 30 mm.

In addition, if the wood fiber bundle is branched, the diameter of the wood fiber bundle before branching is in the range of approximately 0.1 to 2.0 mm, and the wood fiber bundle is curved and/or folded. If it is bent, the length refers to the actual length of the wood fiber bundle, not the distance between the ends.

The wood fiber bundle is bulky due to the above size and shape, and its bulk specific gravity is approximately 0.03 to 0.05 g/f.
It is in the fl range. Here, the bulk specific gravity is 80 in inner diameter and 20 in volume.
00 m] filled with 2000 ml of the wood fiber bundle in an absolutely dry state, the total weight was measured, and the weight of the wood fiber bundle was determined by subtracting the weight of the graduated cylinder from the total weight. A disk that fits exactly within the inner diameter of the wood fiber bundle is placed on top of the filled wood fibers, a weight is placed on the disk, and a weight of 1 kg is applied to the wood fiber bundle, and the volume of the wood fiber bundle is measured; It is determined by dividing the weight (g) of the wood fiber bundle by the volume (d).

By branching and/or curving and/or bending the wood fiber bundle, the degree of swelling and fibrillation of the binder can be adjusted to make it bulky and slimy. Defibration is carried out using, for example, a grinding disc, and the degree of defibration is adjusted by adjusting the disc gap of the grinding disc.

Curable inorganic powders used in the present invention are inorganic powders that harden through hydration reactions such as cement and gypsum, calcium-containing inorganic powders such as cement and gypsum, and silicic acids such as silica sand, silica stone powder, silica hume, and shirasu balloon. These include mixed inorganic powders that harden through a calcium silicate reaction, such as a mixture with a containing inorganic powder, and inorganic powders that harden through crystal dislocation, such as magnesium carbonate.

The wood fiber bundles and the curable inorganic powder are mixed, and in the case of a dry manufacturing method, the mixture is sprinkled on a template, and the wood fiber bundles in the mixture usually weigh 5 to 25% % is added.

Furthermore, inorganic fillers such as perlite, bentonite, blast furnace slag, rice ash, fly ash, diatomaceous earth, and organic fillers such as synthetic resins, synthetic resin foams, wood chips, and wood powder may be added, and curable inorganic powders may also be added. When the body is cement, hardening accelerators such as magnesium chloride, calcium chloride, aluminum sulfate, water glass, etc. may be added.

The above examples are not intended to limit the invention.

The above-mentioned mixture is spread onto a mold plate to form a mat, and in a continuous production method, a large number of the above-mentioned mold plates are placed on a belt conveyor. The mixture spread on the template is pressed slightly, if desired, with a roll or the like, and the mat is then compacted and hardened in the presence of moisture to form the desired shape. The amount of water added is usually 30 to 45% by weight in the above mixture.
be included. The clamping conditions are usually clamping pressure 10-20
Kg/cj, at a temperature of 60 to 80°C, for about 20 to 30 hours, and heating is usually performed with steam. The pressing is performed by pressing the mat between two templates, but the template surface may be provided with a predetermined shape, uneven pattern, etc.

The inorganic molded article of the present invention is usually molded into a plate shape, but may be molded into a block shape or the like if desired.

After the inorganic molded article of the present invention is pressed and hardened, it is cured in an autoclave if desired. Curing conditions are usually pressure 10-2.
0 kg/ad, temperature 160-180°C.

The time is 5 to 10 hours.

The autoclave curing described above is not necessarily essential, and natural curing may be performed.

In this way, the inorganic molded article of the present invention is obtained.

[Effect]

The wood fiber bundles used in the inorganic molded article of the present invention are made bulky and sewn by branching and/or bending and/or bending, so when mixed with the curable inorganic powder, the fiber bundles are The fiber bundles become entangled over a certain distance, but since the fiber bundles have a larger diameter than the pulp fibers, they have a certain degree of rigidity and do not become entangled in a ball-like shape.
In this way, the curable inorganic powder is trapped between the intertwined fiber bundles. The above-mentioned rigidity of the fiber bundles helps maintain the distance between the fiber bundles and thereby maintain the bulk. Therefore, when a dry manufacturing method is applied to the production of the inorganic molded body of the present invention, the mixture of the curable inorganic powder and the wood fiber bundles can be loosened by mechanical stirring, etc., and the mixture can be spread uniformly on the template. On the other hand, after scattering, the curable inorganic powder is entangled with the wood fiber bundles over a certain distance, creating a mat that does not lose its shape. can be formed.

In products, the wood fiber bundles in the matrix have a unique reinforcing effect in which the fiber bundles are tightly intertwined with each other at a certain distance as described above, resulting in a lightweight and high-strength inorganic molded body with a low specific gravity. It gives. Further, in the production of the inorganic molded body of the present invention, autoclave curing is performed after pressing, and the curing reaction of the curable inorganic powder is almost completely completed during the autoclave curing. Therefore, the curing reaction of the curable inorganic powder hardly progresses in the product, and dimensional changes in the product due to the curing reaction are avoided.

〔Effect of the invention〕

Therefore, in the present invention, it is possible to obtain an inorganic molded body that is lightweight, has high strength, and has extremely good one-dimensional stability, and it is possible to produce the inorganic molded body by a dry manufacturing method. The product is easy to obtain.

Furthermore, since the wood fiber bundle of the present invention has a large reinforcing effect, even if the amount added is 25% by weight or less, a molded product with sufficiently high strength can be obtained, and therefore a molded product with excellent nonflammability can be obtained.

〔Example〕

Examples 1 to 10 Mix the following composition using a mixer.

Cement: 47% by weight Silica sand: 30 Perlite: 10 Wood fiber bundles: 10 Aluminum sulfate: 3 The above-mentioned wood fiber bundles are branched and/or curved and/or bent and have the following dimensions and bulk specific gravity.

Examples Average diameter (mm) Average length (mm) Bulk specific gravity (g
/J) 1 0.10 20 0.0482
0.50 20 0.0463 1.
00 20 0.0424 1.50
20 0.0395 2.00 20
0.0366 0.80 10 0
．． 0457 0.80 15 0.043
8 0.80 20 0.0429
0.80 25 0.0401
0 0.80 30 0.
038 Add water to the above mixture to reduce the water content to 40% by weight, and then sprinkle it on the lower template to form a mat with a thickness of 55 mm.
The upper mold plate was brought into contact with the mat at a pressure of 10 kg/cm3,
Press hardening is performed at a temperature of 70° C. for 25 hours.

The obtained molded body is a plate-shaped body with a thickness of 151 m, and the molded body is then placed in an autoclave at a pressure of 15 kg/cm3.
, and cured for 7 hours at a temperature of 165°C.

In this way, molded bodies 1 to 1o are obtained.

Comparative Examples 1 to 8 A molded article 1 was produced in the same manner as in Examples 1 to 10 using branched and/or curved and/or bent wood fiber bundles having the following dimensions and bulk specific gravity.
1 to 18 are obtained.

Comparative example average diameter (mm) average length (mm) bulk specific gravity (g
/a()1 0.06 20 0.050
2 0.08 20 0.0493 2
．． 20 20 0.0334 2.40
20 0.0305 0.80
6 0.0466 0.8
0 8 0.0457
0.80 32 0.038
8 0.80 34 0
．． 036 The spraying workability, deformability of the mats, and the specific gravity and bending strength of the molded bodies 1 to 18 of the above examples and comparative examples were measured. The results are shown in Tables 1 and 2.

In addition, the shape deformability of the mat is determined by measuring the lower template on which the mat is placed.
Check whether the mat loses its shape when the mat is moved up and down three times with a stroke of m and a cycle of 1 second.

Spraying workability Example 1 Good 2 Good 3 Good 4 Good 5 Good 6 Good 7 Good 8 Good Good No deformation No No No No No No No No No No Good No No Good No Easy to unravel None Slightly difficult to come apart None Good Slightly good Slightly good Good Somewhat difficult to come apart None Hard to come apart None Table 1 Specific gravity (g/a&) Bending strength (Kgf/cJ) 1.00
80 0.98 75 0.96 70 0.93 65 0.90 60 0.97 65 0.97 65 0.97 70 9 0.96 75 10 0.96 80 11 1.10 80 12 1.05 80 13 0.85 45 14 0.80 40 15 0.97 50 16 0.97 55 17 0.96 55 18 0.96 50 Table 2 Referring to Table 1 above, the average diameter is 0.1 to 2.0 mm, and the length is Branches and /
or Examples using curved and/or bent wood fiber bundles] ~1o is easy to loosen the mixture, easy to spray, and the formed mat does not lose its shape, and is suitable for dry manufacturing method. It is understood that the wood fiber bundles described above are extremely useful. On the other hand, in Comparative Examples 1 and 2 using wood fiber bundles with an average diameter of 0 or 1 n++a or less, or Comparative Examples 7 and 8 using wood fiber bundles with an average length of 301 or more, the entanglement of the wood fiber bundles was thread-like. This causes problems in spraying workability. Also, the average diameter is 2.0
In Comparative Examples 3 and 4, which used wood fiber bundles of III+ or higher, or Comparative Examples 5 and 6, which used wood fiber bundles with an average length of 10 mm or less, the strength of the mat was poor because the wood fiber bundles were not sufficiently intertwined. Therefore, when the wood fiber bundles of Comparative Examples 1 to 8 are used, it is difficult to apply the dry manufacturing method.

Also, referring to Table 2 above, the average diameter is 0, ], mm
Molded bodies 11 and 12 using the following wood fiber bundles have a specific gravity of >- or more, and molded bodies 13 and 14 using wood fiber bundles with an average diameter of 2.0 mm or more, or an average length of 101 or less. In the molded bodies 15 and 16 using the wood fiber bundles, the wood fiber bundles are insufficiently intertwined and the bending strength is reduced. Furthermore, it can be seen that even when the average length of the wood fiber bundles is 30 mm or more, uneven distribution occurs as in the case of molded bodies 17 and 18, and as a result, a molded body with a uniform structure cannot be obtained, and the 1 bending strength is reduced.

Example 11 Average diameter 1. Omm, average length 1.8mm, bulk specific gravity 0.0
The following composition is mixed in a mixer using a branched and curved wood fiber bundle of 40 g/i.

Cement 50% by weight Rice ash 20 Diatomaceous earth 10 Wood fiber bundle 15 Calcium chloride 5 Water was added to the above mixture to make the water content 35% by weight, and then sprinkled on the lower mold board to form a mat with a thickness of 751 cm. The upper template was brought into contact with the mat at a pressure of 15 kg/cm3 and a temperature of 75 kg.
Press hardening is performed at ℃ for 30 hours.

The obtained molded body was a plate-shaped body with a thickness of 20III+, and the molded body was then placed in an autoclave at a pressure of 17K.

/cm3 and cured for 8 hours at a temperature of 170°C.

In this way, a molded body 19 is obtained.

Example 12 Average diameter 1.5n+m, average length 15mm, bulk specific gravity 0.0
The following composition is mixed using a mixer using a curved or bent wood fiber bundle of 40 g/cxl.

Cement 45% by weight silica
30 Fly ash
10 Wood fiber bundle 1o
〃Polystyrene-subexpanded beads 10 〃Calcium chloride 211 Water was added to the above mixture to make the water content 40% by weight, and then sprinkled on the lower template to form a mat with a thickness of 90 mm, and the upper template was placed on the mat. They are brought into contact and pressed and hardened at a pressure of 20 kg/cm3 and a temperature of 70°C for 25 hours.

The obtained molded body is a plate-shaped body with a thickness of 25 mm. The molded body was then placed in an autoclave under a pressure of 15 kg/cm3.
, and cured for 7 hours at a temperature of 175°C.

Due to the above curing, the polystyrene foam beads undergo secondary foaming to become polystyrene foam spherules, and the polystyrene foam spherules further melt, leaving behind bubbles and the melted polystyrene foam spherules cover the walls of the bubbles. do.

In this way, a molded body 20 is obtained.

Comparative Example 9 In the composition of Example 1, the wood fiber bundles had an average diameter of 0.08.
mm, average length 18 mm, bulk specific gravity 0.059 g/cm3
A molded body 21 is produced in the same manner except that the pulp fibers 7, the polyester fibers having a thickness of 2 denier and a length of 15 mm are replaced with 3 parts by weight of mixed fibers, but in the mixture, the pulp fibers and the polyester fibers are Compared to Example 11, it was difficult to uniformly spread the mixture on the lower template because the mixture was entangled in a ball-like shape.

Comparative Example 10 In the composition of Example 11, the wood fiber bundle was 1-OPaI1
Thickness passing through 1 mesh 0.4 ~ ]-0OIII+,
A molded body 22 is produced in the same manner except that a piece of wood having a bulk specific gravity of 0°095 g/ffl is used. Since the wood chips were hardly entangled in the mixture, it was easy to mix them uniformly by mechanical stirring, and it was easy to uniformly spread the mixture on the lower template.

Tests Examples 11, 1.2 and Comparative Example 9 above. ] The deformability of the mat of No. o, and the specific gravity and bending strength of molded products 19 to 22 were measured. The results are shown in Table 3. According to Table 3, in Examples 11 and 12, the mats do not lose their shape, but in Comparative Example 9, even when polyester fibers are mixed, some deformation is observed.

Also, Example 11. , 12 are clearly lighter and stronger than the molded bodies 21 and 22 of Comparative Examples 9 and 10.

In addition, the mechanical strength of the molded body 22 is extremely weak and cannot be put to practical use. In order to have the same strength as Example 11.12, that is, the bending strength of 70 kgf/a (about 70 kgf/a), it is necessary to add wood chips to about 30% by weight and increase the compaction pressure to about 30 kg/ci. However, increasing the amount of wood chips added deteriorates the nonflammability of the molded product, and increasing the compaction pressure increases the specific gravity of the molded product to about 1.3, making it heavier, making it difficult to obtain a lightweight and high-strength product. I can't do it.

Comparative Example 11 In place of the wood fiber bundle in Example 1, an unbranched linear wood fiber bundle having an average diameter of 0.10 m, an average length of 20IIi11, and a bulk specific gravity of 0.054 g/cm was used, and the same procedure as in Example 1 was carried out. The molded body 23 obtained by this process has a specific gravity of 1.20 g/i and a bending strength of 60 kg.
f/cJ, and the specific gravity is higher than that of molded product 1 described in Table 1, but the strength is inferior.

Comparative Example 12 In place of the wood fiber bundle of Example 5, a branched and/or curved and/or bent wood fiber bundle with an average diameter of 2.3 m, an average length of 20 nn, and a bulk specific gravity of 0.027 g/ci The molded body 24 obtained in the same manner as in Example 5 had a specific gravity of 0.
．． 86g/crj, bending strength 45Kgf/ci,
The strength is inferior to molding pair 5 listed in Table 1.

Claims (1)

[Claims] 1. A mixture of a wood fiber bundle made bulky by branching and/or curving and/or bending and a curable inorganic powder is molded into a predetermined shape, and the curable inorganic An inorganic molded body 2 characterized by hardening powder, the wood fiber bundle having a diameter of 0.1 to 2.0 mm and a length of 2
The inorganic molded body 3 according to claim 1, which has a bulk density of 0.03 to 0.05 g/c and the wood fiber bundle has a diameter of 0.03 to 0.05 g/c.
The inorganic molded body 4 according to claim 1, which has a range of m^3, a mixture of a wood fiber bundle made bulky by branching and/or curving and/or bending and a curable inorganic powder. A method for producing an inorganic molded body, which comprises: scattering on a template to form a mat, compressing the mat and curing it in the presence of moisture, and then curing in an autoclave.