JPH08175861A - Formed plate of inorganic material and its production - Google Patents

Abstract

PURPOSE: To obtain a formed plate of an inorganic material producible in a mass and having light weight and high strength. CONSTITUTION: This formed plate of inorganic material consists of the top and the reverse surface layers having a dense structure and composed of a cured product of a mixture consisting of 30-60wt.% of cement, 30-60wt.% of a silica-containing substance, 0-15wt.% of perlite and 5-25wt.% of flake and/or wood flour and a porous core layer composed of a cured product of a mixture consisting of 30-60wt.% of cement, 30-60wt.% of a silica-containing substance, 0-15wt.% of perlite, 5-25wt.% of woody fiber bundle and 4-10wt.% of flake.

Description

Detailed Description of the Invention

[0001]

The present invention has a porous structure inside,
The present invention relates to an inorganic molded plate that is lightweight and has excellent insulation properties, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, cement is mixed with reinforcing materials such as wood chips and pulp fibers, and a raw material mixture is further formed by mixing expandable plastic beads and the mixture is heated to foam the expandable plastic beads in the raw material mixture. In addition, by melting the plastic beads foam particles obtained by foaming the expandable plastic beads to form a large number of pores in the molded body, it is lightweight and has insulation properties such as heat insulating properties and soundproofing properties. A method for producing a porous cement board is provided (Japanese Patent Application Laid-Open No. 54-15).
7125, Japanese Patent Publication No. 63-1276).

[0003]

However, in the above-mentioned conventional porous cement board, since the surface has pores, it is not possible to obtain a board material having a smooth surface and excellent cosmetic properties, and also having water permeability and moisture permeability. It will be big. Further, in the case of a conventional wood chip cement board using wood chips as a reinforcing material, there is almost no entanglement of wood chips, so the strength of the product obtained is sufficient unless the pressing force is increased during molding to increase the product density. However, in the case of a conventional pulp-mixed cement board using pulp fibers as a reinforcing material, the density of the cement-pulp fiber mixture is increased, and foaming of the expandable plastic beads is suppressed.

[0004]

As a means for solving the above-mentioned conventional problems, the present invention provides 30 to 60% by weight of cement, 30 to 60% by weight of silicic acid-containing substance, 0 to pearlite.
Front and back layers composed of a cured product of a mixture of 15% by weight, flakes and / or 5 to 25% by weight of wood flour, and cement 30 to
60% by weight, 30 to 60% by weight of silicic acid-containing substance, 0 to 15% by weight of perlite, 5 to 25% by weight of wood fiber bundle, and 4 to 10% by weight of flakes. The present invention further provides an inorganic molded plate, and more preferably, the wood fiber bundle is made bulky by branching and / or bending and / or bending. A desirable production method as the production method of the above-mentioned inorganic molded plate of the present invention is a dry production method with high production efficiency, which is 30 to 60% by weight of cement,
Silicic acid-containing substance 30 to 60% by weight, perlite 0 to 15
% By weight, flakes and / or wood flour 5-25% by weight,
And a mixture A of 30 to 45% by weight of water are spread on a template in a mat form, and further 30 to 60% by weight of cement, 30 to 60% by weight of a silicic acid-containing substance, 0 to 15% by weight of perlite, and a wood fiber bundle. 5 to 25% by weight of flakes, 4 to 10% by weight of flakes, 0.5 to 5% by weight of expandable thermoplastic beads, and 30 to 45% by weight of water, are sprayed on the mixture B in the form of a mat. Step 1 of spraying the mixture A in a mat shape from above to form a mat having a three-layer structure Step 1 Pre-curing by pressing the mat having the three-layer structure 2 Foaming by curing the pre-cured material by heating in an autoclave Is a method for manufacturing an inorganic molded plate, which comprises steps 1, 2, and 3 of foaming thermoplastic resin beads and advancing curing. The present invention will be described in detail below.

[Front and Back Layers] The front and back layers of the inorganic molded plate of the present invention include 30 to 60% by weight of cement and 30 to 6 of silicic acid-containing substance.
It is a cured product of Mixture A with 0% by weight, 0 to 15% by weight perlite, 5 to 25% by weight of flakes and / or wood flour. The above-mentioned cement includes Portland cement, blast furnace cement, silica cement, fly ash cement, various cements such as alumina cement, and the silicic acid-containing substance is, for example, silica sand, silica sand, silica fume, blast furnace slag, It includes various inorganic powders containing silicic acid, such as fly ash, shirasu balloon, perlite, and powder of wood cement board waste material containing silicic acid substances. The cement and the silicic acid-containing substance react by the calcium silicate reaction and harden. In order to smooth the curing by such calcium silicate reaction, the mixture A constituting the front and back layers of the inorganic molded plate of the present invention
Medium cement 30-60% by weight, silicic acid-containing substance 30-6
It is necessary to contain 0% by weight. Perlite is a desirable but not essential component of the present invention because it reduces the weight of the inorganic molded sheet produced and improves dimensional stability. However, when the content of pearlite is 15% by weight or more in the mixture, the strength of the obtained inorganic molded plate decreases and the front and back surfaces become rough. Flake and / or wood powder is used as a reinforcing material for the front and back layers, and it is desirable that the flake has a mesh size of 10 mm and an average mesh size of 4.5 mm and a thickness of 1 mm or less. , Preferably 10-30
A material having a mesh particle size is used. Although flakes have a stronger reinforcing effect than wood flour, the denseness of the front and back layers obtained with flakes only slightly decreases, whereas the strength of the front and back layers obtained with wood flour only slightly decreases. Therefore, it is preferable to use the flakes and the wood flour together, and in that case, the mixing weight ratio of the flakes and the wood flour is 80:20 to 20:80.
The degree. However, the use of flakes or wood flour alone achieves the object of the present invention. Flakes and /
If the amount of wood powder in the mixture A is 5% by weight or less, the strength of the front and back layers becomes insufficient, and if it is 25% by weight or more, the flame retardancy decreases. Further, the front and back layers may be mixed with about 5 to 20% by weight of powder of a waste wood cement board comprising cement and a wood reinforcing material. The wood cement board waste powder is usually a fine powder of 16 mesh or less, and the powder is filled in the voids existing in the cement matrix to reinforce the cement matrix and improve the moisture absorption and water absorption of the product. The mixture A constituting the front and back layers of the inorganic molded plate of the present invention further contains magnesium chloride, magnesium sulfate, calcium chloride,
A hardening accelerator such as calcium sulfate, sodium aluminate, potassium aluminate, aluminum sulfate, and water glass may be added.

[Core Layer] The core layer of the inorganic molded plate of the present invention comprises 30 to 60% by weight of cement, 30 to 60% by weight of silicic acid-containing substance, 0 to 15% by weight of perlite, and 5 to 25 of wood fiber bundles.
It is made of a cured product of the mixture B containing 4% to 10% by weight of flakes and is porous. The above cement, silicic acid-containing substance,
The same pearlite as the front and back layers is used in the same ratio. The wood fiber bundle is used as a reinforcing material for the core layer, and preferably has a diameter of about 0.1 to 2.0 mm, a length of about 2 to 35 mm, and more preferably 10 to 30 mm. The desirable shape of the wood fiber bundle is that which is made bulky by branching and / or bending and / or bending. In order to produce a wood fiber bundle which is made bulky by branching and / or bending and / or bending, the wood is immersed in a chemical solution such as sodium hydroxide, sodium sulfite, calcium sulfite, or the wood is Without completely dissolving the lignin, hemicellulose, resin, etc. that play the role of the binder of the wood monofilament contained in the wood by heating with steam, or by using the chemical solution immersion and steam heating together It is swelled only after it is swelled and then the above binder is left to be defibrated, and has a larger diameter than pulp fibers defibrated by removing lignin almost completely from the binder. If the wood fiber bundle is branched, the diameter of the wood fiber bundle is in the range of about 0.1 to 2.0 mm, assuming that the wood fiber bundle is not branched, and the wood fiber bundle is bent and / or folded. When bent, the actual length of the wood fiber bundle is preferably in the range of 10 to 30 mm, not the distance between the ends. The wood fiber bundle is bulky due to the above size and shape, but its bulk specific gravity is about 0.03 to 0.0.
It is in the range of 5 g / cm ³ . Here, the volume specific gravity is 8 cm in inner diameter and the volume of 2000 ml is filled with 2000 ml of the absolutely dried wood fiber bundle, and the whole weight is measured, and the weight of the whole graduated cylinder is subtracted from the total weight to obtain the wood fiber bundle. Of the graduated cylinder is placed on the wood fiber bundle filled with a disk that fits exactly into the inner diameter of the graduated cylinder, a weight is placed on the disk, and a weight of 1 kg is applied to the wood fiber bundle. It is determined by measuring the volume of the wood fiber bundle and dividing the weight (g) of the wood fiber bundle by the volume (cm ³ ). In order to make the wood fiber bundle bulky by branching and / or bending and / or bending, the degree of swelling and defibration of the binder is adjusted. The defibration is performed by, for example, a gliding disc, and the degree of defibration is adjusted by adjusting the disc gap of the gliding disc. In the mixture B, the wood fiber bundles that have been made bulky by branching and / or bending and / or bending are entangled with each other over a certain distance, but the fiber bundles become pulp fibers. In comparison, since the diameter is large, it has some rigidity and is unlikely to be entangled in a thread-like shape. However, if the actual length of the wood fiber bundle becomes longer, the tendency to be entangled in a thread-like shape becomes greater even if it is 30 mm or less. Therefore, in the present invention, the addition of flakes prevents the entanglement of the wood fiber bundle in the form of a string without reducing the strength of the product. That is, when flakes are added, the flakes enter the inside of the spiral wood fiber bundle and prevent the wood fiber bundle from being transformed from a spiral shape into a string shape. As the flakes, the same flakes as those used for the front and back layers are used. As described above, the flakes are added to the core layer in the range of 4 to 10% by weight, but if the amount is less than 4% by weight, the effect of preventing the string-like entanglement of the wood fiber bundles is not remarkable and 10% by weight is added. If it exceeds, the strength of the product is adversely affected. In this manner, the cement and the silicic acid-containing substance are held between the intertwined fiber bundles in the presence of the flakes. The above-mentioned flakes, in combination with the rigidity of the fiber bundles, serve to maintain the distance between such fiber bundles and thus to maintain bulkiness. Therefore, when the dry production method is applied to the production of the inorganic molded plate of the present invention, the mixture of the curable inorganic powder, the wood fiber bundle and the flakes can be sufficiently loosened by mechanical stirring or the like, and the mixture can be molded into a mold. It is extremely easy to evenly spread on the plate, and after spraying, the curable inorganic powder is entangled by the entanglement of the wood fiber bundles in the presence of flakes over a certain distance as described above. It is possible to form a mat that does not lose its shape. In the product, the wood fiber bundles in the matrix have a small specific gravity due to the specific reinforcing effect that the fiber bundles are strongly entangled with each other over a certain distance in the presence of flakes as described above. It provides a core layer with high strength. In the present invention, in order to make the core layer porous, a method is generally applied in which the thermoplastic foam particles are mixed with the mixture to be hardened and the thermoplastic foam particles are heated to be softened and shrunk. In order to mix the thermoplastic foam particles in the mixture B, the expandable thermoplastic beads are mixed in addition to the thermoplastic foam particles which have already been expanded, and the mixture B is mixed before or during curing. The expandable thermoplastic beads may be expanded to form thermoplastic foam particles. In this case, when a wood fiber bundle that is made bulky by branching and / or bending and / or bending is used as the wood fiber bundle, the structure of the mixture B becomes sparse, so that foaming of the expandable thermoplastic beads does not occur. There is an advantage that it is performed uniformly and smoothly. The expandable thermoplastic beads used in the present invention are beads of thermoplastic such as polyethylene, polypropylene and polystyrene impregnated with a volatile foaming agent such as propane, butane, pentane and petroleum ether. The amount of the thermoplastic foam particles or the expandable thermoplastic beads to be added is usually 0.5 to 5% by weight in the mixture B. When the addition amount of the thermoplastic plastic foam particles or the expandable thermoplastic plastic beads is 0.5% by weight or less, the ratio of pores in the core layer is reduced and the insulation property becomes insufficient. When the content is more than 5% by weight, the proportion of the organic matter in the inorganic molded plate of the present invention becomes excessive and the flame retardancy of the inorganic molded plate of the present invention decreases. Further, like the front and back layers, 5 to 20% by weight of wood cement board waste material powder may be added to the core layer.

[Manufacturing Method] As a method for manufacturing the inorganic molded plate of the present invention, it is desirable to adopt a dry manufacturing method in which the steps are easily continuous and the apparatus is simple. In step 1 of the dry manufacturing method, the mixture A is sprinkled on the template in a mat shape, and then the mixture B is sprinkled on the mat in a mat shape,
Further, the above-mentioned mixture A is sprayed on it in the form of a mat. At this time, 30 to 45% by weight of water is added to each of the mixture A and the mixture B for the curing reaction. Mixture B
When flakes are added to the mixture and the wood fiber bundles are made bulky by branching and / or bending and / or bending as described above, the mixture B becomes easy to loosen, and the mixture B is evenly dispersed on the template. It will be easier. In the continuous manufacturing method, a large number of the templates are placed on the belt conveyor. The raw material mixture sprinkled on the template is slightly pressed by a roll or the like if desired, and the mat is then pre-cured in the presence of water in step 2 to be formed into a desired shape. Clamping conditions are normally 10 to 20 kgf.
/ Cm ² , the temperature is 60 to 80 ° C., the time is about 20 to 30 hours, and the heating is usually performed by 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 pre-cured product obtained by the compression pre-curing in the above step 2 is cured in an autoclave in step 3. The curing conditions are usually a pressure of 10 to 20 kgf / cm ² , a temperature of 160 to 180 ° C., and a time of 5 to 10 hours. The calcium silicate reaction between the cement and the silicic acid-containing substance is completely carried out by the autoclave curing, and when expandable thermoplastic beads are added to the core layer, the expandable thermoplastic beads are completely expanded. ,
At the same time, the plastic foam particles formed by the foaming of the expandable thermoplastic beads are melted and the foaming agent in the cells escapes to the outside, the plastic foam shrinks rapidly, and a large number of voids are formed inside the core layer. A hole is formed. Then, a plastic coating layer derived from the thermoplastic foam particles is formed on the inner wall surface of the pores. In this way, the inorganic molded plate of the present invention is produced, and the thickness of the front and back layers of the inorganic molded plate of the present invention is usually 10 of the total thickness.
-30%, and the density is usually 0.9-1.1 g / cm ³ .

[0008]

In the present invention, both the front and back layers and the core layer contain 30 to 60% by weight of cement and 30 to 60% by weight of the silicic acid-containing substance, so that the hardening of each layer based on the calcium silicate reaction proceeds smoothly. Further, when the dry manufacturing method is adopted, the calcium silicate reaction proceeds almost completely due to autoclave curing and hardens in the final dimensional state of the molded body, so the molded body once cured is less affected by the external environment. The dimensional stability of the product is improved. Further, since the front and back layers contain 5 to 25% by weight of flakes and / or wood powder, the front and back layers are highly dense and rich in surface smoothness. Furthermore, since the core layer contains 5 to 25% by weight of wood fiber bundles and 4 to 10% by weight of flakes and is porous, the core layer is lightweight and has excellent sound insulation and heat insulating properties. The front and back layers and the core layer contain 25% by weight or less of the wood reinforcing material such as flakes, wood powder, and wood fiber bundles, so that the inorganic molded plate of the present invention is flame-retardant. In addition, since the flakes are present in the core layer in the range of 4 to 10% by weight, the entanglement of the wood fiber bundles in the form of a string is prevented, and when the inorganic molded plate of the present invention is manufactured by the dry manufacturing method, the raw material mixture is molded. It can be sprayed evenly on the board. If the wood fiber bundle used for the core layer is made bulky by branching and / or bending and / or bending, the bulk specific gravity of the core layer will be reduced but the strength will not decrease, and foaming will also occur. The foaming of the hydrophilic thermoplastic beads is also carried out uniformly and smoothly. The front and back surfaces of the inorganic molded plate of the present invention may be embossed, but in that case, a very sharp and deep emboss is applied to the dense front and back layers and the core layer which is porous and therefore has cushioning properties. Can be done.

[0009]

【Example】

 [Examples 1 to 10] (1) Table 1 shows the formulation of the mixture A (for front and back layers).

[Table 1] * 1: Uses an average mesh of 4.5 mm and an average thickness of 0.6 mm. * 2: Use an average particle size of 20 mesh. * 3: Weight% based on cement. (2) The formulation of the mixture B (for core layer) is shown in Table 2.

[Table 2] * 1: Uses the same mixture A. * 2: Branched and / or curved and / or bent pieces with an average particle size of 1.0 mm and a length of 20 mm are used. * 3: Weight% based on cement. (3) To each of the mixture A, 30% by weight of water based on the solid content, and to each of the mixture B, 35% by weight of water based on the solid content, were added, and the mixture A was sprayed onto the lower template. 8mm thick mat, and sprinkle mixture B on it, 50mm
Make a thick mat and sprinkle mixture A on it
A mat having a thickness of mm is formed, and an upper mold plate is brought into contact with the mat from above, and after press molding, pressure hardening is performed at a pressure of 10 kgf / cm ² and a temperature of 70 ° C. for 25 hours. The obtained laminated molded body was a plate-like body having a thickness of 18 mm, and the laminated molded body was then aged in an autoclave at a pressure of 15 kgf / cm ² and a temperature of 165 ° C. for 7 hours to obtain the cement in the laminated molded body. And the silicic acid-containing material are hardened by a calcium silicate reaction, and the expandable polystyrene beads in the core layer are foamed and then softened and shrunk.
In this way, the mixture 1B, 2B, 3B, 4B, 5B is combined with each of the mixture 1A, 2A and Examples 1 to 1 are combined.
0 inorganic molded plate samples were obtained.

Comparative Examples 1 and 2 (1) As the mixture A, 1A and 2A shown in Table 1 of the examples are used. (2) As the mixture B ′, the one having the formulation shown in Table 3 is used.

[Table 3] * 1: Use the same one used in the example. * 2: Weight% relative to cement. (3) Add water to each of the mixture A and the mixture B'as in the example, and then Similarly, the inorganic plate samples of Comparative Examples 1 to 4 were prepared by the dry manufacturing method.
At this time, since the mixture B ′ of the formulations 1B ′ and 2B ′ had a string-like entanglement of the wood fiber bundles, when the mixture B ′ was sprayed on the mat of the mixture A formed on the lower template,
Some non-uniformity occurred.

[Evaluation of Physical Properties] Table 4 and Table 4 show the results of measuring and evaluating the apparent specific gravity, bending strength, freeze-thaw resistance (freezing resistance), and surface condition of the samples of Examples 1 to 10 and Comparative Examples 1 to 4 above. 5 shows.

[0012]

[Table 4]

[0013]

[Table 5] The physical property test conditions were the same as in Examples 1-10.

With reference to Tables 4 and 5, all the samples of the examples are lightweight and have high strength, and the surface condition is good. Even in No. 10, freeze resistance was maintained and the surface was extremely dense and smooth. However, in the samples of Comparative Examples 1 to 4 using the mixture B ′ to which flakes were not added, it was difficult to uniformly disperse the mixture B ′, and therefore the strength and the surface condition were inferior to those of the examples.

[0015]

Therefore, according to the present invention, an inorganic molded plate which is lightweight and has high strength, and whose surface state is dense and smooth can be obtained, and the inorganic molded plate can be easily mass-produced by a dry manufacturing method. Can be done.

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Claims (3)

[Claims] 1. Front and back layers comprising a cured product of a mixture of 30 to 60% by weight of cement, 30 to 60% by weight of silicic acid-containing substance, 0 to 15% by weight of perlite, 5 to 25% by weight of flakes and / or wood flour. , 30 to 60% by weight of cement, 30 to 60% by weight of silicic acid-containing substance, 0 to 15% by weight of perlite, 5 to 25% by weight of wood fiber bundle, and 4 to 10% by weight of flakes. An inorganic molded plate characterized by comprising a core layer 2. The inorganic molded plate according to claim 1, wherein the wood fiber bundle is made bulky by branching and / or bending and / or bending. 3. Cement 30-60% by weight, silicic acid-containing substance 30-60% by weight, perlite 0-15% by weight, flakes and / or wood flour 5-25% by weight, and water 30.
~ 45 wt% of mixture A is spread on the template in the form of a mat, and further 30-60 wt% of cement and silicic acid-containing substance 3
0-60% by weight, perlite 0-15% by weight, wood fiber bundles 5-25% by weight, flakes 4-10% by weight, expandable thermoplastic beads 0.5-5% by weight, and water 30-45% by weight. And a mixture B is sprayed on the mat in the form of a mat, and the mixture A is further sprinkled on the mat in the form of a mat to form a mat having a three-layer structure. Step 2 for curing Step 3 for curing the pre-cured product by heating and curing the pre-cured autoclave to promote foaming of the expandable thermoplastic beads, and a method for producing an inorganic molded plate comprising steps 1 and 2 above