JP2910901B2 - High-strength plate and bearing wall using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-strength plate which can be used as a surface material for a load-bearing wall in place of plywood or the like, and a load-bearing wall using the same.

[0002]

2. Description of the Related Art Conventionally, there are various types of structural members constituting a load-bearing wall of a wooden house, but the simplest one is a plywood on the front and back surfaces of a wooden frame. Alternatively, plywood and gypsum board are attached.

[0003] However, the wood constituting the plywood is difficult to obtain from the viewpoint of environmental protection and tends to be expensive. Further, plywood has a low surface hardness and is not only easily deformed such as dents due to bruising or the like, but also has a poor surface smoothness, so that a cloth cannot be directly applied. Further, a plywood made of wood has a large hygroscopic property and a large expansion rate in a thickness direction, so that a step is easily generated. Moreover, the plywood has a problem that it is easily attacked by termites and rot fungi.

For this reason, it has been considered to use particle board, MDF (medium specific gravity fiber board) or the like as a plate-like body in place of plywood. Since the coefficient of expansion is large, the center of the frame may swell, and is not necessarily suitable as a wall base.

[0005] In view of the above problems, an object of the present invention is to provide a high-strength plate-like body replacing a plywood for a load-bearing wall, and a load-bearing wall using the same.

[0006]

According to the present invention, there is provided a plate-shaped body comprising 30 to 70% by weight of mineral fibers, 15 to 25% by weight of organic fibers, and 25 to 35% by weight of a binder to achieve the above object. A mixture comprising 50 to 70% by weight of an inorganic foam, 5 to 15% by weight of an organic fiber, and 25 to 35% by weight of a binder is provided between upper and lower layers of a wet mat obtained by wet-making a slurry having a component composition. An intermediate layer portion is formed and heated and pressed to have an overall specific gravity of 0.60 to 0.80.

[0007] The mineral fibers forming the upper and lower layers are added to obtain a desired bending strength and to suppress a thickness expansion coefficient and a moisture expansion coefficient upon water absorption.
Examples thereof include rock wool, slag wool, mineral wool, and glass fiber, and these can be used alone or in combination of two or more. The composition ratio of the mineral fibers in the upper and lower layers is preferably 30 to 70% by weight. If the content is less than 30% by weight, the bending strength is low, and the surface is easily broken at the time of screw driving.
If it exceeds 70% by weight, drainage during papermaking deteriorates, and a good wet mat cannot be obtained. Further, the amounts of organic fibers and binders to be described later are relatively low, and surface hardness and screwing performance are reduced. Because it cannot be high.

The organic fibers forming the upper and lower layers are added in order to improve the bending strength, and natural fibers and synthetic fibers having a high single fiber strength and a small decrease in the strength when wet are preferable. . Examples of natural fibers include leaf fibers such as sisal, manila, and New Zealand hemp in addition to bast fibers such as flax, cannabis, and jute, and examples of synthetic fibers include polyester, nylon, and acrylic fibers. Yes, these alone or
Two or more can be used in combination. In particular, since synthetic fibers are expensive, it is preferable to use them together with natural fibers. Natural fibers and synthetic fibers may be recycled products used for fabrics and the like. The composition ratio of the organic fibers in the upper and lower layers is preferably 15 to 25% by weight. If the amount is less than 15% by weight, the proportion of mineral fibers relatively increases, but the mineral fibers are brittle and the strength does not increase. If it exceeds 25% by weight, the moisture content of the wet mat is reduced. This is because it becomes high and it becomes easy to puncture at the time of heat and pressure.

The binder forming the upper and lower layers is for linking and integrating the mineral fibers and the organic fibers. For example, synthetic resins such as polyvinyl alcohol resin, phenol resin and acrylic resin, starch and the like are used. These can be used alone or in combination of two or more. However, a small amount of starch can increase the bending strength, but since it alone reduces the adhesive strength when wet, it is preferable to use a phenol resin, an acrylic resin, or the like in combination.

The inorganic foam forming the middle layer is for reducing the weight while maintaining the compressive strength, and includes, for example, pearlite, shirasu foam, silica flower, glass foam and the like. Alternatively, two or more kinds can be used in combination. The composition ratio of the inorganic foam in the middle layer is preferably set to 50 to 70% by weight. 5
When the content is less than 0% by weight, the ratio of the organic fibers and the binder added to form the middle layer relatively increases.
Although the strength is improved, the holding power of the nail is reduced and the effect of lowering the specific gravity is not obtained. When the weight exceeds 70% by weight, the ratio of the organic fiber or the binder is reduced, and the overall strength is improved. This is because it becomes difficult.

The organic fibers forming the middle layer are added to connect the inorganic foams to each other to improve the strength. As the organic fibers forming the middle layer, the upper and lower layers are formed. In addition to the organic fibers, for example, pulp and heat-fused fibers may be used. The composition ratio of the organic fibers in the middle layer is preferably 5 to 15% by weight. 5% by weight
If the addition amount is less than the above, the inorganic foam is mainly connected only by the binder, so that it is brittle and easily broken, and if it exceeds 15% by weight, the dimensional change becomes large.

The binder for forming the middle layer portion is added to connect the inorganic foam and the organic fiber, and the material and amount of the binder are the same as those for forming the above-mentioned upper and lower layer portions. Therefore, although the description is omitted, it is not always necessary to add the same material in the same amount, and a different material can be used in an appropriate amount. Use of heat-fusible fibers as a binder is also highly effective.

Next, a method for manufacturing a high-strength plate-like body will be described. For example, mineral fibers, organic fibers and a binder are suspended in water to obtain an aqueous slurry, which is wet-processed to obtain a wet inorganic mat to be a lower layer and an upper layer.

On the other hand, the inorganic foam, the organic fibers and the binder are mixed, for example, under spraying of water at a ratio of 100 to a solid content of 100 to obtain a middle layer mixture. Then, the mixture is wet-processed to form a middle layer by uniformly spraying and depositing the mixture on the surface of the wet inorganic mat which will be the lower layer obtained by wet-making, and the wet inorganic mat which will be the upper layer will be laminated thereon. To obtain a laminate.

Next, when the laminate is heated and pressed by a press, the air in the middle layer is extruded to reach a certain density, and then the density in the upper and lower layers increases. Further, when heated and pressed, a part of the inorganic foam in the middle layer bites into the upper and lower layers, and the thin portion of the inorganic foam is destroyed to increase the density of the middle layer, and at the same time, the specific gravity of the upper and lower layers increases. Increase. Heating and pressing are performed until the overall specific gravity becomes 0.60 to 0.80. When the overall specific gravity is less than 0.60, the wood screw holding force and the like decrease, and when it exceeds 0.80, it becomes heavy,
In addition, the workability of cutting, transporting, and the like is reduced because of the hardness.

[0016] From the viewpoint of productivity, it is not advisable to complete the drying by a continuous press, but it is more preferable to separately dry the product by a dryer after integration. Further, in the above-described production method, a production method combining a dry method and a wet method has been described. However, all of the production methods may be performed by a wet method, and an arbitrary papermaking method can be selected.

[0017]

Next, an embodiment according to the present invention will be described. (Example) Rock wool 50% by weight as mineral fiber,
20% by weight of recycled jute as organic fiber, 20% by weight of powdered phenol as binder and 10% by weight of starch are put into clear water and stirred to obtain an aqueous slurry having a concentration of 2%. To obtain a wet inorganic mat to be a lower layer portion and an upper layer portion having a thickness of 5 mm.

On the other hand, 65% by weight of pearlite as an inorganic foam, 5% by weight of pulp and 5% by weight of heat-fusible fibers as organic fibers, 15% by weight of an acrylic resin and 10% by weight of starch as a binder were added to these solid components. The mixture was mixed with water at a ratio of 30 to obtain a mixture for the middle layer.

Then, the mixture for the middle layer is uniformly spread and deposited on the wet inorganic mat to be the lower layer so as to have a thickness of 25 mm, and the wet inorganic mat to be the upper layer is disposed thereon. A laminate having a thickness of 35 mm was obtained. Then, the laminate was pressed by a continuous press at a temperature of 200 ° C. and a pressure of 10 kg / cm ² to form a 9 mm-thick plate-like body.
The sample was dried in a drying oven at a temperature of 15 ° C. for 15 minutes, cut into appropriate lengths, and used as samples. The overall specific gravity of the obtained sample was 0.69.

Comparative Example A commercially available plywood (Type I plywood having a thickness of 9 mm) was used as a sample.

Next, the measurement results of the physical properties of the examples and comparative examples are shown in Table 1.

[Table 1]

The above measurement results were obtained based on the following method. Flexural strength: based on JIS A 5907-1977. Bending Young's modulus: Based on JIS Z 2113-63. JAS1 flexural strength: After wetting and drying according to the wet method for JAS special plywood, the flexural strength was measured according to JIS A 5907. Residual strength: (Bending strength at JAS1 water resistance / Bending strength under normal conditions) × 100 Peeling strength: According to JIS A 5908. Wood screw holding power: Based on JIS A 5908. Water absorption: {(weight after immersion for 24 hours-weight before immersion)
/ Weight before immersion} × 100 Expansion rate of water absorption thickness: According to JIS A 5908. Hygroscopic linear expansion coefficient: It was performed in accordance with JIS A 5403.

As is clear from the above measurement results, when the example and the comparative example (plywood) are compared, the density, bending strength, bending Young's modulus, wood screw holding power, and coefficient of linear expansion of moisture absorption of the example are compared. Although it is slightly inferior to the comparative example, this is a difference that is not a problem in practical use. In addition, it was found that the example had better performance than the comparative example in the JAS1 bending strength showing the characteristics at the time of water absorption. Furthermore, the peel strength and the compressive strength of the embodiment are at least twice as large as those of the comparative example. In particular, since the embodiment is almost four times as large as the comparative example in the Brinell hardness, the occurrence of scratches and dents due to transportation is reduced. I understand. Further, the water absorption rate of the example is smaller than that of the comparative example. In particular, the water absorption thickness expansion coefficient of the example is one third or less of the comparative example. For this reason, it turned out that generation | occurrence | production of the level | step difference by water absorption and moisture absorption can be eliminated. Moreover, when the surface shapes of the examples and comparative examples were visually observed, it was found that the examples were smoother than the comparative examples, and that the cloth could be directly adhered to the surfaces of the examples.

As is evident from the above results, it was found that the high-strength plate according to the example can provide a substitute having better water resistance, moisture resistance and surface performance than plywood.

Next, a frame having a width of 910 mm and a height of 2400 mm is formed by using a square member having a cross section of 38 mm × 89 mm.
When the plate-like body according to the above-described embodiment was attached to one surface of the frame with a nail and tested according to JIS A1414, a load-bearing wall having a wall magnification of 3 was obtained. Has a wall magnification of 5 for the first floor of a 3rd floor wooden house
It was found that a load-bearing wall could be obtained.

[0026]

As is apparent from the above description, according to the high-strength plate of the first to fourth aspects of the present invention, it is easier to obtain the raw material than the plywood, which causes environmental destruction. Without increasing the price. Furthermore, according to claim 5 of the present invention, since a load-bearing wall in which the high-strength plate-like body having the above-described performance is adhered to both surfaces of the frame body is obtained, the performance is equal to or higher than that of the load-bearing wall in which plywood is adhered. Is obtained. Further, since the high-strength plate-like body according to the present invention has a high surface hardness, if it is applied to a load-bearing wall, it will be less likely to be damaged during transportation, which is convenient for transportation. further,
Since it is heated and pressed, a load-bearing wall having a smooth surface and capable of directly attaching a cloth can be obtained. And since it has less water absorption and hygroscopicity than wood and a small expansion coefficient in the thickness direction, a bearing wall in which a step is unlikely to be formed can be obtained. Moreover, since it is covered with upper and lower layers mainly composed of mineral fibers,
A bearing wall resistant to attack by termites and rot fungi is obtained. Therefore, there is an effect that a bearing wall excellent in water resistance, moisture resistance and surface performance can be obtained.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-50417 (JP, A) JP-A-59-88382 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) E04C 2/12 E04C 2/24 E04C 2/20 B32B 1/00-35/00

Claims (5)

(57) [Claims] 1. Between upper and lower layers comprising a wet mat obtained by wet-making a slurry having a composition of 30 to 70% by weight of mineral fibers, 15 to 25% by weight of organic fibers and 25 to 35% by weight of a binder. A middle layer is formed from a mixture of 50 to 70% by weight of an inorganic foam, 5 to 15% by weight of an organic fiber, and 25 to 35% by weight of a binder.
A high-strength plate-shaped member characterized by being 0.80. 2. The high-strength plate-like body according to claim 1, wherein the organic fibers added to the upper and lower layers are bast fibers, leaf fibers, and other vegetable fibers. 3. The high-strength plate according to claim 1, wherein the organic fibers added to the upper and lower layers are nylon, polyester, and other synthetic fibers. 4. The organic fiber added to the middle layer portion comprises pulp and heat fusible fiber.
4. The high-strength plate-shaped member according to any one of items 3 to 3. 5. A slurry having a composition of 30 to 70% by weight of mineral fibers, 15 to 25% by weight of organic fibers, and 25 to 35% by weight of a binder is obtained on at least one side of a wooden frame by wet papermaking. 50 to 70% by weight of inorganic foam, 5 to 15% by weight of organic fiber, binder 2
A bearing wall comprising a high strength plate-like body having a thickness of 9 mm or more and an overall specific gravity of 0.60 to 0.80, on which an intermediate layer is formed of a mixture of 5 to 35% by weight, is adhered.