JPH07178708A - Structure of wooden core material board - Google Patents

Abstract

PURPOSE:To obtain a structure or a wooden core material board with good strength and dimensional stability, water resistance and fire resistance and further modified so as to be suitable for various materials. CONSTITUTION:Improvement is provided to a board by bonding a surface material prepd. by impregnating a woven fabric or a non-woven fabric with a thermosetting resin on both faces of a wooden core material board such as a particle board, a wafer board and a wooden fiber board. 11, 12 and 13 are respectively a base material of the wooden core material board, a glass fiber-woven fabric and a moisture-proof layer. When this wooden core material board is used e.g. as a building board, it is durable to ultra-loading and even when it is under an atmosphere for moisture, the amt. of warpage is remarkably less than that of the conventional board and it is especially optimum board as a laid bed on a concrete face.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a wood-based core material board, more specifically, strength and dimensional stability,
The present invention relates to the structure of a wood-based core material board modified to be suitable for various materials such as water resistance and fire resistance.

[0002]

2. Description of the Related Art In recent years, major producers of South Sea timber have tightened timber cutting regulations because they would stop the destruction of tropical rain forests, resulting in unstable prices and supply of plywood. There is a growing need to substitute such materials as particle boards, particle boards, and wood fiber boards. However, since such wood-based core material boards are inferior in various properties such as strength, dimensional stability, and water resistance to plywood and the like, the use range of the board is limited. Was there. Hereinafter, the example used as a building member will be described in more detail. For example, in recent years, these wood-based core material boards have been used for a floor laid on a floor slab such as a gymnasium. However, when holding various events in the gymnasium, extra heavy objects may be placed on the floor. It is natural that a floor with sufficient strength and rigidity for such a load is required.

Considering the case where this wood-based core material board is bent under a load, as shown in FIG. 13, this board 1 has a compression side 1a, a tension side 1b, and the expansion and contraction of this boundary. Although it can be considered separately as the neutral surface 1c, the strength of the wood-based core material board 1 is generally weaker in tensile strength than in compressive strength. Is the standard of strength for the board. In this way, it is undeniable that the use range of the wood-based core material board as it is is limited, and the strength, dimensional stability, etc., which are the drawbacks of such a board, are various properties. Was required to be added to this.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the drawbacks of the conventional wood-based core material board, and has various properties modified in addition to strength and dimensional stability. Is intended to provide.

[0005]

The present invention has the following constitution in order to achieve the above object. That is, by applying a woven or non-woven fabric impregnated with a thermosetting resin or a surface material made of a synthetic resin layer on both sides of a wooden core board, the board is modified. The structure of the wood-based core material board is characterized in that it is particularly adopted as a board for construction, at least one side of the wood-based core material board surface. A tensile strength-reinforcing material is disposed on the surface or inside thereof, and a moisture-proof layer is provided as a surface material on both sides of the wood-based core board.

[0006]

The wood-based core material board used here is a particle board, oriented wafer board, wafer board, wood-based fiber board (hard board, MDF). ,
Insulation board), wood wool cement board, wood chip cement board and the like. The surface material is selected variously depending on the purpose of its modification, but is usually a woven cloth, a non-woven cloth, a synthetic resin layer having various properties, or the like.
The nonwoven fabric is a layer impregnated with a thermosetting resin. The woven or non-woven fabric (layer) is not particularly limited, but is an inorganic fiber such as glass fiber, carbon fiber, inorganic whisker, rock fiber, rock wool, metal fiber, metal such as amorphous metal fiber, or the like. A fiber can be illustrated.

On the other hand, as the thermosetting resin to be impregnated into the woven or non-woven fabric, a resin having a characteristic required as a surface material is selected, for example, a phenol obtained by a reaction of phenols and aldehydes. Resin, an epoxy resin obtained by adding a curing agent to an oligomer having a reactive epoxy group at the terminal, a thermosetting ethylene vinyl acetate copolymer,
Unsaturated polyester resin, urea resin, melamine resin,
Examples thereof include urethane resins, and various fillers such as lead stearate, dibutyltin laurate, and the like.
Carbon black, calcium carbonate, titanium white,
Mica, glass sphere, aluminum hydroxide, antimony oxide, tri (2,3 dibromopropyl) phosphate, aliphatic sulfonate, higher alcohol sulfate ester, etc.
A heat stabilizer, a reinforcing agent, a coloring agent, a flame retardant, an antistatic agent, etc. are blended and used.

Among these resins, resins having self-adhesiveness with the wood-based core material, such as epoxy resin and urethane resin, are used as they are when the resin having poor self-adhesiveness with the core material is used. Via a suitable adhesive between the two,
It is heat-pressed to form an integral wood-based core board. Synthetic resin as the surface material is a film such as polyethylene, vinyl chloride, vinylidene chloride, Teflon, nylon, etc. as it is, and in some cases, various paints can be adopted. Especially, the moisture-proof layer as a construction board will be described later. To do.

Among them, as a material used for construction boards, it is preferable to provide a moisture-proof layer as a surface material on both sides of the wooden core material board, and particularly preferably, the wooden core material board. The tensile strength-reinforcing material is disposed on at least one surface of the inner surface or inside thereof. And, the tensile strength-reinforcing material is larger than the Young's modulus of the wood-based core material board base material,
Structurally speaking, it is preferable that the side surface of the wooden core material board is also provided with a moisture-proof layer. Examples of the tensile strength-reinforcing material include glass fiber woven fabrics, inorganic stuffs such as ceramics and rock wool, and organic woven fabrics such as polyester, acrylic, vinylon and polypropylene, nets and non-woven fabrics.

In the construction board having such a structure,
When used for a floor, the tensile stress side generated in the cross section of the wood-based core material board due to the load applied from above the floor is provided with a tensile strength-reinforcing material capable of withstanding the stress. It will be placed inside or on the surface. By doing so, it is possible to cope with a super load, reduce the amount of dimensional change of the material due to repeated humidification, and have excellent dimensional stability, for example, a construction board suitable for a wooden core material board for a floor. It has become.

In the case of using plywood for example as the tensile strength-reinforcing material, one having a Young's modulus larger than that of the wood-based core material board base material is adopted, and the part of the wood-based core material board base material is used. −
Tickle board alone is about 15000-25000 kg /
cm ² is about 60,000 kg / cm for plywood
^{There are two} .

Among the moisture-proof layers as the surface material, those applied to the surface of the board include resins such as acrylic, urethane, epoxy and phenol, and also various films made of polymer materials. It can be used. Further, examples of the sheet-like material include paper, cloth, resin and the like. It is desirable that this moisture-proof layer is applied not only to the front and back surfaces of the board but also to the side surface (the mouth).

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A wood-based core material board of the present invention will be described below with reference to the drawings. FIG. 1 shows the first wood-based core material board of the present invention.
FIG. 6 is a cross-sectional view of Example A, which is an example of a wood-shaped core material board in which a reinforcing material internally added to a core material board base material and a surface material improve bending strength. In the figure, 11 is a particle board which is a base material of the board A, and a reinforcing net 12 made of vinylon and a non-woven fabric 1 made of the same as the surface material are provided on both sides of the board 11.
3 was contacted with a prepreg sheet holding a phenol resin, and hot pressed for 10 minutes under the conditions of 180 ° C. and 10 kgf / cm ² to obtain a board of the first embodiment A. The net 12 used has a tensile strength of 860 kg.
f / cm, the nonwoven fabric 13 has a density of 36 g / m ² , and these laminated sheets are impregnated with phenol resin at 36 g / m ² .

The bending strength test was conducted according to JIS-A-1408. The bending strength of the particle board itself was about 200 kgf / cm ² , while it was about twice (3).
The effect of ^{20 to} 380 kgf / cm ² ) was obtained. or,
Young's modulus is also the particle board alone (1.5 to 2.5 x
10 ⁴ kgf / cm ² ), the result of the wood-based core material board A of the present invention was 3.9 to 4.5 × 10 ⁴ kgf / cm ² .

In the wood-based core material board A of the present invention, the surface material serves as a moisture-proof layer as it is, and further, it has a flame retardant effect and has the above-mentioned bending strength. It will be a defeat.

FIG. 2 is a cross-sectional view of a second embodiment B of the wood-based core material board of the present invention, in which the amorphous metal fiber non-woven layer is used as the surface material 13 on both surfaces of the core material board base material 11. Pheno
Resin was impregnated, and a wood-based core material board B was obtained in the same manner as described above. This wood-based core material board B is a surface material 13
By attaching the above to both sides thereof, the bending strength and fire resistance were improved, the occurrence of warpage was suppressed, and the electromagnetic shielding property was further provided.

FIG. 3 is a cross-sectional view of a third embodiment C of a wood-based core material board of the present invention, which is an example most suitable for a building board, in which the core material board is used as a base material. In this example, a moisture-proof layer is formed after internally adding a reinforcing material. In the figure, 11 is a particle board which is a base material of the board C, and a glass fiber woven fabric 12 is internally added as a tensile reinforcement material near the surface of the lower surface on the tensile side in the cross section of the board 11. It was made. And this box
A moisture-proof layer 13 made of acrylic resin on the upper and lower surfaces of the window 11.
Is formed by coating. Although not shown, a moisture-proof layer is also applied and formed on the side surface.

FIG. 4 shows a fourth construction board according to the present invention.
8 is a cross-sectional view of Example D, which is an example in which a moisture-proof layer 13 is formed after a reinforcing material 14 is attached to one side of a board substrate 11. That is, the plywood 14 is attached to the lower surface of the particle board 11, that is, the surface on the pulling side, as a tensile-proof reinforcing material. The plywood 14 used here has a Young's modulus that is about three times that of the particle board 11 of the base material. The moisture-proof layer 13 used was the same as in the previous example.

FIG. 5 is a sectional view of a fifth embodiment E of the building board of the present invention, which is an example in which the moisture-proof layer 13 is formed by impregnation. In the figure, the particle board 11 of the base material
The fabric 1 as a reinforcing material near the lower surface of the same as in the first embodiment.
2 is made internal, and then the entire surface of the board 11 is impregnated with paraffin to form the moisture-proof layer 13.

FIG. 6 is a sectional view of a sixth embodiment F of the building board according to the present invention, in which the reinforcing material is provided on both sides of the board. That is, the plywood 14 is bonded to the upper and lower surfaces of the base material 11 as a reinforcing material, and then the moisture-proof layer 13 is formed on the surface of the plywood 14 and the side surface of the base material 11 as in the first embodiment. In this Example F, since the reinforcing material 14 is adhered to both surfaces of the base material 11, it is possible to construct without using distinction between the front and back sides when using it for a floor.

FIG. 7 is a sectional view of a seventh embodiment G of the building board of the present invention, which is a building board in which a reinforcing material and a moisture-proof layer are integrated. That is, in this example, a film-shaped reinforced plastic is bonded to the base material. Furthermore, in this example, a particle board with a thickness of 20 mm is used.
A sheet 15 in which a phenol resin is internally added to a 0.2 mm glass paper is attached to both sides of the cord 11.
The composite material 15 also serves as a reinforcing material and also serves as a moisture-proof layer. In addition to the above example, there is a method of using a resin as a moisture-proof layer and a net-shaped or woven fabric, a non-woven fabric, or the like as a reinforcement material to bond the reinforcement material and the moisture-proof material together. In addition, in some types of film, the film alone serves as a reinforcing material and a moisture-proof layer.

As described above, when a net-like reinforcing material made of an organic fiber such as glass fiber, carbon fiber, polyester, acrylic, polypropylene, vinylon, and Kevlar is attached to a base material, In order to strengthen the adhesion with the core material, it is preferable to overlap a suitable non-woven fabric, paper or the like on the net to facilitate the internal addition of the adhesive or the resin to widen the adhesion area.

The bending strength test and the warp amount test of the board by repeated humidification were conducted on the construction board of the seventh embodiment G, and the results are shown in FIGS. 8 and 9. Here, the construction board of the seventh embodiment G is compared with other boards. As a comparative example, a particle board simple substance (P) having a thickness of 20 mm and a thickness of 18 mm is used. Board (Q) with a 2.3 mm plywood attached to the pull side, thickness 2
(R) with a glass fiber woven fabric in the substrate at 0 mm.

The bending strength test is performed according to the bending test method of JIS-A-1408, construction boards, and the size of the test piece is 30 cm × 25 cm (No. 4), and the load span is 2
It was 5 cm.

In the board warp amount test by repeated humidification, the same board as the above test was used, and the maximum value (cm) of the arrow height dimension at the center of the board was measured. The test conditions were that each board atmosphere was repeatedly loaded with relative humidity of 40% and 90% every 100 hours.

When the boards Q and R have the same thickness, as shown in the graph of FIG. 8, a bending strength about twice or more that of the board P is obtained. Has been. However, on the other hand, in addition to the above-described strength required for a floor, it is particularly required that the amount of warp (the amount of dimensional change) of the floor material due to repeated humidification is small.

FIG. 9 shows a comparison of the warp amount (diagonal direction) of the board due to the repeated humidification. The size of the board is 900
mm × 1800 mm, and the maximum amount of change in the arrow height dimension h in the diagonal direction was measured as shown in FIG. As can be seen from this figure, the warp amount of the wood-based core material board (R) in which the glass fiber woven fabric is inserted is significantly larger than that of the single board P. Especially, humidity (30 ° C x relative humidity 90
%), The amount of change in warpage is large.

The reason for this is that, as shown in FIG. 10, the base material tends to expand by absorbing moisture from both sides of the wood-based core material board, but on the side containing the glass fiber fabric, this fabric is the base material. This is the same for the board Q as well, since a large amount of warpage occurs due to the increase in elongation on the side not containing the fabric.

Therefore, when these boards Q and R are used for the floor, even if an extremely heavy object is placed, the strength is satisfactory, but the moisture from the concrete frame and the moisture pool under the floor are accumulated. This may cause the floor to warp, causing the so-called floor to fall apart. In particular, when the concrete skeleton was not completely dried, this tendency was strong and it was not put to practical use. As can be seen from the test results, the bending strength of the wood-based core material board (building board) of the present invention is stronger than any of the other boards, and the dimensional change is extremely small and stable. BO
It was proved that he was able to provide.

FIG. 11 is a sectional view of an eighth embodiment H of the building board of the present invention.
The moisture-proof layer 13 is formed in the same manner as described above, and then a reinforcing material made of plywood 12 is attached to one side of the moisture-proof layer 13.

FIG. 12 is a sectional view of a ninth embodiment I of the building board of the present invention. The difference from the previous example is that the plywood 14 is attached to both sides of the board 11.

[0032]

As described above in detail, when the wood-based core material board of the present invention is used as, for example, a construction board, it can withstand a super load and is in an atmosphere for humidity. However, the warp amount is remarkably smaller than that of the conventional board, and the board is particularly suitable as a floor to be laid on the concrete surface.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment A of a wood-based core material board of the present invention.

FIG. 2 is a sectional view of a second embodiment B of the building board of the present invention.

FIG. 3 is a cross-sectional view of a third embodiment C of the wood-based core material (for construction) board of the present invention.

FIG. 4 is a sectional view of a fourth embodiment D of the building board of the present invention.

FIG. 5 is a sectional view of a fifth embodiment E of the building board according to the present invention.

FIG. 6 is a cross-sectional view of a sixth embodiment F of the building board of the present invention.

FIG. 7 is a sectional view of a seventh embodiment G of the building board of the present invention.

FIG. 8 is a graph showing the relationship between bending and bending strength of a wood-based core material board.

FIG. 9 is a graph showing the relationship between the elapsed time of a wood-based core material board and the amount of change in arrow height dimension due to repeated humidification.

FIG. 10 is a side view of a wood-based core material board showing a warp change.

FIG. 11 is a sectional view of an eighth embodiment H of the building board of the present invention.

FIG. 12 is a sectional view of a ninth embodiment I of the building board of the present invention.

FIG. 13 is a side view showing a case where a wood-based core material board is bent due to a load applied thereto.

[Explanation of symbols]

1 ... Wood-based core material board, 1a ... Wood-based core material board compression side, 1b ... Wood-based core material board tension side, 1c ... Wood-based core material board Neutral surface, 2 ... Plywood, 3 ... Glass fiber woven fabric, 11 ... Wood-based core board base material, 12 ... Glass fiber woven fabric, 13 ... Moisture-proof layer, 14 ... Plywood, 15 ... ... composite material, A, B, C, D, E, F, G, H, I ... wood core material (for construction) board of the present invention, P ... particle board alone, Q ... A board with plywood attached to the particle board
A board having a glass fiber woven cloth in a particle board substrate.

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Claims (9)

[Claims] 1. A structure of a wood-based core material board, characterized in that a surface material is attached to both surfaces of the wood-based core material board to modify the board. 2. A wood-based core material board is a particle board.
2. The structure of a wood-based core material board according to claim 1, which is a board, a wafer board, or a wood-based fiber board. 3. The structure of a wood-based core board according to claim 1, wherein the surface material is a woven cloth or a non-woven cloth, and is a layer impregnated with a thermosetting resin. 4. The structure of the wood-based core material board according to claim 3, wherein a filler is mixed in the thermosetting resin. 5. The structure of a wood-based core material board according to claim 1, wherein the surface material is a synthetic resin layer. 6. The structure of the wood-based core material board according to claim 1, wherein a tensile strength-reinforcing material is disposed on at least one surface of the wood-based core material board surface or inside thereof. 7. The structure of a wood-based core material board according to claim 6, wherein a moisture-proof layer is provided as a surface material on both surfaces of the wood-based core material board. 8. The structure of a wood-based core material board according to claim 6, wherein the tensile strength-reinforcing material is larger than the Young's modulus of the wood-based core material board base material. 9. The structure of a wood-based core material board according to claim 6, wherein a moisture-proof layer is also provided on a side surface of the wood-based core material board.