JP2010001704A - Decorative plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a decorative plate having excellent dimensional stability, less extensible even if the decorative plate absorbs or releases moisture, and manufactured with due considerations to the shortage of wood resources. <P>SOLUTION: This decorative plate 1 is formed by laminating a wooden base member 2, a surface layer member 3 joined to the front surface of the base member, and a rear layer member 4 joined to the rear surface of the base member. A resin decorative layer 5 is installed on the surface of the surface layer member. The surface layer member is formed of a medium density fiber board. The rear layer member is formed of a kenaf board manufactured by fixing kenaf fibers with a binder. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a decorative board material in which a woody base material, a surface layer material attached to the front surface side of the base material, and a back layer material attached to the back surface side of the base material are laminated.

Conventionally, as a decorative board material used for interior building materials and furniture of a residence, a wooden board material such as plywood, particle board, insulation board is used as a base material, and the outer surface (front and back surfaces, side end faces ( A material having a surface material attached to a front end) is widely used.
FIG. 3 is a partially enlarged cross-sectional view schematically showing an example of a conventional decorative board material, and shows problems of the conventional decorative board material.
The decorative board material 100 shown here has medium density fiber boards 300, 400 (hereinafter referred to as MDF (Medium Density Fiberboard)) bonded to the front and back surfaces of a base material 200 made of plywood, and the MDF 300 on the front surface side is for moisture prevention. The resin decorative sheet 500 is attached.
However, if the decorative board material 100 as described above is left in a humid place such as a warehouse for a long time, the MDF 300 on the front side does not adsorb moisture because the resin decorative sheet 500 is adhered, The MDF 400 absorbs moisture and extends (see the direction indicated by white arrows in FIG. 3), and a concave warp occurs.
On the contrary, if the decorative board is left in a dry place for a long time, the surface MDF is still attached with the resin decorative sheet, so the surface does not dry, but the surface of the MDF on the back side is As the drying progresses, the MDF contracts and a convex warp (push-up) occurs (not shown) contrary to the above.
Thus, when a concave or convex warp phenomenon occurs due to a change in humidity, the construction may be affected, which is a problem.
In recent years, due to problems such as depletion of wood resources, consideration for resource protection is required for the materials used for decorative board materials.

In Patent Document 1 below, in order to solve the above-described problem, a fiberboard made of long fibers having a length of 100 to 4000 mm obtained from at least one of kenaf, oil palm, and coconut, A long fiber mat comprising a resin decorative sheet bonded to at least one surface is disclosed. Stair tread obtained by laminating the above-mentioned long fiber mats on the top and bottom of a particle board (base material) made of a particle mat obtained by pulverizing a kenaf bast (see Patent Document 1 and FIG. 8 (b)) According to the above, it is said that deformation in the thickness direction due to a warp phenomenon such as warp or push-up can be suppressed.
JP 2002-038679 A

As in Patent Document 1, when the resin decorative sheet is attached to both sides of the step board for staircases, it is possible to prevent changes in expansion and contraction due to moisture and the above-mentioned warping phenomenon. Since many of the used materials are not provided with a surface finish on the back side, measures against moisture at that time are problematic.
In addition, when using particle board instead of plywood as the base material, the bending strength cannot be satisfied in many cases, so the back layer material to be attached to the back side is a board made of high-strength kenaf fiber with a binder. It can be said that a kenaf board is suitable. Furthermore, the kenaf board has characteristics that it has excellent dimensional stability and does not expand or contract even when moisture is absorbed and released.
On the other hand, as the surface layer material stuck to the surface side of the base material, smoothness and appropriate surface hardness are required, and therefore the above-mentioned MDF can be said to be preferable to the kenaf board.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a decorative board material that is excellent in dimensional stability, has little expansion and contraction even when moisture is absorbed and released, and is considered to be short of wood resources.

In order to achieve the above object, a decorative board material according to the present invention includes a wooden base material, a surface layer material attached to the front surface side of the base material, and a back layer attached to the back surface side of the base material. A decorative sheet material is formed by laminating a material, and a resin decorative layer is formed on a surface of the surface layer material, the surface layer material is made of a medium density fiberboard, and the back layer material is a kenaf fiber binder. It consists of a kenaf board that is made into a board.
The decorative board material can be used for interior building materials, furniture, etc. in homes, interior materials, flooring materials, ceiling materials, door frame materials, door materials, treads, shelves, kitchen and washstand cabinets, various furniture components, etc. Can be used.
Here, the medium density fiber board is a so-called MDF having a density of 0.35 g / cm ³ or more and less than 0.80 g / cm ³ , and may be called a medium fiber board.
The kenaf board can be manufactured as follows. First, the kenaf bast is defibrated, cut and deposited so as to have a fiber length of 6 mm or longer, and laminated to produce a long fiber mat body. Then, an adhesive is uniformly dispersed in the long fiber mat body and introduced into a hot press machine, and a kenaf long fiber board manufactured by hot pressing (heat compression) is used as a kenaf board. An example of the manufacturing method will be described later.
The base material may be made of a particle board.
The particle board is compliant with JIS A 5908, and can be made of wood that has been hot-pressed by uniformly dispersing and mixing an adhesive with small pieces of wood such as waste. Moreover, the decorative board material of this invention can be used suitably for the step board for stairs.

The decorative board material according to the present invention is excellent in dimensional stability, does not expand or contract even when moisture is absorbed and released, and can effectively prevent the warp phenomenon described above.
The surface layer material of the decorative board material according to the present invention is composed of a medium density fiberboard, and since a resin decorative layer is formed on the surface thereof, the resin decorative layer has a characteristic that it is easily stretched by moisture absorption and desorption. Expansion and contraction of the medium density fiberboard can be prevented.
Further, since the medium density fiberboard has excellent surface smoothness and is hard, the surface of the decorative board material can be smooth and hard.
Since the back layer material of the decorative board material according to the present invention is made of kenaf board, a resin decorative layer is applied to the surface of the back layer material, taking advantage of the non-stretching property even when placed in a humid or dry place for a long time. Even if it is not provided, the warp phenomenon as described above does not occur.
Therefore, the decorative board material as a whole can be provided with strength and hardness and excellent in dimensional stability. Furthermore, since the kenaf board uses kenaf, which is a first-year herb, it can be considered a shortage of wood resources and is inexpensive, so that the cost of the decorative board can be reduced.

  In the decorative board material of the present invention, when the base material is made of particle board, it can be made of an inexpensive board material, so that the cost of the decorative board material can be further reduced. In addition, even when using a particle board that does not have bending strength and rigidity, since the hard front and back layer material is used for the front and back, it has the bending strength and rigidity required for quality as a decorative board material. can do.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is an exploded perspective view showing a configuration of a decorative board material according to the present invention, and FIG. 2 is a schematic sectional view schematically showing the decorative board material.
The decorative board material 1 shown in the figure includes an intermediate particle board serving as a base material 2, a surface layer material 3 attached to the front surface side of the base material 2, and a back layer material attached to the back surface side of the base material 2. 4 is provided.
The particle board used as the base material 2 is a particle board manufactured in accordance with JIS A 5908, and is formed by hot-pressure molding by uniformly dispersing and mixing an adhesive with small pieces of wood (particles). It is good also as what used miscellaneous wood, woodworking waste, a waste material, etc. as a raw material as a small piece of wood. In this way, if the particle board is used as the base material 2, the cost can be reduced, and if the particle board formed using the waste material or the like is used, the wood resources can be effectively used, and the cost can be further increased. Reduction can be achieved.
Here, although the example which used the particle board as the base material 2 is described, it is not limited to this, Various wooden board | plate materials, such as a single board, a plywood, LVL, OSB, can be used.

As the surface layer material 3, MDF is used. The MDF is produced by uniformly dispersing and mixing a short fiber piece of wood having a length of less than 6 mm and an adhesive in accordance with JIS A 5905, and hot pressing. The
Since MDF is hot-press molded by mixing an adhesive with the above wood short fiber pieces, it is dense and excellent in surface smoothness, and has higher bending strength and peeling strength than the above-mentioned particle board, The surface of the decorative board material 1 can be made smooth and hard. In addition, since MDF has a high degree of freedom in design, it is possible to provide a decorative board material 1 having a good design property that can expand the range of selection by the user and obtain satisfaction.
A resin decorative layer 5 is formed on the surface of the surface layer material 3. According to this, since the surface of the MDF that easily expands and contracts due to moisture and drying is resin-coated by the resin decorative layer 5, moisture absorption and release can be prevented and expansion and contraction of the MDF can be suppressed.
The resin decorative layer 5 is formed by coating a surface of a surface material 3 with a resin sheet made of an olefin resin such as polyethylene terephthalate having moisture resistance, and bonding the surface with a moisture curable urethane adhesive or the like. Alternatively, an olefin resin material may be applied to form a coating film, which may be used as a resin decorative layer.

The back layer material 4 is a kenaf board made of kenaf fibers formed into a board with a binder, and is manufactured as follows, for example.
Kenaf bast, which is an annual herb of the mallow family, is defibrated so that the fiber diameter is about 20 μm to 500 μm, preferably about 50 μm to 100 μm, and is cut and deposited so that the fiber length becomes 6 mm or more. Laminate to make a long fiber mat body. This fiber length may be, for example, about 100 mm to 2000 mm. When the long fiber mat body is used, each of the kenaf long fibers may be oriented in substantially one direction or may be oriented in two directions substantially perpendicular to each other. 2a of FIG. 2 has shown the kenaf long fiber, In this figure, the example which orientated the kenaf long fiber in one direction is shown.
Then, the long fiber mat body, by uniformly dispersing an adhesive is introduced into the hot press, hot performed press (heating compression), density of 0.35g ^/ cm ³ ~1.20g ^/ cm 3 or so, ^preferably, to obtain a kenaf long fiber boards produced as the 0.50g / cm ³ ~1.00g / cm 3 or so, it can be a kenaf board.

The long fiber mat body may be dispersed by immersing the long fiber mat body in a liquid adhesive and squeezing with a roller or the like to adjust the mixing amount or mixing the powdered adhesive. It may be dispersed or mixed and dispersed by spray coating.
The mixing amount of the adhesive may be about 5% to 30% by weight, preferably 10% to 20% by weight, based on the total weight of the kenaf board.
The adhesive may be a thermosetting type resin adhesive such as urea resin, urea / melamine co-condensation resin, phenol resin and isocyanate resin.
The conditions for hot pressing are not particularly limited. For example, the pressing may be performed for a predetermined time under the conditions of a temperature of about 120 ° C. to 190 ° C. and a pressing pressure of about 1.0 to 4.0 MPa. The pressing time is appropriately set according to the plate thickness, the density of the kenaf board after molding, and the like.
As the kenaf board, instead of the above-mentioned kenaf long fiber board, a kenaf particle board may be formed by pulverizing the core part of the kenaf into small pieces with a hammer mill or the like, and uniformly dispersing the adhesive in the small pieces and performing hot pressure molding. . Or you may make it comprise a kenaf board by sticking and integrating a kenaf long fiber board on the front and back of such a kenaf particle board.
Such a kenaf board is disclosed in Japanese Patent Laid-Open No. 2000-246709.

  If the kenaf board is used, the resin decorative layer 5 is not formed on the surface of the back layer material 4 because the kenaf board does not stretch even when placed in a humid place or a dry place for a long time. In addition, it is possible to prevent a warp phenomenon due to moisture absorption / release. Moreover, since the resin decorative layer 5 should just be formed only in the surface side of the decorative board | plate material 1, compared with the thing of the patent document 1 mentioned above, a construction man-hour can be reduced and it can be set as a productive efficiency.

  As shown in FIG. 2, when the decorative board material 1 is used as a stepping board, the thickness t2 of the surface layer material 3 and the back layer material 4 is approximately the same thickness of 2 mm to 4 mm, and is 25 mm to 35 mm. It is assumed that the thickness of the base material 2 is thinner than the thickness t1, and the thickness of the decorative board material 1 is preferably 29 mm to 43 mm. When the plate thickness of the surface layer material 3 and the back layer material 4 is less than 2 mm, the plate material sandwiching the particle board as the base material 2 is too thin to meet the quality requirements of the decorative plate material 1 with respect to bending strength and rigidity. It becomes a thing. On the other hand, when the thickness of the surface layer material 3 and the back layer material 4 is greater than 4 mm, it can meet the quality requirements of the bending strength and rigidity as the decorative plate material 1, but the surface layer material 3 and the back layer material 4 Will be thicker than necessary.

Each of the surface layer material 3, the base material 2, and the back layer material 4 is bonded in a laminated state via an adhesive. As the adhesive, thermosetting resin adhesives such as water emulsion type such as vinyl acetate and synthetic rubber, urea resin, urea / melamine co-condensation resin, phenol resin and isocyanate resin can be used. .
According to this, since inexpensive MDF, particle board, and kenaf board can be used as a board material, the cost reduction of the decorative board material 1 can be achieved. In addition, even when using a particle board that does not have bending strength and rigidity, since the hard front and back layer materials 3 and 4 are used for the front and back, the one having the bending strength and rigidity required for quality can do. Therefore, it can be suitably used as a step board for stairs.

Next, an example of a decorative board material according to the present invention will be described in comparison with a comparative example.
Example 1
The decorative board material 1 is produced by setting the board thickness t1 of the substrate 2 to 30 mm and the board thickness t2 of the surface layer material 3 and the back layer material 4 to 3 mm (see FIG. 2). The length of the decorative board material 1 shall be 870 mm.
Particle board was used as the base material 2, MDF was used as the surface layer material ³ , and kenaf board having a density of 0.9 g / cm ³ was used as the back layer material 4.
The surface of the back layer material 4 and the surface of the base material 2 are coated with a vinyl acetate adhesive in an amount of 20 g / angle, and the base material 2 is coated on the back layer material 4 and the surface layer material 3 is coated on the base material 2. Lamination was performed and a cold pressure of 8 kg / cm ² was pressed for 1 hour. Then, an olefin-based resin decorative sheet was placed on the surface of the surface layer material 3 and laminated with PUR to form the resin decorative layer 5, and the decorative board material 1 was obtained. Here, PUR is a reactive hot melt adhesive mainly composed of a polyurethane resin.

(Comparative example)
A decorative board material having a board thickness similar to that of the above-described embodiment is manufactured by setting the board thickness t1 of the base material to 30 mm and the board thickness t2 of the surface layer material and the back layer material to 3 mm. The length of the decorative board material 1 shall be 870 mm.
Particle board was used as the base material, and MDF was used as the surface layer material and the back layer material. The particle board and MDF used here are the same as those in the above-described embodiment.
A vinyl acetate adhesive of 20 g / scale angle is applied to the surface of the back layer material and the surface of the base material, the base material is laminated on the back layer material, and the surface layer material is laminated on the base material, and 8 kg / cm. A cold pressure of ² was pressed for 1 hour. Then, an olefin-based resin decorative sheet was placed on the surface of the surface layer material and laminated with the PUR to form the resin decorative layer 5 to obtain a decorative plate material.

(Evaluation measurement and measurement results)
The decorative board material 1 of the example obtained in this way and the decorative board material of the comparative example were exposed for about three weeks until the weight became constant in an atmosphere of a temperature of 40 ° C. and a humidity of 90%, and then the thickness direction (width) of the decorative board material 1 The direction of warping was measured with a steel ruler.
As a result of the measurement, for the decorative plate material having a length of 870 mm, in the comparative example, a warp of 3.0 mm was measured in a concave shape, whereas in the decorative plate material 1 of the example, a warp of 0.5 mm was measured in a concave shape. It was.
From the above, it was confirmed that the decorative board material of the comparative example had a warp affecting the construction, but the decorative board material 1 of the example had a slight warpage of 0.5 mm (1/6 of the warp of the comparative example). It can be said that there is no possibility of affecting construction.
Thus, by the evaluation measurement, the front side of the decorative board material 1 prevents moisture from being adsorbed by the resin decorative layer 5, and the back side uses a kenaf board even if moisture is adsorbed. Since the dimensional change of the base material 2 made of particle board is small and less, the warp phenomenon can be effectively prevented as compared with the comparative example.

It is a disassembled perspective view which shows the structure of the decorative board material which concerns on this invention. It is a schematic sectional drawing which shows typically the decorative board | plate material which concerns on this invention. It is an expanded sectional view showing typically the curvature phenomenon of the conventional decorative board material.

Explanation of symbols

1 decorative board material 2 base material 3 surface layer material 4 back layer material 5 resin decorative layer

Claims (3)

It is a decorative board material formed by laminating a woody base material, a surface layer material attached to the front surface side of the base material, and a back layer material attached to the back surface side of the base material,
A resin decorative layer is formed on the surface of the surface material,
The decorative board material, wherein the surface layer material is made of a medium density fiber board, and the back layer material is made of kenaf board obtained by making kenaf fibers into a board with a binder. In claim 1,
The decorative board material, wherein the base material is made of particle board. In claim 1 or claim 2,
A decorative board material, characterized in that it is used as a tread board for stairs.

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