JPH0754467A - Decorated board and production thereof - Google Patents

Abstract

PURPOSE:To obtain at low cost a decorated board excellent in various characteristics such as adhesive force between the base board and the decorated singular plate, waterproof, durability, resistance against drying and cracking, shock resistance, surface strength, etc. CONSTITUTION:A wooden fiber plate having hard layers 2a, 2b with a high specific gravity at least at the surface is used for a base board 1. A decorated singular plate 3 is stuck through an adhesive at the surface thereof. Since the hard layer 2a is existing on the surface, the adhesive is prevented from excessively permeating into the base board and a part of adhesive permeates from the rear side of decorated plate and forms a layer 4 immersed with the adhesive at the rear face of decorated plate. A thermosetting resin is applied on the surface of decorated singular plate. As the resin is cured, an impregnated thermosetting resin layer 5 is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decorative board in which a decorative veneer is attached to the surface of a substrate and a method for producing the same, and more particularly, a decorative board having a hard surface by impregnation with a synthetic resin and a method for producing the same. Regarding

[0002]

2. Description of the Related Art A decorative veneer is obtained by placing a decorative veneer in a pressure and decompression device, injecting a synthetic resin, impregnating the synthetic veneer into the decorative veneer and curing it. Then, the resin-impregnated decorative veneer is attached to a substrate via an adhesive to form a decorative plate.

Since the decorative veneer thus constructed is impregnated with synthetic resin throughout the decorative veneer, the decorative veneer is made harder, and wear resistance and resistance as a decorative veneer are improved. The sun cracking properties are being improved.

[0004]

However, according to this conventional method, resin impregnation is carried out by using a pressurizing and depressurizing device, so that large-scale equipment is required. Moreover, since the productivity is low and the synthetic resin is impregnated throughout the decorative veneer, it is necessary to use a large amount of the synthetic resin. Due to these factors, the manufacturing cost was inevitably high.

Further, since the synthetic resin is left on the front and back surfaces of the decorative veneer, the adhesive is prevented from penetrating into the decorative veneer when it is adhered to the substrate, and the anchoring effect cannot be expected. There was a drawback that it could not obtain good adhesive strength. In order to solve this, it is necessary to obtain the adhesive force due to the intermolecular attractive force using a synthetic resin adhesive of the same type as the synthetic resin used for impregnation, which further increases the cost.

[0006]

Therefore, the present invention solves the above-mentioned problems in the prior art, improves the adhesive force of a decorative veneer to a substrate while using a simple device, and It is an object of the present invention to provide a decorative sheet having improved surface properties and excellent abrasion resistance, day cracking resistance, impact resistance, water resistance and the like.

That is, the decorative board according to the present invention comprises a board made of a wood fiber board having a hard layer having a high specific gravity on at least the surface of the board, and a decorative veneer attached to the hard layer via an adhesive. An adhesive impregnated layer in which the adhesive is impregnated and cured is formed on the back side of the decorative veneer, and a thermosetting resin impregnated layer in which a thermosetting resin is impregnated and cured is formed on the front side. Is characterized by.

The wood fiber board used as the substrate preferably has an overall specific gravity of 0.4 or more, but a hard layer having a specific gravity higher than that of the inner layer portion is exposed and formed on one surface or both surfaces thereof. This hard layer preferably has a specific gravity of 0.8 to 1.4 and a layer thickness of about 0.3 to 1.0 mm.

Since the hard layer has a higher specific gravity than the inner layer portion of the wood fiberboard, the wood fiberboard itself has tensile strength,
It excels in compressive strength and bending strength, and has a very small amount of bending deflection, which improves the strength of the decorative sheet. Further, the hard layer on the surface imparts water impermeability.

The wood fiberboard having the hard layer of high specific gravity on at least the surface thereof as described above can be manufactured as follows. That is, for example, in the manufacturing process by the dry method, pine, cedar, wood chips such as softwood materials such as cypress, Kapole, Lauan, chestnut, poplar and the like, or defibrate waste wood chips such as construction, or sander dust, Properly mix wood flour such as sawdust to obtain wood fiber,
An adhesive, a sizing agent, and the like are added to the wood fibers and then dried, the wood fibers are deposited on a screen conveyor by a forming device, and temporarily pressed to form a wood fiber mat.
Next, the wood fiber board is obtained by cutting it into a certain size to form a standard length wood fiber mat and then heat-pressing it.

In this manufacturing process, a hard layer is formed on one side or both sides of the obtained wood fiber board by increasing the amount of the adhesive added to the wood fiber or increasing the water content of the wood fiber, and The layer thickness of the hard layer can be increased.

The upper surface of the standard length wood fiber mat and / or
Alternatively, water is applied to the lower surface, or a water-retaining sheet-like material such as non-woven fabric, paper, or cloth is hydrated and placed on the upper surface and / or the lower surface of the wood fiber mat, and heat-pressed in this state. To do. As a result, heating and pressing are performed in a state where the water content of the front and back portions is increased, so that a hard layer having a large layer thickness is formed on the water application surface or the mounting surface side of the sheet-shaped material.

In this case, the hard layer can be formed by adjusting the amount of water applied, the amount of water contained in the sheet, or the amount of the adhesive added to the wood fibers and the water content of the wood fibers. A desired specific gravity and layer thickness can be given.

In this way, a wood fiber board having a hard layer having a predetermined thickness on one or both sides is obtained. In this wood fiber board, a thin surface layer having a low specific gravity due to the precure of the adhesive at the time of heating and pressing. Therefore, if necessary, at least the surface side is sanded to remove the low specific gravity thin surface layer, and the hard layer is exposed on the surface.

If necessary, the surface hard layer of the wood fiber board is subjected to a base treatment such as a sealing treatment, a sealer treatment, and an abrasion resistance treatment, and then a coating device (roll coater, flow coater, curtain coater, spreader, Apply the adhesive using a spray or the like).

As the adhesive, vinyl acetate resin, urea resin, melamine resin, phenol resin, acrylic resin,
A synthetic resin such as polyester resin, polyurethane resin, isocyanate, SBR, MBR, or a rubber-based adhesive is suitable, and these are used alone or in an arbitrary mixture. Moreover, you may use what modified | denatured these synthetic resin adhesives arbitrarily.

The amount of adhesive applied is 50 to 150 g / m ² ,
The viscosity is preferably 100 to 300 poise. The coating amount exceeds 150 g / m ² and the viscosity is 10
If it is less than 0 poise, the applied adhesive will exude to the surface of the decorative veneer to which the adhesive is applied, and impede the press-fitting and impregnation of the subsequently applied thermosetting resin into the decorative veneer. However, when the same type of synthetic resin is used as the adhesive and the thermosetting resin, a sufficient adhesive force can be obtained due to the intermolecular attractive force between them, and this is not the case.

Further, if the coating amount is less than 50 g / m ² or the viscosity exceeds 300 poise, it becomes difficult to press-fit and impregnate the coated adhesive into the decorative veneer, so that the substrate and the decorative veneer are separated. Adhesive force between them cannot be obtained sufficiently.

Next, a decorative veneer is placed on the surface of the substrate coated with the adhesive. As the decorative veneer, a slice veneer, a sword veneer, a rotary veneer, a half-land veneer, an artificial veneer, etc. are used, and those having a thickness of about 0.1 to 2.0 mm are generally used. As the decorative veneer, a sheet-like material such as a non-woven fabric, thin paper, or kraft paper which does not prevent the pressure-impregnation of the adhesive from being adhered to the back side and backed may be used.

Next, the substrate on which the decorative veneer is placed is placed in a pressing device (roll press, flat plate press, etc.) to be hot-pressed or cold-pressed, and the decorative veneer is bonded to the substrate via an adhesive. Stick on the surface. At this time, since a wood fiberboard having a hard layer with a high specific gravity formed on at least the surface is used as the substrate, the adhesive is applied from the surface of the wood fiberboard to the inside even when hot-pressing or cold-pressing with a pressing device. It is not impregnated more than necessary and even with a small amount of adhesive applied,
The adhesive impregnated layer can be formed by effectively press-fitting and impregnating a part thereof from the back surface side of the decorative veneer. Thus, sufficient adhesive strength can be obtained between the decorative veneer and the substrate surface.

Next, using a coating device (roll coater, flow coater, curtain coater, spreader, spray, etc.) on the surface of the decorative veneer adhered to the substrate,
Apply thermosetting resin. Examples of the thermosetting resin include a phenol resin, a urea resin, a melamine resin, an epoxy resin, and a polyurethane resin, and these can be used alone or in an arbitrary mixture. Moreover, you may use what modified | denatured these thermosetting resins arbitrarily.

The coating amount of the thermosetting resin is 30 to 150 g /
m ² , and its viscosity is preferably 0.2 to 3.0 poise. If the coating amount is less than 30 g / m ² or the viscosity is less than 0.2 poise, the thermosetting resin-impregnated layer formed on the surface of the decorative veneer cannot have a sufficient layer thickness. Effects such as improvement of surface strength and durability cannot be sufficiently obtained. Moreover, the coating amount exceeds 150 g / m ² ,
If the viscosity exceeds 3.0 poise, not only the cost will increase, but also the thermosetting resin will exude onto the surface of the decorative veneer during pressing and contaminate the decorative plate and the hot plate of the pressing device. Therefore, it is not preferable.

After the thermosetting resin is applied, the thermosetting resin is put into a flat plate pressing machine and heated and pressed between the upper and lower pressing plates to press-inject the thermosetting resin onto the surface of the decorative veneer to cure it and impregnate it with the thermosetting resin. Form the layers.

The decorative plate of the present invention is obtained by the above steps. In this decorative board, an adhesive impregnated layer is formed on the back side of the decorative veneer attached to the surface of the substrate, and a thermosetting resin impregnated layer is formed on the front side of the decorative veneer. Since it is impregnated, various properties such as surface strength, water resistance, and dimensional stability are remarkably improved. Further, since the wood fiberboard having at least a hard layer on the surface is used as the substrate, the adhesive applied to the surface of the substrate for sticking the decorative veneer impregnates the wood fiberboard more than necessary. Even if the coating amount is small, a sufficient amount of the coating amount is impregnated into the decorative veneer, and the adhesive force between them is improved.

Furthermore, a transparent synthetic resin coating material can be applied to the surface of the decorative board using a coating device, and then dried to form a transparent protective film on the surface of the decorative veneer. As the transparent synthetic resin coating material, acrylic resin coating material, aminoalkyd resin coating material, vinyl resin coating material, epoxy resin coating material, polyurethane resin coating material and the like are preferably used. An optional colorant may be mixed with the transparent synthetic resin paint. Further, when inorganic particles such as aluminum oxide, silicon carbide, silicon oxide, borax, boron carbide and titanium oxide are mixed, a transparent protective coating having excellent wear resistance can be obtained.

Before applying the transparent synthetic resin paint, fine recesses can be formed on the surface of the decorative veneer by sanding, wire brushing or the like. As a result, the transparent synthetic resin coating material enters the fine recesses, and the adhesion is improved by the anchoring effect. In addition, isocyanate can be mixed with the transparent synthetic resin coating material for the purpose of improving adhesion.

[0027]

A wood fiber board having a hard layer having a high specific gravity formed on at least the surface is used as a substrate. Since the hard layer is present, the adhesive applied to the surface excessively penetrates into the substrate. There is nothing to do. Therefore, a sufficient amount of the applied adhesive is impregnated into the decorative veneer attached to the surface of the substrate via the adhesive to exert a large adhesive strength.

A thermosetting resin-impregnated layer is formed on the surface of the decorative veneer, and the surface strength, impact resistance, pressing resistance, abrasion resistance,
Various properties such as water resistance and dimensional stability are improved.

[0029]

【Example】

(Example 1) A wood fiber board having a specific gravity of 0.8 with a hard layer having a high specific gravity exposed on the front and back surfaces is used as a substrate, and an adhesive is applied to the surface of the substrate using a roll coater to a coating amount of 60 g / m ² . Applied. The adhesive used is a phenol-modified melamine resin adhesive, and wheat flour, an antifoaming agent, a penetrating agent, as an additive.
A curing agent and the like were mixed, and the viscosity was 200 to 250 poise.

Next, a 0.23 mm oak slice single plate is placed on the surface of the substrate and then placed in a hot press machine, pressure 7 kg / m ² , temperature 130 ° C., clamping time 60.
It was hot pressed under the condition of seconds. Thereby, a part of the adhesive was press-fitted into the back surface side of the sliced veneer and hardened to form an adhesive impregnated layer, and the sliced veneer was attached to the surface of the substrate with sufficient adhesive force.

A thermosetting resin was applied to the surface of the sliced veneer thus pasted on the surface of the substrate in a coating amount of 65 g / m ² using a roll coater. A phenol-modified melamine resin was used as the thermosetting resin, and its viscosity was 0.38 poise.

Immediately after the thermosetting resin is applied, the thermosetting resin is put into a hot press machine at a pressure of 7 kg / m ² and a temperature of 130.
Hot pressing was carried out under the conditions of ° C and a pressing time of 60 seconds. As a result, a part of the thermosetting resin was press-fitted and impregnated into the surface of the sliced veneer and cured, and a thermosetting resin-impregnated layer was formed.

A schematic structure of the decorative plate thus obtained is shown in FIG. 1, and hard layers 2a and 2b having high specific gravity are provided on the front and back surfaces.
A decorative veneer (slice veneer) 3 is attached to the surface of a substrate 1 made of a wood fiber board having a. The adhesive impregnated layer 4 is formed on the back surface side of the decorative veneer, and the thermosetting resin impregnated layer 5 is formed on the front surface side thereof. (Example 2) Colored transparent synthetic resin coating obtained by adding an isocyanate, a colorant, a penetrating agent and the like to polyester modified acrylic resin on the surface of the decorative board obtained in Example 1 using a roll coater. Coating amount of 50 g / m ²
Then, the mixture was placed in an ultraviolet irradiation device and cured by ultraviolet rays to form a transparent protective film.

A schematic structure of the decorative board thus obtained is shown in FIG. 2, which is a decorative board in which a transparent protective film 6 is further formed on the decorative veneer 3 in the decorative board of FIG. (Example 3) The decorative plate obtained in Example 1 was put into a sanding device, and the surface of the sliced veneer was sanded to form fine recesses. Sandpaper with count # 240 to # 400 was used for sanding. This is because when the count is rougher than # 240, the recess formed on the surface of the sliced veneer becomes wider and deeper and the surface is roughened. Conversely, when the count is thinner than # 400, the recess is formed. The width is too narrow and too small, and the effect of anchoring the paint applied later cannot be expected.

A colored transparent synthetic resin paint obtained by adding a coloring agent, a penetrating agent, etc. to a polyester-modified acrylic resin by using a sponge coater on the surface of the sliced veneer on which the fine recesses are formed, After coating with a coating amount of 50 g / m ^{2, the} coating was placed in an ultraviolet irradiation device and ultraviolet-cured to form a transparent protective film.

The decorative plate thus obtained is substantially the same as that shown in FIG. 2, except that the transparent protective film 6 is anchored in the fine recesses on the surface of the decorative veneer 5 to bond them. The power was increased.

[0037]

According to the present invention, since the hard layer is formed on the surface of the wood fiber board which is the substrate to prevent the adhesive from excessively permeating, the surface of the substrate is used for attaching the decorative veneer. A sufficient adhesive force can be obtained between these even if the amount of the adhesive applied to is small, and a decorative board excellent in peel strength can be provided at low cost.

Further, since the hard layer on the surface of the substrate hardly absorbs water and has a small expansion and contraction, the decorative veneer is not cracked, swollen, or wrinkled. Further, the surface strength is improved.

Further, the decorative veneer has an adhesive impregnated layer on the back side and a thermosetting resin impregnated layer on the front side and is resin impregnated, so that the surface strength, impact resistance and pressure resistance are high. Properties, day cracking resistance, wear resistance, water resistance, etc. are greatly improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration example of a decorative board of the present invention.

FIG. 2 is a cross-sectional view showing another configuration example of the decorative board of the present invention.

[Explanation of symbols]

 1 Wood fiber board (substrate) 2a, 2b Hard layer 3 Decorative veneer 4 Adhesive impregnation layer 5 Thermosetting impregnation layer 6 Transparent protective coating

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B32B 33/00 7148-4F E04F 13/08 A 9127-2E

Claims (6)

[Claims] 1. A decorative veneer is attached to the hard layer of a substrate made of a wood fiber board having a hard layer having a high specific gravity on at least the surface via an adhesive, and the decorative veneer is provided on the back surface side. Is a thermosetting resin impregnated layer in which a thermosetting resin is impregnated and cured, and a thermosetting resin impregnated layer in which a thermosetting resin is impregnated and cured is formed on the surface side. 2. A decorative veneer is adhered to the hard layer of a substrate made of a wood fiber board having a hard layer having a high specific gravity on at least the surface via an adhesive, and the decorative veneer is provided on the rear surface side. Is formed with an adhesive impregnated layer in which the adhesive is impregnated and cured, and a thermosetting resin impregnated layer in which a thermosetting resin is impregnated and cured is formed on the surface side. A decorative board characterized in that a transparent protective film is formed on. 3. The fine concave portion is formed on the surface of the decorative veneer, and the transparent protective film is anchored in the fine concave portion to enhance the adhesive force between them. Veneer. 4. A wood fiber board having a hard layer having a high specific gravity on at least the surface is used as a substrate, an adhesive is applied on the hard layer, and a decorative veneer is placed on the adhesive-coated surface and pressed. Then, a part of the adhesive is impregnated and cured in the decorative veneer to form an adhesive impregnated layer on the back side of the decorative veneer, and the decorative veneer is attached to the substrate. A thermosetting resin is applied to the surface of the veneer, and pressure is applied between the upper and lower pressing plates to impregnate the surface of the decorative veneer with the thermosetting resin and cure the thermosetting resin on the surface side of the decorative veneer. A method for manufacturing a decorative board, which comprises forming an impregnated layer. 5. A wood fiber board having a hard layer having a high specific gravity on at least the surface is used as a substrate, an adhesive is applied on the hard layer, and a decorative veneer is placed on the adhesive-coated surface and pressed. Then, a part of the adhesive is impregnated and cured in the decorative veneer to form an adhesive impregnated layer on the back side of the decorative veneer, and the decorative veneer is attached to the substrate. A thermosetting resin is applied to the surface of the veneer, and pressure is applied between the upper and lower pressing plates to impregnate the surface of the decorative veneer with the thermosetting resin and cure the thermosetting resin on the surface side of the decorative veneer. A method for producing a decorative board, which comprises forming an impregnated layer, and further applying a transparent synthetic resin paint onto the decorative veneer to dry it to form a transparent protective film. 6. The method for manufacturing a decorative board according to claim 5, wherein fine concave portions are formed on the surface of the decorative veneer before applying the transparent synthetic resin paint.