JPH06322950A - Board for building - Google Patents

Abstract

PURPOSE:To provide a board for use in building covered with a decorative sheet having good dimensional stability, particularly a laminated sheet of novel construction usable as a substitute for a plywood and to improve dimensional stability and construction efficiency in a board for building wherein the laminated sheet is used as a base board. CONSTITUTION:As a base board 1 for a board for building for use as a floor material, a laminated sheet which is prepared in such a manner that a surface wood fiber layer 2, an intermediate wood single layer 3, and a rear wood fiber layer 4 are layered successively from the front surface side into a one-piece construction is used, and a decorative sheet 5 is bonded to the front surface of the laminated sheet and a moisture-proof sheet 9 is bonded to the rear surface thereof. The sheet 9 has a three-layer construction wherein a polyethylene sheet 7 is a core layer and craft sheets 6, 8 are layered respectively over the front and rear sides of the sheet 7, and the front surface craft sheet 6 is bonded to the layer 4 on the rear surface of the base board 1, while the rear surface craft sheet 8 is bonded to the surface of the ground under a floor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a building board used as a floor material, a ceiling material, a wall material, etc. of a house.

[0002]

2. Description of the Related Art As a construction board used for the above-mentioned purposes, there is known a construction board in which an arbitrary decorative sheet such as a veneer is attached to the surface of the board. As the substrate, a plywood obtained by laminating and bonding single plates with their fiber directions orthogonal to each other, or a parallel plywood (LV.
L. ) Is commonly used. Since these plywoods can stably supply a large amount of large-sized boards and are excellent in dimensional stability, they have been suitable as substrates for construction boards used for flooring and the like.

[0003]

These plywoods are manufactured by laminating and adhering veneers made by thinly stripping natural wood. In recent years, the problem of depletion of natural resources has been widely taken up worldwide, and As it becomes increasingly difficult to cut down the raw wood that is the raw material, and the quality of the raw wood deteriorates, it is becoming difficult to stably obtain a large amount of good quality veneer suitable for plywood. . For this reason, it has become difficult to stably supply a large amount of high-quality plywood to the market as it used to. This problem is expected to become more and more serious in the future, and there is an eager desire to provide an alternative product that can be used in place of plywood as a base material for building boards.

Further, when it is used as a floor material which is directly pasted on a concrete foundation at a construction site such as a condominium, the concrete itself does not remain even after the primary hardening of the concrete is completed and the concrete has sufficient strength. Due to the high water content, this moisture tends to be absorbed by the back side of the flooring substrate and cause the back side to expand, while a decorative sheet with a surface coating is generally attached to the front side. As a result, water is hardly absorbed from the surface side. Therefore, there is a problem in that the expansion rates of the front surface side and the back surface side of the floor material are different, and warpage occurs in which the back surface side is convex in the width direction of the floor material. This problem is not limited to the case of directly pasting on a concrete substrate, but it occurs to a greater or lesser extent due to an increase in humidity in the environment in which the floor material is constructed.

[0005]

Therefore, the present invention has a good dimensional stability, and in particular, a building having excellent dimensional stability even when a novel laminated plate which can be used as a substitute for plywood is used as a substrate. It was completed after intensive efforts to provide a board.

That is, in the construction board according to the present invention, a polyethylene sheet is used as a core on the back surface of a substrate formed by laminating a surface wood fiber layer, a middle wood veneer layer and a back wood fiber layer in this order from the front surface side. It is characterized in that a moisture-proof sheet formed by laminating kraft paper is attached to the front and back thereof.

As the wood veneer used for the middle-layer wood veneer layer in the substrate in this case, a softwood veneer or a hardwood veneer obtained by cutting a conifer or a hardwood log with a cutting device such as a rotary racer or a slicer. Plates can be used. These softwood veneers and hardwood veneers have a thickness of 0.
2 mm or more, preferably 0.5 to 5.5 mm is used. If the plate thickness is less than 0.2 mm, it is difficult to give a mechanical strength required for a building board, especially when it is used as a floor material. From this viewpoint, the plate thickness may be 0.5 mm or more. preferable. If the plate thickness exceeds 5.5 mm, the shrinkage and expansion of the veneer due to moisture absorption and release will affect the dimensional stability of the substrate.
Not preferable.

The wood veneer used for the middle-layer wood veneer layer is subjected to phenol resin treatment, acetylation treatment, esterification treatment, formalization treatment, PEG (polyethylene glycol) treatment, WPC (resin impregnation) treatment, etc. It is possible to improve the dimensional stability and mechanical properties of the substrate. Further, by using a wood veneer that has been fire-proofed by a known flame-retardant agent such as ammonium phosphate, a phosphorus-nitrogen compound, a halogen compound, sulfamic acid, and boric acid, a building board that also has a fire-proof function can be obtained. To be This fire prevention treatment is, for example, a method of immersing the wood veneer in the flame retardant chemical, a method of applying the flame retardant chemical to the surface of the wood veneer, or applying the flame retardant chemical to the wood veneer under pressure or reduced pressure. This can be done by the method of injection.

On the other hand, the surface wood fiber layer and the back wood fiber layer of the substrate are obtained by cutting softwood materials such as pine, cedar and cypress, or hardwood raw materials and waste materials such as Lauan, Kapole, chestnut and poplar. The obtained wood chips are defibrated by a conventional method to obtain a wood fiber, which is pressed to obtain a wood fiber layer having a specific gravity of 0.4 or more, preferably 0.5 or more. , MDF (medium quality fiberboard) and the like. Waste materials such as sander dust, saw dust, and chip dust generated in the manufacturing process can be mixed in the wood fiber layer. The surface wood fiber layer and the back wood fiber layer may have the same or different thicknesses, and may have the same or different specific gravities.

Such a wood fiber layer has a very small dimensional change rate of 0.03 to 0.04% per 1% of water content, and is substantially uniform in any direction, and has excellent dimensional stability. Have. Therefore, by forming the substrate by interposing the middle-layer wood veneer layer between the surface wood fiber layer and the back wood fiber layer, the contraction and expansion of the middle-layer wood veneer layer is suppressed by these front and back wood fiber layers. Therefore, it is possible to obtain a substrate having extremely excellent dimensional stability. Incidentally, the rate of dimensional change due to moisture absorption / release of plywood is 0.02 to 0.03% per 1% of water content, so that the substrate used in the present invention has excellent dimensional stability comparable to plywood. It is understood that

The reason why the surface layer of the substrate is composed of the wood fiber layer is as follows. That is, since the wood fiber layer has a higher specific gravity and an excellent compressive strength than the wood veneer, good results can be obtained even in the iron ball drop test on the surface, and the load is locally applied by high heels or casters. This is because it has a characteristic that it is hard to be dented even if it is broken. Further, when the building board of the present invention is used as a flooring material, when a bending load acts on its surface, the surface wood fiber layer exhibits excellent compression resistance performance against the load of compression generated on the surface side. The flooring material has excellent bending strength in the length direction and the width direction. Furthermore, due to the excellent smoothness of the wood fiber layer, the finish is good when a decorative sheet is attached to the surface of the surface wood fiber layer or a coating treatment is performed.

In the wood fiber layers used for the surface wood fiber layer and the back wood fiber layer, as in the wood veneer used for the intermediate wood veneer layer, phenol resin treatment, acetylation treatment, esterification treatment, By performing formalization treatment, PEG treatment, WPC treatment, etc., the dimensional stability and mechanical properties of the substrate can be improved. These treatments can be carried out, for example, by a conventional method at the stage of defibrating and drying dried softwood chips or softwood chips according to a conventional method, and using the obtained treated wood fibers to produce a wood fiber layer. To do. Further, by producing a wood fiber layer using wood fibers that have been subjected to fire protection treatment with a known flame retardant agent such as ammonium phosphate, phosphorus nitrogen compounds, halogen compounds, sulfamic acid, boric acid, etc. A building board having is obtained.

In this way, as a decorative sheet to be attached to the surface of a substrate in which the surface wood fiber layer, the middle wood veneer layer and the back wood fiber layer are sequentially laminated from the surface side,
For example, a sliced veneer sheet backed by a sheet-like material such as a natural sliced veneer, artificial veneer, non-woven fabric, paper, synthetic resin sheet obtained by cutting natural wood having a thickness of about 0.2 to 3 mm, 20 to 40
g / ^{m 2} of decorative paper, of 32~500g / ^{m 2} non-woven fabric, 5
Examples include parchment paper of 0 g / m ^{2 and} the like, on which an arbitrary pattern pattern is printed or a single color is applied. These decorative sheets can be subjected to an arbitrary topcoating treatment after being attached to the substrate. For attaching the decorative sheet to the substrate surface, for example, a thermoplastic adhesive such as vinyl acetate resin,
It can be carried out using a mixture of thermosetting resin or urea powder for improving water resistance. Since the adhering surface of the decorative sheet is composed of a wood fiber layer (surface layer wood fiber layer) which is less likely to shrink and expand due to moisture absorption and release, even when a veneer sheet is used as the decorative sheet, the veneer is unlikely to crack.

A moisture-proof sheet having a polyethylene sheet as a core and kraft paper laminated on the front and back is attached to the back surface of the substrate. Such a moisture-proof sheet is obtained by laminating kraft paper on the front and back surfaces of a polyethylene sheet, followed by thermocompression bonding and heat fusion.

By using such a three-layer structure as the moisture-proof sheet, the polyethylene layer of the core layer prevents water absorption by the back-layer wood fiber layer in the substrate and the kraft paper on the front and back sides of the polyethylene sheet. The presence of the layer improves the adhesive strength of the adhesive to the back surface of the substrate, so that the layer can be easily attached using a general laminator device. Moreover, sufficient adhesive strength with the base surface can be obtained by applying an adhesive to the construction base.

By further adhering a sheet material having a cushioning function, such as a synthetic resin foam, a non-woven fabric, or a natural or synthetic rubber, between the substrate and the moisture-proof sheet or on the back surface of the moisture-proof sheet, the soundproofing performance and the heat insulating performance are obtained. Etc., or the walking feeling can be improved.

Further, as means for fitting adjacent construction boards to each other when constructing the construction board of the present invention, the side surface of the construction board may be subjected to actual machining or phase-shifting processing as required. Is processed.

The building board of the present invention is manufactured, for example, as follows. That is, prepared wood fiber board and wood veneer manufactured in advance, using the wood fiber board as the surface layer wood fiber layer and the back layer wood fiber layer and the wood veneer as the middle-layer wood veneer, these from the surface side Surface wood fiber layer,
The middle-layer wood veneer layer and the back-layer wood fiber layer are laminated and adhered via an adhesive in this order, and pressed according to a conventional method to obtain a substrate. Also, in the manufacturing process of the wood fiber board, using a wood fiber mat obtained by cutting and temporarily pressing the wood fiber dried by applying an adhesive by a forming device and depositing it on the screen belt to a certain size, The substrate can also be obtained by placing a wood veneer having an adhesive applied on the front and back surfaces on the wood fiber mat, and finally placing another wood fiber mat and then hot pressing. This method can use the existing production line of wood fiberboard as it is, and it can be pressed once (one shot).
It is industrially advantageous, and the adhesive strength between the wood fiber layer and the wood veneer layer in the obtained substrate becomes extremely large.

In addition, wood fibers are deposited on a screen belt, wood veneers are placed on the wood fibers, wood fibers are further deposited by a forming device, and then cut into a predetermined size, and then temporarily cut. Method of pressing by hot pressing or temporary pressing without cutting and continuously hot pressing and then cutting, after depositing wood fibers on the screen belt by a forming device, wood fibers on the wood fibers After placing a veneer, and then depositing another wood fiber on the wood veneer with a forming device, it is temporarily pressed and then hot pressed or temporarily pressed without cutting. The substrate having the structure of the present invention can be obtained by any method such as continuous hot-pressing and then cutting.

The decorative sheet is adhered to the front surface of the substrate thus obtained with an adhesive, and the moisture-proof sheet is adhered to the back surface with an adhesive to obtain the building board of the present invention. To be Further, when the wood fiber and the wood veneer are combined in the manufacture of the above substrate, the decorative sheet and / or the moisture-proof sheet may be simultaneously placed and laminated and then pressure-bonded.

[0021]

EXAMPLE FIG. 1 shows the structure of a flooring material as an example of a building board according to the present invention. From the surface side, a surface wood fiber layer 2, a middle wood veneer layer 3, a back wood fiber layer. The decorative sheet 5 is attached to the front surface of the substrate 1 which is laminated and adhered in the order of 4, and the polyethylene sheet 7 is attached to the back surface of the substrate 1.
With a core as a core, a moisture-proof sheet 9 having kraft papers 6 and 8 laminated on the front and back thereof is attached. In the figure, 10 is a male fruit,
Reference numeral 11 is a female fruit, and the floor material can be connected and constructed by fitting the male fruit and the female fruit to each other.

[0022]

EFFECTS OF THE INVENTION The building board according to the present invention has a decorative sheet adhered to the front surface of a substrate, and a moisture-proof sheet adhered to the back surface thereof. Balanced and warpage is prevented.

The present invention also proposes to use a laminated board having a novel structure in which a part of a veneer of plywood conventionally used as a substrate is replaced with a wood fiber layer. The layer is useful for effective use of resources and prevention of natural destruction because even a log having a defect that cannot be used as a veneer can be obtained by crushing or defibrating it into small pieces.

Since these wood fiber layers are originally excellent in dimensional stability and mechanical strength, even if they are used in place of a veneer, properties comparable to those of plywood can be obtained. Also, by arranging the wood fiber layers on the front and back of the middle-layer wood veneer, it is possible to exhibit extremely excellent dimensional stability and strength characteristics, especially in the length direction, and suitable for use as a flooring material. Becomes

Since the surface layer of the substrate is provided with a wood fiber layer having excellent smoothness, high mechanical strength, and small shrinkage and expansion due to moisture absorption / release, a decorative sheet can be easily attached and used as a flooring material. When used, it has the effect of withstanding a local load, and even when a veneer sheet is used as the decorative sheet, cracks in the veneer are less likely to occur due to the effects of contraction and expansion.

The moisture-proof sheet attached to the back surface of the substrate has a three-layer structure in which a polyethylene sheet is used as a core and kraft paper is laminated and integrated on the front and back sides. In addition to the waterproof effect of the polyethylene sheet of the core layer, Thus, the kraft paper on the front and back surfaces exhibits good adhesive strength to the back and substrate surfaces of the substrate.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a flooring material according to an embodiment of the present invention.

[Explanation of symbols]

 1 Substrate 2 Surface Wood Fiber Layer 3 Middle Wood Veneer Layer 4 Back Layer Wood Fiber Layer 5 Decorative Sheet 6 Kraft Paper 7 Polyethylene Sheet 8 Kraft Paper 9 Moisture-Proof Sheet 10 Male Fruit 11 Female Fruit

Claims (1)

[Claims] 1. A decorative sheet is attached to the surface of a substrate formed by laminating a surface wood fiber layer, a middle wood veneer layer and a back wood fiber layer in that order from the surface side, and a decorative sheet is attached to the surface of the substrate. A building board characterized in that a moisture-proof sheet having a polyethylene sheet as a core and kraft paper laminated on the front and back sides is attached to the back side.