JP2023102898A - Wooden composite material, floor material, method for manufacturing wooden composite material, and method for manufacturing floor material - Google Patents

Abstract

To provide a wooden composite material, a flooring material, and a method for manufacturing the same, capable of suppressing warping caused by dimensional change due to humidity change and the like, and sufficiently ensuring scratch resistance with excellent design.SOLUTION: A floor material 1 includes a wooden composite material 2 and a coating film 3. The wooden composite material 2 includes a wooden base material 10, a first wooden fiber board 11 bonded to the surface of the wooden base material 10, a second wooden fiber board 12 adhered to the surface of the first wooden fiber board 11, a decorative material 13 adhered to the surface of the second wooden fiber board 12, and grooves 14 formed in the decorative material 13 and the second wooden fiber board 12. The second wooden fiber board 12 is softwood MDF.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a wood composite material, a floor material, a method for manufacturing a wood composite material, and a method for manufacturing a floor material.

Flooring materials used in detached houses, condominiums and other buildings include solid flooring materials made of solid wood, surfaces of wooden base materials made of plywood, MDF, particle board, etc., or decorative flooring materials in which a decorative material of precious wood is attached to the surface of a wood base material obtained by laminating these wood base materials (hereinafter, the laminated wood base material is also simply referred to as "wood base material").

Decorative flooring uses a base material that expands and shrinks less due to moisture than solid wood, and various types of coatings are applied to the surface to prevent moisture from entering the interior.

A flooring material, which is a type of composite material, has a decorative board disposed on the surface (upper surface) side of a wooden base material, and grooves such as V-shaped grooves are formed in the decorative board to enhance design. In addition, the surface of the floor material is finished with a finish coating to ensure wear resistance, scratch resistance, smoothness, etc., and to prevent the fibers of the cleaning cloth from remaining in the grooves. The finish coating is performed using a colorless paint, a colored paint, or the like, and the surface of the floor material including the grooves is composed of a coating film.

In order to effectively use wooden substrates having defects in surface quality, such as softwood plywood and wooden substrates made from planted trees, composite materials in which wood fiber boards are combined with the surface of wooden substrates are used (see, for example, Patent Documents 1 to 4).

Patent No. 5909087 JP-A-2008-50896 Patent No. 5820994 specification Japanese Utility Model Laid-Open No. 6-16004

In the configuration described in Patent Document 1, the wood fiber board immediately below the surface decorative layer of the floor material is made of broadleaf wood fiber. Since the broad-leaved woody fiberboard has a dark color, when the surface decorative layer is light-colored, the broad-leafed woody fiberboard as a base becomes transparent through the surface decorative layer, and the color of the base becomes transparent. Such color see-through of the base impairs the pale color of the surface decorative layer, thereby degrading the design. However, if the broad-leaf wood fiberboard is simply replaced with the needle-leaf wood fiberboard, the dimensional change of the needle-leaf wood fiberboard due to changes in humidity becomes large. For this reason, the dimensional change of the floor material increases due to moisture from the concrete foundation and changes in humidity when the floor heating is used or not, resulting in large warp of the floor material.

In the configuration described in Patent Document 2, the decorative surface material is laminated on the wooden base material, and the groove is formed over the decorative surface material and the wooden base material. By coating the inner surface of the groove with a surface treatment agent containing a scale-like pigment, excessive absorption of the colored paint into the wooden substrate in the groove is suppressed. However, since the colored paint is prevented from permeating into the grooves, there is a possibility that paint pools may occur in the grooves. The paint pool in the groove deteriorates the design.

The wood board described in Patent Document 3 has a structure in which a wood thermoplastic resin sheet containing wood flour and an inorganic filler is adhered to the surface of a wood base, and a decorative layer is provided on the surface. A joint groove is formed in the decorative layer and the wood thermoplastic resin sheet, and the surface of the wood board including the joint groove is formed with a surface protective coating film. Also in this configuration, as in the configuration described in Patent Document 2, the colored paint is suppressed from permeating into the grooves, so there is a possibility that paint pools may occur in the grooves. The paint pool in the groove deteriorates the design.

The veneered decorative board described in Patent Document 4 has a configuration in which a veneer dyed in the same color as the thin veneer is interposed between a thin veneer arranged on the front side of the decorative board and a wooden substrate arranged on the back side of the decorative board. However, with this configuration, it is difficult to sufficiently ensure the strength of the single plate, and it is difficult to sufficiently ensure resistance to damage such as denting when a heavy object is dropped.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a wooden composite material, a flooring material, and a method for manufacturing the same, which can suppress warpage caused by dimensional changes due to changes in humidity, have excellent design properties, and can sufficiently ensure scratch resistance.

The gist of the present invention is the woody composite material, the flooring material, and the manufacturing method thereof as described below.

(1) a wooden substrate;
a first wood fiber board adhered to the surface of the wood substrate;
a second wood fiber board adhered to the surface of the first wood fiber board;
a decorative material adhered to the surface of the second wood fiber board;
grooves formed in the decorative material and the second wood fiber board;
with
The composite wood material, wherein the second wood fiber board is softwood MDF.

(2) The wood composite material according to (1), wherein the first wood fiber board is hardwood MDF.

(3) The wood composite material according to (2) above, wherein at least one of the softwood MDF density is 0.70 g/cm ³ or more and the hardwood MDF density is 0.70 g/cm ³ or more.

(4) The composite wood material according to any one of (1) to (3), wherein the second wood fiber board is thinner than the first wood fiber board.

(5) The wooden composite material according to any one of (1) to (4) above, wherein the decorative material is a light-colored board.

(6) The wood composite material according to any one of (1) to (5) above, wherein the wood base material includes a coniferous tree layer.

(7) The composite wood material according to any one of (1) to (6);
a coating film formed on the surface of the decorative material and the surface of the groove;
The floor coverings.

(8) a wooden substrate;
a first wood fiber board adhered to the surface of the wood substrate;
a second wood fiber board adhered to the surface of the first wood fiber board;
a decorative material adhered to the surface of the second wood fiber board;
grooves formed in the decorative material and the second wood fiber board;
with
A method for producing a composite wood material, wherein the second wood fiber board is soft MDF,
A method for producing a wood composite material, comprising separately preparing the wood base material, the first wood fiber board, the second wood fiber board, and the decorative material, and then stacking the wood base material, the first wood fiber board, the second wood fiber board, and the decorative material.

(9) forming a plurality of first divided plates by dividing the first raw material wood fiber board along the plate surface direction at a plurality of positions in the thickness direction of the first raw material wood fiber board;
The method for producing a wood composite material according to (8) above, wherein any one of the plurality of first split plates is the first wood fiber board.

(10) forming a plurality of second divided plates by dividing the second raw material wood fiber board along the board surface direction at a plurality of positions in the thickness direction of the second raw material wood fiber board;
The method for producing a wood composite material according to (8) or (9) above, wherein any one of the plurality of second split plates is the second wood fiber board.

(11) The method for producing a wood composite material according to (10), wherein the split plate to be the wood fiber board includes a bedrock layer having a relatively high density in the material wood fiber board.

(12) The method for producing a composite wood material according to (11), wherein the split plate to be the wood fiber board is arranged with the bedrock layer facing the decorative material.

(13) forming grooves in the facing material and the second wood fiber board of the wood composite material according to any one of (8) to (12);
a painting step of painting the wooden composite material in which the groove is formed;
A method of manufacturing a flooring material, comprising:

According to the present invention, it is possible to provide a composite wood material that can suppress warping due to dimensional changes due to changes in humidity, has excellent design properties, and can sufficiently ensure scratch resistance.

FIG. 1(A) is a cross-sectional view of a flooring material containing a wooden composite material according to the present embodiment, and shows a state cut along a cross section perpendicular to the length direction of the flooring material. FIG. 1(B) is an enlarged view of a part of FIG. 1(A). FIGS. 2(A) and 2(B) are schematic diagrams respectively showing the main part of the step of preparing the first wood fiber board and the second wood fiber board in the (A1) preparation step. FIG. 3 is a schematic diagram showing the (A2) bonding step. FIG. 4A is a schematic diagram showing the (A3) groove forming step, and FIG. 4B is a schematic diagram showing the (A4) painting step.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1(A) is a cross-sectional view of a flooring material 1 including a wooden composite material 2 according to the present embodiment, showing a state in which the flooring material 1 is cut along a cross section orthogonal to the longitudinal direction. FIG. 1(B) is an enlarged view of a part of FIG. 1(A). FIGS. 2(A) and 2(B) are schematic diagrams respectively showing the main part of the step of preparing the first wood fiber board and the second wood fiber board in the (A1) preparation step. FIG. 3 is a schematic diagram showing the (A2) bonding step. FIG. 4A is a schematic diagram showing the (A3) groove forming step. FIG. 4B is a schematic diagram showing the (A4) coating step.

1. Wood Composite Material According to the Present Embodiment Referring to FIGS. 1(A) and 1(B), the flooring 1 according to the present embodiment has a total thickness of about 12.0 mm. The width and length of the floor material 1 are not particularly limited. Widths are typically 150, 300, 303 mm and lengths 900, 1800, 1818 mm. The thickness is preferably thin from the viewpoint of workability (for reasons such as ease of cutting and less waste material), but from the viewpoint of rigidity, it is preferably 5.0 mm or more, more preferably 6.0 mm or more. The floor material 1 is installed on a base plate material, a hot water mat for floor heating, or the like. Hereinafter, when the flooring 1 is installed in a building, the surface of the flooring 1 facing the member on which the flooring 1 is placed is referred to as the back surface, and the surface facing the ceiling of the building is referred to as the front surface.

The floor material 1 has a wooden composite material 2 and a coating film 3.

The wood composite material 2 includes a wood base material 10, a first wood fiber board 11 bonded to the surface of the wood base material 10, a second wood fiber board 12 bonded to the surface of the first wood fiber board 11, a decorative material 13 bonded to the surface of the second wood fiber board 12, and grooves 14 formed in the decorative material 13 and the second wood fiber board 12.

The structure of the wooden base material 10 is not particularly specified. Examples of the wooden base material 10 include plywood, LVL (laminated veneer lumber), particle board, OSB (oriented strand board), and the like. The material of the wood base material is not particularly limited, but examples thereof include softwood plywood, fast-growing plywood such as planted trees, broad-leaved plywood, and plywood obtained by combining a plurality of such woods.

Examples of the softwood plywood include larch, Sakhalin fir, cypress, cedar, Ezo spruce, Japanese red pine, Douglas fir, hemlock, spruce, and radiata pine, as well as one or more selected from these. Examples of fast-growing plywood such as planted trees include falcata, eucalyptus, acacia manguum, japon, samama, and poplar, and one or more selected from these. Examples of hardwood plywood include South Sea wood such as Meranti, and fast-growing plywood such as lauan plywood and falcata plywood.

In this embodiment, the wooden base material 10 is a laminated board obtained by laminating a plurality of veneers, for example, a 5-ply plywood of coniferous trees. For example, the first, third and fifth layers are made of Sakhalin fir, and the second and fourth layers are made of Japanese cedar. In particular, for the first layer and the fifth layer (backing board), it is preferable to select a tree species having a relatively higher specific gravity than the second layer and the fourth layer (the core board). This is because tree species with a higher specific gravity tend to have higher strength and superior surface properties, while tree species with a lower specific gravity tend to have lower strength and more defects such as knots. Alternatively, the laminate may be a plywood in which the first, third and fifth layers are made of meranti boards and the second and fourth layers are made of falcata boards. The tree species may be appropriately selected depending on the performance required for the base material.

The thickness of each of the first layer, the third layer, and the fifth layer can be exemplified by 1.0 mm or more, 1.2 mm or more, 1.4 mm or more, 1.6 mm or more, or 1.7 mm or more. Further, the thickness of each of the second layer and the fourth layer can be exemplified by 2.0 mm or more, 2.2 mm or more, 2.4 mm or more, and 2.6 mm or more. Moreover, the second layer and the fourth layer are preferably made of the same tree species and have the same thickness. The thickness of each layer may be appropriately selected depending on the performance required for the substrate.

Note that the number of plies of the laminated plate constituting the wooden base material 10 may be 3, 7, or more than 7. The laminate may also be plywood with mixed wood species to meet the required performance.

The thickness of the wooden base material 10 is not particularly limited, but can be, for example, 8.0 to 12.0 mm, preferably 9.0 mm or more, for example, about 10 mm, from the viewpoint of ensuring sufficient strength. The bending Young's modulus in the width direction of the wooden substrate 10 is preferably 3.0 GPa or more.

In addition, a back material may be attached to the back surface of the wooden base material 10 . Examples of the backing material include sliced veneer, paper, resin film, resin-laminated paper, and polysand paper in which paper is compounded on both sides of resin. From the viewpoint of suppressing entry of water vapor into the flooring material 1, the backing material preferably has a water vapor transmission rate of 5 g/(m ² d) or less, more preferably 4 g/(m ² d) or less, as measured by JIS K 7129B (infrared sensor). When the backing material is veneer, the thickness is preferably 0.1 mm to 0.4 mm. Also, when the backing material is paper or film, the thickness is preferably 5 μm to 100 μm.

The first wood fiber board 11 is not particularly limited as long as it is a wood fiber board. Examples of the first wood fiber board 11 include MDF (Medium density fiberboard), HB (Hard Board), and insulation board. Examples of MDF include coniferous MDF and broadleaf MDF. Examples of these coniferous trees and broadleaf trees include the tree species described above. It is preferable that the first wood fiber board 11 is made of hardwood MDF, which has excellent hardness and small dimensional change due to changes in humidity. The density of hardwood MDF is preferably 0.70 g/cm ³ or more from the viewpoint of ensuring sufficient scratch resistance when a heavy object is dropped.

Hardwood MDF is dark-colored MDF made mainly of hardwood. It is preferable that the thickness of the hardwood MDF constituting the first wood fiber board 11 is 0.7 mm to 2.7 mm. By setting the thickness of the hardwood MDF to 0.7 mm or more, the strength (hardness) of the hardwood MDF can be sufficiently secured. As a result, the hardwood MDF can satisfactorily absorb the unevenness of the wooden base material 10 , and the lifting of the unevenness of the wooden base material 10 to the decorative material 13 can be suppressed more reliably. Further, by setting the thickness of the hardwood MDF to 2.7 mm or less, the dimensional change of the first wood fiber board 11 with respect to humidity does not become too large, and the warping of the floor material 1 can be suppressed more reliably. In addition, 0.7 mm, 1.0 mm, and 1.1 mm can be exemplified as the lower limit of the thickness of the hardwood MDF. Moreover, 2.7 mm, 2.2 mm, 1.7 mm, 1.5 mm, 1.4 mm, and 1.3 mm can be exemplified as the upper limit of the thickness of the hardwood MDF.

1(B) and 2(B), the first wood fiber board 11 is obtained, for example, by dividing a first raw material wood fiber board 21 (MDF), which is the material of the first wood fiber board 11, into two in the thickness direction using a slicer or the like, and grinding one of the two first split plates 31 to a predetermined thickness with a sander or the like. By dividing the MDF into the first wood fiber board 11, the thickness of the MDF (the first raw material wood fiber board 21) does not have to be formed to match the thickness of the first wood fiber board 11.例文帳に追加Further, by performing polishing, variations in the thickness of the plate surface can be reduced. From the viewpoint of ensuring the strength of the first wood fiber board 11, it is preferable that the first dividing plate 31 employed as the first wood fiber board 11 be either of the front and back surfaces of the MDF of the first raw material wood fiber board 21, which includes bedrock layers with high density on the front and back sides. In addition, the first dividing plate 31 employed as the first wood fiber board 11 is preferably arranged so that the cut surface of the first raw material wood fiber board 21 faces the wooden substrate 10 side (the bedrock layer is arranged facing the decorative material 13 side). As a result, the impact received from the side of the decorative material 13 can be received by the high-strength bedrock layer, and the scratch resistance, which is the resistance to denting of the floor material 1, can be further enhanced. The number of divisions of the first material wood fiber board 21 when molding the first wood fiber board 11 may be more than two. Alternatively, the first raw material wood fiber board 21 may be used as the first wood fiber board 11 as it is without being divided. The thickness of the first material wood fiber board 21 is not limited.

The second wood fiber board 12 is made of coniferous MDF. Examples of the conifers include the tree species described above. The density of softwood MDF is preferably 0.70 g/cm ³ or more, more preferably 0.80 g/cm ³ or more, and still more preferably 0.85 g/cm ³ or more, from the viewpoint of ensuring sufficient scratch resistance when a heavy object is dropped. The surface density of the portion of the second wood fiber board 12 where the grooves 14 are processed affects the ability to absorb the paint. If the density is too high, the suction of the paint becomes poor, and there is a risk that the grooves 14 will be filled with the paint. From the viewpoint of paint absorbency, the surface density of softwood MDF is preferably 1.1 g/cm ³ or less.

In this specification, both softwood MDF and hardwood MDF include high-density MDF having a density of 0.85 g/cm ³ or more.

Softwood MDF is a light-colored MDF made mainly of softwood. The thickness of the coniferous MDF forming the second wood fiber board 12 is preferably 0.3 mm to 1.0 mm. By setting the thickness of the coniferous MDF to 0.3 mm or more, it is possible to ensure resistance to damage such as dent damage when a heavy object is dropped. Also, by setting the thickness of the soft tree MDF to 1.0 mm or less, the dimensional change of the second wood fiber board 12 due to humidity change does not become too large, and warping of the floor material 1 can be suppressed more reliably. Further, although the wood fiber board is more easily soaked with the paint than the decorative material such as the veneer, by setting the thickness of the coniferous MDF to 1.0 mm or less, the problem that the paint penetrates too much in the groove part 14 and the coating film 3 is not formed on the surface of the second wood fiber board 12 can be suppressed. Therefore, the coating film 3 can be formed more uniformly on the surface of the second wood fiber board 12 and the surface of the decorative material 13 in the groove 14 . In addition, 0.3 mm and 0.4 mm can be exemplified as the lower limit of the thickness of the softwood MDF. Moreover, 1.0 mm, 0.7 mm, and 0.6 mm can be illustrated as an upper limit of the thickness of softwood MDF.

1(B) and 2(A), the second wood fiber board 12 is obtained by, for example, dividing the second material wood fiber board 22 (MDF), which is the material of the second wood fiber board 12, into four in the thickness direction using a slicer or the like, and grinding any one of the four second divided plates 32 to a predetermined thickness with a sander or the like. By dividing the MDF into the second wood fiber board 12, the thickness of the MDF (the second material wood fiber board 22) as a raw material does not have to be molded to match the thickness of the second wood fiber board 12.例文帳に追加By performing polishing, variations in the thickness of the plate surface can be reduced. From the viewpoint of ensuring the strength of the second wood fiber board 12, the second dividing plate 32 employed as the second wood fiber board 12 is preferably either the front or back surface of the coniferous MDF of the second raw material wood fiber board 22, which includes bedrock layers with high density on the front and back sides. In addition, the second dividing plate 32 employed as the second wood fiber board 12 is preferably arranged with the cut surface of the second raw material wood fiber board 22 facing the wooden substrate 10 (the bedrock layer is arranged facing the decorative material 13). As a result, the impact received from the side of the decorative material 13 can be received by the high-strength bedrock layer, and the scratch resistance, which is the resistance to denting of the floor material 1, can be further enhanced. The number of divisions of the second material wood fiber board 22 when molding the second wood fiber board 12 may be two, three, or more than four. The thickness of the second material wood fiber board 22 is not limited.

In this embodiment, the second wood fiber board 12 is made thinner than the first wood fiber board 11 . Thereby, the thickness of the second wood fiber board 12 can be prevented from becoming excessively large. As a result, the paint used when forming the coating film 3 can be prevented from soaking excessively into the second wood fiber board 12 in the groove part 14, and the finish (appearance) of the coating film 3 can be made more uniform between the groove part 14 and the decorative material 13.例文帳に追加In addition, it is possible to reduce the dimensional change in the second wood fiber board 12 made of MDF including coniferous trees, which undergoes greater dimensional changes with humidity changes than broad-leaved trees. Therefore, warping of the floor material 1 can be suppressed more reliably.

The total thickness (total thickness) of the first wood fiber board 11 and the second wood fiber board 12 is preferably 1.0 mm to 3.0 mm. By setting the total thickness of the wood fiber boards 11 and 12 to 1.0 mm or more, the strength of the wood fiber boards 11 and 12 can be sufficiently secured. Thereby, the unevenness of the wooden base material 10 can be satisfactorily absorbed by the wooden fiber boards 11 and 12, especially the first woody fiber board 11, and the lifting of the unevenness of the wooden base material 10 to the decorative material 13 can be suppressed more reliably. Further, by setting the total thickness of the wood fiber boards 11 and 12 to 3.0 mm or less, the dimensional change of the wood fiber boards 11 and 12, especially the dimensional change of the second wood fiber board 12 due to humidity does not become too large, and the occurrence of warping of the floor material 1 can be suppressed more surely. In addition, 1.0 mm, 1.2 mm, 1.5 mm, and 1.6 mm can be exemplified as the lower limit of the total thickness of the wood fiber boards 11 and 12 . Also, the upper limits of the total thickness of the wood fiber boards 11 and 12 can be exemplified by 3.0 mm, 2.5 mm, 2.2 mm, 1.9 mm, and 1.8 mm.

The decorative material 13 may be a processed wood such as veneer or sawn board, a resin film, a decorative sheet obtained by printing a color pattern on a sheet such as paper, or the like. The thickness of the decorative material 13 is generally 0.05 mm to 3.0 mm, but is not limited to this thickness. When the wooden decorative material 13 is attached by hot pressing (hot press), the thickness of the decorative material 13 is preferably 1.0 mm or less in order to sufficiently heat the adhesive bonding the decorative material 13 and the second wood fiber board 12 to increase the adhesive strength. In the present embodiment, the decorative material 13 is preferably composed of one light-colored plate. Examples of tree species for the light-colored board include maple, paulownia, camphor, chestnut, Japanese oak, birch, Japanese sen, tamo, Japanese horse chestnut, oak, elm, beach, sycamore, and cherry. The tree species of the light-colored board is not limited to the above tree species. In this way, by forming the decorative material 13 from a single light-colored board, the color difference between the light-colored second wood fiber board 12 made of coniferous MDF and the decorative material 13 can be reduced. Therefore, the device for reducing the color difference between the decorative material 13 and the second wood fiber board 12 in the groove 14 by the coating film 3 can be small, or the device can be made unnecessary. Furthermore, even if the decorative material 13 is thin, the deterioration of the design due to the reflection of the second wood fiber board 12 is small, so the degree of freedom in selecting the thickness of the decorative material 13 can be increased.

The adhesive for bonding the surface of the wood base material 10 and the back surface of the first wood fiber board 11, the adhesive for bonding the surface of the first wood fiber board 11 and the back surface of the second wood fiber board 12, and the adhesive for bonding the surface of the second wood fiber board 12 and the decorative material are not particularly limited. When the first wood fiber board 11 is hardwood MDF, a modified vinyl acetate adhesive can be exemplified as an adhesive for bonding the wood base 10 and the first wood fiber board 11 together, and a urea melamine resin adhesive can be exemplified as an adhesive for bonding the wood fiber boards 11 and 12 together. When the decorative material 13 is made of wood, a urea melamine resin adhesive can be exemplified as an adhesive for bonding the second wood fiber board 12 and the decorative material 13 together. On the other hand, when the decorative material 13 is a decorative sheet, the adhesive that bonds the second wood fiber board 12 and the decorative material 13 can be a water-based adhesive or a hot-melt adhesive. It is preferable that the location where the adhesive for bonding the wood fiber boards 11 and 12 is arranged is at least a location in the second wood fiber board 12 that is vertically opposed to the location where the groove 14 is formed, in order to prevent the paint for forming the coating film from soaking into the groove 14.

The groove portion 14 is formed along the length direction of the wooden composite material 2 . The groove 14 is formed in the decorative material 13 and the second wood fiber board 12, and is formed, for example, in a V shape in a cross section orthogonal to the longitudinal direction of the wood composite material 2. As shown in FIG. Note that the cross-sectional shape of the groove portion 14 is not particularly limited. The groove portion 14 may be configured by, for example, an R groove having a curved cross-sectional shape, a VR groove having a cross-sectional shape combining a straight surface and a curved surface, or the like. Moreover, the groove part 14 should just be formed over the decorative material 13 and the 2nd wood fiber board 12, and specific depth is not limited. However, the depth of the grooves 14 is preferably within the thickness range of the second wood fiber board 12 . This is because when the groove 14 reaches the first wood fiber board 11, the first wood fiber board 11 is exposed on the surface of the wood composite material 2, and the color of the groove bottom differs from that of the groove opening side in the groove 14, thereby degrading the design. Although the angle formed by the pair of side surfaces of the groove 14 is not particularly limited, it can be, for example, approximately 30 to 120 degrees.

In addition, in the figure, a mode in which the groove portion 14 is formed at an intermediate position in the width direction of the wooden composite material 2 is described as an example. However, this need not be the case. The grooves 14 may be half-grooves provided on the four sides of the outer circumference of the surface of the woody composite material 2 (portions that function as one groove by combining with adjacent products when constructed as a product), or may be chamfers. When the width of the wood composite material 2 is small, the groove 14 may not be formed along the length direction of the wood composite material 2 at the intermediate position in the width direction, and the groove 14 may be formed only on the outer circumference of the wood composite material 2.

Moreover, as the groove portion 14, a lateral groove formed along the width direction may be provided in addition to the longitudinal groove formed along the length direction. Further, in the case of the wooden composite material 2 having a herringbone-like design, the grooves 14 extend obliquely with respect to the length direction and the width direction. In this way, the orientation and location of the grooves 14 are appropriately set according to the design conditions of the wooden composite material 2, and are not limited to specific conditions.

The coating film 3 is formed on the surface of the decorative material 13 and the surfaces of the grooves 14 by applying a transparent paint, a translucent paint, or a colored paint to the surface of the woody composite material 2 and drying it. Water-based paints, solvent-based paints, and solvent-free paints can be exemplified as the above paints. The thickness of the coating film 3 is not particularly limited.

2. Method for Producing Flooring Material 1 According to the Present Embodiment Referring to FIGS. 1A to 4B, the flooring material 1 according to the present embodiment can be manufactured by the following steps.
(A1) a preparation step of individually preparing the wood base material 10, the first wood fiber board 11, the second wood fiber board 12, and the decorative material 13;
(A2) A bonding step of forming a composite material 40 by superimposing and bonding the wood base material 10, the first wood fiber board 11, the second wood fiber board 12, and the decorative material 13;
(A3) Groove forming step of forming grooves 14 in the decorative material 13 of the composite material 40 and the second wood fiber board 12 to form the wood composite material 2;
(A4) A coating step of forming the coating film 3 by coating the surfaces of the decorative material 13 and the grooves 14 in the wooden composite material 2 to use the wooden composite material 2 as the floor material 1 .
More specific description will be given below.

<(A1) Preparing Step of Individually Preparing Wood Base Material 10, First Wood Fiber Board 11, Second Wood Fiber Board 12, and Decorative Material 13>
The wood base material 10, the first wood fiber board 11, the second wood fiber board 12, and the decorative material 13 are each prepared in a single state from the materials described above.

Regarding the first wood fiber board 11, the first raw material wood fiber board 21 is divided along the board surface direction at a plurality of positions in the thickness direction of the first raw material wood fiber board 21 to form a plurality (for example, two) of the first divided boards 31, and one of the plurality of first divided boards 31 is used as the first wood fiber board 11. The first split plate 31 to be the first wood fiber board 11 is preferably ground to a predetermined thickness to become the first wood fiber board 11 . The first material wood fiber board 21 may be divided into three or more, but the first division board 31 to be the first material wood fiber board 11 preferably contains a bedrock layer with a relatively high density in the first material wood fiber board 21.

As for the second wood fiber board 12, the second raw material wood fiber board 22 is divided along the board surface direction at a plurality of positions in the thickness direction of the second raw material wood fiber board 22 to form a plurality (for example, four) of the second divided boards 32, and one of the plurality of second divided boards 32 is used as the second wood fiber board 12. The second split plate 32 to be the second wood fiber board 12 is preferably ground to a predetermined thickness to form the second wood fiber board 12 . The number (number of divisions) of the second split plates 32 formed from the second material wood fiber board 22 may be two or three, or may be more than four. Regarding the second dividing plate 32 to be the second wood fiber board 12, it is preferable in terms of manufacturing and cost to set the thickness when dividing from the second raw material wood fiber board 22 to a value close to the target final thickness and adjust it to the final thickness by grinding. Moreover, it is preferable that the second dividing plate 32 to be the second wood fiber board 12 includes a bedrock layer having a relatively high density in the second raw material wood fiber board 22 .

<(A2) Adhesion Step of Forming Composite Material 40 by Laminating and Adhering Wood Base Material 10, First Wood Fiber Board 11, Second Wood Fiber Board 12, and Decorative Material 13>
When molding the composite material 40, various patterns are conceivable as the order in which the wood base material 10, the first wood fiber board 11, the second wood fiber board 12, and the decorative material 13 are layered and adhered. For example, patterns 1 to 3 below can be exemplified. When the members are adhered to each other, an adhesion method such as adhesion processing by hot pressing or adhesion processing at room temperature is appropriately selected.

As a pattern 1, as shown in FIG. 3, a pattern in which a first wood fiber board 11 is adhered to a wood base material 10, a second wood fiber board 12 is adhered to the first wood fiber board 11, and then a decorative material 13 is adhered to form a composite material 40 can be exemplified.

As a pattern 2, as shown in FIG. 3, a composite material 40 is formed by bonding the wood fiber boards 11 and 12 together, then bonding the wood base material 10 to a composite fiber board formed by bonding the wood fiber boards 11 and 12 together, and then bonding the decorative material 13 to the second wood fiber board 12.

As a pattern 3, as shown in FIG. 3, the wood fiber boards 11 and 12 are adhered to each other, then the decorative material 13 is adhered to the composite fiber board formed by adhering the wood fiber boards 11 and 12 to each other, and then the wood base material 10 is adhered to the first wood fiber board 11 to form the composite material 40.

Since both the single second wood fiber board 12 and the single decorative material 13 are extremely thin, it is not practical to bond the single second wood fiber board 12 and the single decorative material 13, but such a bonding process is not excluded.

The adhesive for bonding the wood base material 10 and the first wood fiber board 11, the adhesive for bonding the wood fiber boards 11 and 12 together, and the adhesive for bonding the second wood fiber board 12 and the decorative material 13 can be exemplified by those described above.

As a more specific example of a method of superimposing and adhering the wood base material 10, the first wood fiber board 11, the second wood fiber board 12, and the decorative material 13, a modified vinyl acetate adhesive is applied to the wood base material 10, and the first wood fiber board 11 made of hardwood MDF is bonded together to form a composite base material by thermal pressure compounding. After laminating the second wood fiber board 12 made of MDF, temporary pressing is performed, a urea melamine resin adhesive is applied thereon, and the decorative material 13 is laminated to perform thermocompression compounding (simultaneous lamination).

As a more specific example of the method of superimposing and adhering the wood base material 10, the first wood fiber board 11, the second wood fiber board 12, and the decorative material 13, a case of using a decorative sheet as the decorative material 13 can be mentioned. In this case, a modified vinyl acetate adhesive is applied to the wood base material 10, and the first wood fiber board 11 made of hardwood MDF is bonded together to form a composite base material by hot-pressing. Next, a urea melamine resin adhesive is applied to the first wood fiber board 11 of the composite base material, and a second wood fiber board 12 made of coniferous MDF is bonded and hot-pressed. A method of sticking a decorative sheet with an agent or the like can be mentioned.

<(A3) Groove Forming Step of Forming Groove 14 in Composite Material 40 to Form Woody Composite Material 2>
In this step, as shown in FIG. 4A, grooves 14 are formed in the composite material 40 by applying groove forming processing to the decorative material 13 and the second wood fiber board 12 of the composite material 40 with a cutter or the like, and the wood composite material 2 is molded.

<(A4) Coating step of forming the coating film 3 by coating the surface of the decorative material 13 and the groove 14 in the wooden composite material 2, and using the wooden composite material 2 as the floor material 1>
In this step, as shown in FIG. 4B, the above-described paint is applied to the decorative material 13 and the grooves 14 of the wooden composite material 2 where the grooves 14 are formed, and dried to form the flooring material 1 with the coating film 3 formed on the surface of the woody composite material 2. The method of applying the coating material in the coating process is not particularly limited. Examples of coating methods include flow coater (curtain coater), roll coater, and spray coating. Among these coating methods, in the case of flow coater coating in which the coating is applied thickly, the suction of the coating in the grooves 14 greatly affects the design of the flooring 1 . In the roll coater and the spray coating, the suction of the coating material into the grooves 14 affects the design of the flooring 1 .

As described above, according to the present embodiment, the grooves 14 are formed in the decorative material 13 and the second wood fiber board 12, and the second wood fiber board 12 is soft MDF. The first wood fiber board 11 is adhered to the back surface of the second wood fiber board 12 . With this configuration, the thickness of the second wood fiber board 12 can be reduced. Therefore, the dimensional change of the second wood fiber board 12 in the wooden composite material 2, such as dimensional change due to moisture from the building side and dimensional change due to drying during floor heating, can be reduced. Further, when the decorative material 13 is composed of a light-colored board, both the decorative material 13 and the second wood fiber board 12 are light-colored. Therefore, the difference in color between the decorative material 13 and the second wood fiber board 12 can be reduced in the groove 14, and the color of the base (the second wood fiber board 12) does not show through. Further, it is possible to use a transparent paint instead of using a colored paint as a material for the coating film 3 formed on the surface of the wooden composite material 2.例文帳に追加Therefore, a natural finish with excellent design can be achieved. Moreover, since the adhesive layer is provided between the second wood fiber board 12 and the first wood fiber board 11, it is possible to prevent the paint from penetrating below the adhesive layer. Therefore, the paint is appropriately sucked into the thin second wood fiber board 12 in the grooves 14 . As a result, the paint is appropriately applied to the surfaces of the grooves 14, and the occurrence of paint puddles in the grooves 14 can be suppressed. As a result, it is possible to achieve a natural finish with even better design. Further, when the decorative material 13 is composed of a dark-colored board, a color difference occurs between the decorative material 13 and the light-colored second wood fiber board 12 in the groove part 14, so that a colored paint is required as a material of the coating film 3. - 特許庁However, as described above, the second wood fiber board 12 can be made moderately thin, and the adhesive layer is provided between the second wood fiber board 12 and the first wood fiber board 11, so that the paint can be prevented from permeating the first wood fiber board 11 below the adhesive layer. Therefore, the colored paint is appropriately absorbed into the second wood fiber board 12 in the grooves 14 . As a result, the paint is appropriately applied to the surface of the groove portion 14, and the coating film 3 can be reliably formed on the groove portion 14. - 特許庁Therefore, even when dirt occurs in the groove 14, the dirt adheres to the coating film 3, which facilitates manual wiping of the dirt. In addition, when the coating film 3 is not formed in the groove 14, moisture and wax may permeate the second wood fiber board 12 to cause swelling and mold, but the occurrence of such troubles can be suppressed. In addition, since the paint is appropriately applied to the grooves 14, it is possible to suppress the occurrence of paint puddles in the grooves 14. - 特許庁As a result, a natural color tone can be achieved over the decorative material 13 and the second wood fiber board 12 in the groove 14, and a natural finish with excellent design can be achieved. Moreover, since the second wood fiber board 12 is soaked with the paint to some extent, the adhesiveness between the coating film 3 and the wood composite material 2 can be enhanced, the peeling of the coating film 3 from the wood composite material 2 can be suppressed, and the deterioration of the design property can be suppressed. Furthermore, since the second wood fiber board 12 composed of MDF having a higher strength than a single board is arranged directly under the decorative material 13, it is possible to ensure scratch resistance such as difficulty of denting when a heavy object is dropped. Depending on the above, it is possible to realize the wooden composite material 2 that can suppress warpage due to dimensional changes due to humidity changes, etc., has excellent design properties, and can sufficiently ensure scratch resistance.

Further, according to this embodiment, when the first wood fiber board 11 is made of hardwood MDF, the first wood fiber board 11 can be formed of a material that undergoes less dimensional change with humidity changes than softwood. Therefore, warping of the wooden composite material 2 can be suppressed more reliably.

Further, according to the present embodiment, the second wood fiber board 12 is thinner than the first wood fiber board 11 , so that the paint, which is the material of the coating film 3 , is properly absorbed into the second wood fiber board 12 . In addition, since the dimensional change of the second wood fiber board 12 due to humidity changes is small, the warp of the floor material 1 can be reduced.

Further, according to the present embodiment, even when the decorative material 13 is a light-colored board, the second wood fiber board 12 made of coniferous MDF can be less transparent to the decorative material 13 . Therefore, even when the decorative material 13 is a light-colored board, the natural color of the floor material 1 can be realized, and the design of the floor material 1 can be enhanced.

Moreover, according to the present embodiment, when the wooden base material 10 includes a coniferous tree layer, it is possible to effectively utilize tree species such as Japanese cedar and Japanese cypress that are relatively widely planted in Japan as the flooring material 1 . In particular, when the wooden base material 10 includes a coniferous tree layer and a broadleaf tree layer, warping of the floor material 1 can be more reliably suppressed by the hardwood that undergoes little dimensional change due to changes in humidity.

In the above-described embodiment, an example of using the wooden composite material 2 as a floor material has been described. However, this need not be the case. The wood composite material 2 may be used for other uses such as wall materials.

In order to confirm the effects of the present invention, Example, Comparative Example 1, Comparative Example 2, and Comparative Example 3, which are floor materials, were produced.

<Production method of the example>
A modified vinyl acetate adhesive was applied to the surface of a wooden base made of softwood plywood, and a first wood fiber board made of broadleaf MDF was laminated and subjected to thermal pressure compounding to prepare a composite base. Next, a urea melamine resin adhesive was applied to the surface of the first wood fiber board in the composite base material, and a second wood fiber board made of coniferous MDF was pasted together. After that, temporary pressing was performed, and a urea melamine resin adhesive was applied thereon, and the decorative board was pasted together to perform thermocompression composite (simultaneous pasting) to produce a wood composite material. Next, grooves were formed in the decorative wood composite material and the second wood fiber board, and then paint was applied to the surface of the wood composite material by flow coater coating to complete the floor material.

<Method for creating Comparative Example 1>
A composite substrate was produced by applying a modified vinyl acetate adhesive to the surface of a wooden substrate made of softwood plywood, bonding wood fiber boards made of broadleaf MDF, and performing thermal pressure compounding. Next, a urea melamine resin adhesive was applied to the surface of the wood fiber board in the composite base material, and a decorative board was adhered to the wood composite material by hot-pressing. Next, grooves were formed in the decorative wood composite material and the wood fiber board, and then the paint was applied to the surface of the wood composite material by flow coater coating to complete the floor material.

<Method of creating Comparative Example 2>
A composite substrate was produced by applying a modified vinyl acetate adhesive to the surface of a wooden substrate made of a softwood plywood, bonding a wooden fiber board made of a softwood HB, and performing heat and pressure compounding. Next, a urea melamine resin adhesive was applied to the surface of the wood fiber board in the composite base material, and a decorative board was adhered to the wood composite material by hot-pressing. Next, grooves were formed in the decorative wood composite material and the wood fiber board, and then the paint was applied to the surface of the wood composite material by flow coater coating to complete the floor material.

<Production method of Comparative Example 3>
A flooring material was prepared in the same manner as in Comparative Example 1, except that soft tree MDF was used as the wood fiber board.

<Materials and thicknesses of Examples and Comparative Examples 1 to 3>
The configuration of the embodiment is as follows.
Wooden substrate: 10.0mm softwood plywood (with backer paper)
First wood fiber board: 1.2 mm hardwood MDF
Second wood fiber board: 0.47 mm softwood MDF
Decorative material: 0.3 mm veneer (maple)

The configuration of Comparative Example 1 is as follows.
Wood substrate: 9.0 mm softwood plywood Wood fiber board: 2.7 mm hardwood MDF
Decorative material: 0.3 mm veneer (maple)

The configuration of Comparative Example 2 is as follows.
Wooden substrate: 10.0mm softwood plywood (with backer paper)
Wood fiber board: 1.8 mm softwood HB
Decorative material: 0.3 mm veneer (maple)

The configuration of Comparative Example 3 is as follows.
Wood substrate: 9.0 mm softwood plywood Wood fiber board: 2.7 mm softwood MDF
Decorative material: 0.3 mm veneer (maple)

As is clear from the above description, two of the first and second wood fiber boards are provided in the example, whereas only one wood fiber board is provided in comparative examples 1 to 3. The dimensions of the example and comparative examples 1 to 3 are all 303 mm wide×1818 mm long.

<Test method>
Test 1 (drying test): The sample was left in a dry environment with a temperature of 40°C and a humidity of 30% for two weeks, and the dimensional change before and after the test was measured.
Test 2 (hygroscopic test): The sample was left in a hygroscopic environment with a temperature of 30°C and a humidity of 90% for two weeks, and the dimensional change before and after the test was measured.
In Tests 1 and 2, the design of the groove was visually evaluated.
The results are shown in Table 1

<Evaluation for dimensional change>
A dimensional change rate was evaluated. The dimensional change rate (%/%) is the dimensional change amount (%) obtained by dividing the dimensional change amount due to drying and moisture absorption of the wood by the size before the start of the test, divided by the amount of change (%) in the moisture content of the wood due to drying and moisture absorption. It is the amount of dimensional change per 1% moisture content. The moisture content was measured by the dry method of measuring the total dry weight of the product, and the dry moisture content was used for the calculation.

For example, if the original dimension is 1818 mm and it is 1816 mm after the drying test, the amount of change is 2 mm, and the amount of dimensional change is 2 mm/1818 mm=0.11 (%). For example, if the moisture content changes by 4% after the drying test, the dimensional change rate is 0.11(%)/4(%)=0.0275(%/%). If the dimensional change rate is large, the amount of dimensional change is large when the moisture content changes by 1%, and it can be said that warping and gaps are likely to occur (behavior is large).

In the drying test, the dimensional change rate of the examples was the smallest in both the length direction and the width direction, demonstrating that the degree of dimensional change due to drying was extremely small. In addition, in the moisture absorption test, although the dimensional change rate of the example was larger than that of Comparative Examples 1 and 3 in both the length direction and the width direction, the dimensional change rate of the example in the drying test was significantly smaller than that of the example, demonstrating that the degree of dimensional change due to moisture absorption was extremely small.

As is clear from Comparative Examples 2 and 3, when all the wood fiber boards are made of coniferous wood, even if the thickness is small (even if the ratio to plywood is small), the dimensional change is greater than that of hardwood, so warping increases when the humidity changes, especially when dry. In the example, it was demonstrated that dimensional change could be suppressed by reducing the thickness ratio of the soft wood MDF as the second wood fiber board, and that the behavior with respect to humidity change was small. Since dimensional change can be reduced particularly under dry conditions, warpage and gaps can be reduced when floor heating is used.

<Evaluation of designability>
For Examples and Comparative Examples 1 to 3, both electron microscope observation and visual observation with the naked eye were used. For observation with an electron microscope, a cross section orthogonal to the longitudinal direction was magnified 100 times with an electron microscope, and the magnified image was taken. Then, in the enlarged image, it was determined whether or not the coating film was formed on the decorative material and the entire surface of the groove, and it was determined whether or not there was a problem with the coating film in the groove due to the presence of paint pools at the bottom of the groove. Also in the visual observation with the naked eye, the same judgment as the judgment using the photographed image was performed.

The presence or absence of paint puddles was determined mainly by visual observation with the naked eye, and whether or not a coating film was formed on the entire surfaces of the decorative material and the grooves was determined mainly by images taken using an electron microscope.

Evaluation was carried out as follows.
◯: No problem with the design of the groove.
x: There is a portion where the coating film is not left in the groove.
XX: There is a portion where the paint pool is formed in the groove.
As long as a coating film is formed on the surface of the flooring material, there is no problem of staining or absorption of water and wax, so the presence or absence of the coating film was evaluated as ◯×.

In Comparative Examples 1 and 3, the grooves absorbed too much paint, and there were places where the paint film did not remain, so the evaluation was "x". In addition, in Comparative Example 2, since the surface density of HB was high, the paint was difficult to permeate, and as a result, there were places where the paint pooled in the grooves. Comparative Example 2 was visually observed as if the grooves were filled with paint. As in Comparative Example 2, when the wood fiber board is HB with a thickness of 1.8 mm and a surface density of 1.1 g/cm ³ , there is a possibility that paint pools may occur. On the other hand, in the example, the average surface density was 0.85 g/cm ³ (0.83 to 0.88 g/cm ³ ) as measured by polishing to a thickness of 0.3 to 0.4 mm so as to leave a relatively high-density bedrock layer of the wood fiber board. It can be said that even with MDF, which is also a wood fiber board, if the surface density is about 1.1 g/cm ³ , there is a possibility that paint pools may occur as with HB. Also, the HB of Comparative Example 2 uses a coniferous material, but the color is dark due to the manufacturing process. Therefore, groove coloring is necessary when using a light-colored board as a decorative material. On the other hand, in the example, a coating film having an appropriate thickness was formed over the entire groove, and there was no paint pool, and the coating film was formed in the groove in a V-shaped cross section. There was no problem with the design finish of the groove, and the evaluation was ◯, demonstrating that the design was excellent.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a woody composite material, a flooring material, and a method for manufacturing these.

1 Floor material 2 Woody composite material 3 Coating film 10 Woody base material 11 First woody fiber board 12 Second woody fiberboard 13 Decorative material 14 Groove 21 First material woody fiberboard 22 Second material woody fiberboard 31 First dividing board 32 Second dividing board

Claims (13)

a wooden substrate;
a first wood fiber board adhered to the surface of the wood substrate;
a second wood fiber board adhered to the surface of the first wood fiber board;
a decorative material adhered to the surface of the second wood fiber board;
grooves formed in the decorative material and the second wood fiber board;
with
The composite wood material, wherein the second wood fiber board is softwood MDF. The wood composite according to claim 1, wherein said first wood fiber board is hardwood MDF. 3. The composite wood material according to claim 2, wherein at least one of density of the softwood MDF is 0.70 g/ ^cm3 or more and density of the hardwood MDF is 0.70 g/ ^cm3 or more. The composite wood material according to any one of claims 1 to 3, wherein the second wood fiber board is thinner than the first wood fiber board. The composite wood material according to any one of claims 1 to 4, wherein the decorative material is a light-colored board. The wood composite material according to any one of claims 1 to 5, wherein the wood base material includes a softwood layer. The composite wood material according to any one of claims 1 to 6;
a coating film formed on the surface of the decorative material and the surface of the groove;
The floor coverings. a wooden substrate;
a first wood fiber board adhered to the surface of the wood substrate;
a second wood fiber board adhered to the surface of the first wood fiber board;
a decorative material adhered to the surface of the second wood fiber board;
grooves formed in the decorative material and the second wood fiber board;
with
A method for producing a composite wood material, wherein the second wood fiber board is soft MDF,
A method for producing a wood composite material, comprising separately preparing the wood base material, the first wood fiber board, the second wood fiber board, and the decorative material, and then stacking the wood base material, the first wood fiber board, the second wood fiber board, and the decorative material. forming a plurality of first divided plates by dividing the first raw material wood fiber board along the board surface direction at a plurality of positions in the thickness direction of the first raw material wood fiber board;
9. The method of manufacturing a composite wood material according to claim 8, wherein any one of the plurality of first split plates is the first wood fiber board. forming a plurality of second divided plates by dividing the second raw material wood fiber board along the board surface direction at a plurality of positions in the thickness direction of the second raw material wood fiber board;
10. The method of manufacturing a composite wood material according to claim 8, wherein one of the plurality of second split plates is the second wood fiber board. 11. The method for producing a wood composite material according to claim 10, wherein said split plate to be said wood fiber board includes a bedrock layer having a relatively high density in said material wood fiber board. 12. The method of manufacturing a woody composite material according to claim 11, wherein said split plate to be said woody fiber board is arranged with said bedrock layer facing said decorative material. a step of forming grooves in the facing material and the second wood fiber board of the wood composite according to any one of claims 8 to 12;
a painting step of painting the wooden composite material in which the groove is formed;
A method of manufacturing a flooring material, comprising:

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