JP2000291242A - Wooden floor material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve flexibility, floor matching and sound insulation while securing sufficient strength by forming a rear groove on the rear face of a base material in parallel, and forming a notch on the bottom part of the rear groove in the substantially seam direction as the rear groove. SOLUTION: In a wooden floor material on which a decorative material 2 is provided on the surface of a base material 1, a plurality of rear grooves 5, 5 are formed on the rear face of the base material 1 in parallel, and notches 10, 10 are formed on the bottom part of the rear groove 5 in the substantially the same direction of the rear groove. The base material 1 is preferably constituted of a plywood laminated by mutually intersecting a plurality of veneers 1a-1a at right angles in the direction of the fiber. In addition, a lining material 4 comprising a buffer material and/or a soft material is laminated on the rear face side of the base material 1. Thus, cutting sound and a cutting layer can be reduced during groove processing, and flexibility, floor matching and sound insulation can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wooden flooring material laid on a floor base such as a wooden board or concrete.

[0002]

2. Description of the Related Art As a wooden flooring material to be laid on a flat floor foundation such as a wooden flooring or concrete, a wooden flooring having a decorative material such as a decorative veneer provided on a base material such as plywood is well known.

Conventionally, in such a wooden flooring material, for example, Japanese Patent Application Laid-Open Nos. Hei 6-158832 and Hei 3-166462.
As shown in No. 4-113640, a number of back grooves are formed on the back side of the base material to give flexibility, thereby improving adaptability to a floor base, and using a nail. Laying construction using only adhesive without the need to prevent the propagation of impact sound when impact is applied to the floor material,
Techniques for improving sound insulation have been developed.

[0004]

However, in the above-mentioned conventional wood flooring with a back groove, the flexibility and sound insulation are improved as the depth of the back groove is increased, but the back groove has a circular shape. Since the cutting is performed by a saw or the like, the cutting noise during cutting the groove and the amount of cutting chips increase, and the abrasion of the circular saw increases. Moreover, when the depth of the back groove becomes deep, the strength of the floor material itself decreases, and for example, at the time of manufacture or construction, the floor material is turned upside down, When the floor material is gripped and lifted, the floor material may be greatly bent in a mountain shape or may be bent in some cases, and there is a problem that handling is difficult.

The present invention solves the above-mentioned problems of the prior art, and can reduce the generation of cutting noise and cutting chips at the time of grooving, and reduce the wear of a grooving circular saw and the like, and secure sufficient strength. It is an object of the present invention to provide a wooden flooring material which can be prevented from being largely bent at the time of lifting or the like, and which can improve flexibility, floor adaptability, and sound insulation.

[0006]

As a result of the inventor's diligent efforts, the sound insulation of the wooden flooring material is such that the softness of the flooring material is more concave than the convex deformation property in which the flooring material surface becomes convex. It has been found that the sound insulation is improved if the concave deformability is large regardless of the convex deformability. Furthermore, as a result of repeated detailed experiments, the present inventor has found an optimal configuration that can achieve the above object as a wooden flooring material, and has accomplished the present invention.

That is, according to the present invention, in a wooden flooring material in which a decorative material is provided on the surface of a base material, a plurality of back grooves are formed in parallel on the back surface of the base material, and The gist of the present invention is to form a notch in substantially the same direction as the back groove.

In the wooden flooring material of the present invention, the cut is formed at the bottom of the back groove, so that the concave deformation of the floor material surface becomes concave without forming the back groove deeper than necessary. Can be secured. Therefore, for example, even if an impact is applied to the floor material surface, the concave deformation can effectively prevent the propagation of the impact sound and improve the sound insulation.

In the present invention, the sound insulation refers to light floor impact sound insulation performance.

Further, since the back groove does not have to be formed deeper than necessary, sufficient strength can be ensured.
The convex deformability in which the floor material surface becomes convex can be appropriately suppressed. Therefore, it is possible to prevent the floor material from being largely bent or bent in a mountain shape when the floor material is lifted up with the intermediate portion or the end portion with the surface thereof facing upward during manufacturing or construction of the floor material. In addition, floor materials can be easily handled.

Further, in the wooden flooring material of the present invention, since it is not necessary to form the back groove deeply, cutting dust and cutting noise can be reduced when the back groove is machined by a circular saw or the like, and the circular saw is worn. Can be reduced.

The back groove can secure a predetermined convex deformability, and the back groove and the notch can secure a sufficient concave deformability, so that sufficient flexibility can be obtained and adaptability to the floor substrate can be improved. It can be good. For this reason, even if there is unevenness in the floor substrate, the floor substrate can be easily adapted to the floor substrate and can be constructed with only the adhesive without using nails. That is, it is possible to bond the floor base and the lower surface of the floor material, bond the joint surfaces of the floor materials, or to lay and use them together.

On the other hand, in the present invention, it is preferable to adopt a configuration in which the base material is constituted by a plywood in which a plurality of veneers are laminated with their fiber directions alternately orthogonal to each other.

That is, when this configuration is adopted, the occurrence of cracks can be reduced or prevented when cutting with a cutting blade for forming a cut, so that the cut amount of the cut can be accurately determined. Can be controlled.

Further, in the present invention, it is preferable to adopt a configuration in which a backing material made of a cushioning material and / or a soft material is laminated on the back surface side of the base material.

That is, when this configuration is adopted, the adaptability to the floor substrate and the sound insulation can be further improved.

Further, in the present invention, it is preferable to adopt a configuration in which the back groove is formed at a depth of at least half the thickness of the base material.

That is, when this configuration is adopted, an appropriate convex deformability can be provided.

In the present invention, it is more preferable to adopt a configuration in which the length direction of the cut is set substantially in the same direction as the width direction of the base material.

That is, when this configuration is adopted, flexibility can be imparted in the length direction of the floor material.

Further, in the present invention, it is more desirable to adopt a configuration in which the tip of the cut is located on the second single layer from the top of the base material.

That is, when this configuration is employed, the concave deformability can be further improved while imparting appropriate convex deformability.

Further, in the present invention, it is even more preferable to adopt a configuration in which the length direction of the cut is set substantially in the same direction as the fiber direction of the second layer veneer.

That is, when this configuration is employed, the concave deformability can be further improved while imparting appropriate convex deformability.

Hereinafter, the structure of the wooden flooring material of the present invention will be described in more detail with reference to the drawings.

As shown in FIGS. 1 and 2, the wooden flooring material of the present invention is intended for a decorative material (2) provided on the surface side of a substrate (1). Further, on the back surface of the base material (1), a number of back grooves (5) extending in the floor material width direction are provided in parallel, and a cut (10) is formed at the bottom of each back groove (5). .

In the present invention, as the base material (1), wood fiber board such as medium fiber board (MDF), hard fiber board (HB), high specific gravity fiber board (HDF), plywood, particle board, etc. A plate and a combination thereof can be suitably used. Above all, as shown in FIG. 3, a plurality of veneers (1a) to (1e) are used as the base material (1).
Made of plywood laminated with their fiber directions alternately orthogonal to each other can be more preferably used. That is, when making a cut (10) in the base material (1), a so-called tip crack may occur, in which the tip of the cutting blade acts as a wedge to cause a crack in front of the cutting edge. When this crack occurs, not only is it difficult to adjust the cutting depth, but also the cutting depth becomes deep, which may adversely affect the strength of the base material (1). Therefore, when the plywood as described above is used as the base material (1), it is possible to avoid an adverse effect due to the crack. In other words, at the time of cutting, if the cutting blade is orthogonal to the fiber direction of the veneer on which the cutting edge is located, the wood fiber of the veneer will not be cracked just by being cut, The depth of cut can be accurately controlled. Further, as shown in FIG. 3, when the cutting blade is parallel to the fiber direction of the veneer (1b) on which the cutting edge is located, a crack occurs in the veneer (1b) on which the cutting edge is located. The veneer (1a) located above the veneer (1b) on which the cutting edge is located has a fiber direction orthogonal to the cutting blade, so that no cracking occurs and the veneer on which the cutting edge is located. Pre-cracking stops in the layer of (1b). Therefore, the cuts (10) are not formed unnecessarily deep due to the cracks, and a decrease in the strength of the substrate (1) can be reliably prevented.

As the substrate (1), as shown in FIG. 1, a long plate having a rectangular shape or the like in plan view is preferably used.

In the present invention, as the decorative material (2),
Known materials such as a wooden veneer, a decorative resin sheet, decorative printing paper and the like can be suitably used, and of course, those formed by painting or pattern printing can also be used.

In particular, as shown in FIG. 3, when a plywood is used as the base material (1), a decorative material (2) made of a wooden veneer is preferably used. That is, the fiber direction of the decorative material (2) is the top layer veneer of the plywood (front veneer 1a)
When it is parallel to the fiber direction, even if a load that causes concave deformation is applied to the floor material, the occurrence of cracks in the decorative material (2) at the upper part of the back groove (5) can be suppressed.

Furthermore, when the fiber direction of the decorative material (2) is orthogonal to the fiber direction of the veneer front veneer (1a) as the base material (1), cracking of the decorative material (1) is prevented. be able to.

In the present invention, as shown in FIG. 3, an intervening layer (3) is provided between the base material (1) and the decorative material (2) in order to prevent the decorative material (2) from cracking. It is better to intervene.

As the intervening layer (3), those composed of sheets such as paper, nonwoven fabric, resin sheet, and resin-impregnated sheet can be suitably used. Further, when these sheets are used as the intervening layer (3) and plywood is used as the base material (1), the sheet having the larger tensile strength is used as the front veneer (1a) of the base material (1). It is preferable to arrange them so as to be orthogonal to the fiber direction of (2).

The sheets used as the intervening layer (3) are usually made of a plywood front veneer (1) as the base material (1).
Since the thickness is smaller than a), the flexibility of the floor material itself is not impaired.

As shown in FIGS. 1 and 2, in the present invention, the method of forming the back groove (5) is not particularly limited, but it may be formed by cutting using a circular saw, for example. it can.

By forming the back groove (5) in this way, the flooring material itself can be imparted with flexibility, unevenness deformability, particularly convexity deformation, and also has an effect of suppressing warpage of the flooring material. Can be imparted, and the sound insulation can be further improved.

The back groove (5) has a groove width (W) of 1.0 to 1.0.
It is preferably set to 3.0 mm, and the groove interval (P) is set to 1
Preferably, it is set to 0 to 30 mm. That is, if the value is outside this range, it may be difficult to sufficiently obtain the effect of the groove formation such as the flexibility described above.

The depth (D) of the back groove (5) is preferably set to be at least half the thickness of the base material (1) in order to impart flexible convexity to the floor material. .

Since the back groove (5) is affected by the cut (10) described later in detail, the size and size of the above-described back groove (5) are determined by the size of the cut (10). It is preferable to appropriately adjust according to the dimensions and the like.

As shown in FIG. 1, the floor material may have surface grooves (20) and (21) formed on the surface thereof in the width direction and the length direction. Groove (20)
It is better not to form the back groove (5) at the portion corresponding to the above, that is, at the portion corresponding to the front groove (20) parallel to the back groove (5). Specifically, on the back surface of the flooring material corresponding to the front groove (20), the interval between the adjacent back grooves (5) is set to be about three times or more the thickness of the base material (1), and Preferably, the front groove (20) is located in the middle of the matching back groove (5). That is, by not forming the back groove (5) at the position corresponding to the front groove (20) or in the vicinity thereof, it is possible to sufficiently secure the strength of the floor material around the front groove (20). When a load is applied to the periphery of the front groove (20) from the front surface side, it is possible to prevent bending around the periphery.

In the position corresponding to the front groove (20), even if the back groove (5) is not formed, the front groove (20) is not formed.
, The effect of grooving such as flexibility can be sufficiently obtained.

In the present invention, the back groove (5) may be formed not only in the width direction of the flooring material but also in the length direction as shown in FIG. The back groove may be as deep as the back groove in the width direction or shallow.

In the present invention, at the bottom of the back groove (5),
A cut (10) is formed from the bottom surface toward the floor material surface side. Each cut (10) is formed so that its length direction is substantially the same as the length direction of the back groove (5).

The cut (10) does not necessarily need to be formed at the center position of the back groove (5), but may be formed at any position with respect to the groove bottom.

The means for forming the cut (10) is not particularly limited. For example, a method of forming the cut using a disk-shaped knife, a cutter, a scribing knife, or the like, or embedding a press-cutting blade in the base. And a method in which the blade is formed by pressing with a pressing die having a protruded cutting edge. In addition, unlike the cutting process at the time of forming the groove, there is no generation of cutting noise and cutting chips when forming the cuts.

The notch (10) has a small contribution to the convex deformability and a large contribution to the concave deformability in the flexibility of the flooring material. By forming the cut (10), It is possible to improve the concave deformability and improve the sound insulation and the like while suppressing the increase in the convex deformability and securing the floor material strength and the like.

However, the base of the cut (10), that is, the cut position on the bottom surface of the back groove (5) is slightly open because the base material (1) is compressed. The convex deformability is improved as compared with the case where no is formed.

The notch (10) preferably considers the tip position of the notch (10) with respect to the flooring material, rather than the depth of the notch itself.

That is, as shown in FIG.
When a plywood is used, it is preferable that the tip of the cut (10) is located at the second layer veneer (1b) from above the plywood substrate (1). That is, by adopting this configuration, the effect of the formation of the notch (10) described above can be obtained.
Can be obtained reliably.

In the present invention, when the cutting tip is located on the second layer veneer (1b), the cutting tip reaching the lower surface of the front veneer (1a), that is, the notch (10) is displayed. What includes only the veneer (1a) is also included.

When forming the cuts (5), it is preferable to adjust the cut amount in consideration of the upward cracks. For example, when the cut (10) is formed leaving only the front veneer (1a), the cutting edge of the cutting blade is set so as not to reach the lower surface of the front veneer (1a). Table veneer (1
What is necessary is just to reach the lower surface of a).

When the cutting tip is located on the lower surface of the veneer veneer (1a), the veneer veneer (1a) is not cracked due to the fiber direction and no cut is formed. (1a) Further, the strength of the floor material can be sufficiently ensured.

When plywood is used as the base material (1), the fiber direction of the veneer where the groove bottom of the back groove (5) is located is orthogonal to the length direction of the cut (10). As the remaining margin of the veneer on which the groove bottom is located is smaller, that is, as the number of fibers orthogonal to the cutting blade is smaller, the cutting operation can be performed more easily.

In the present invention, the notch (10) may be formed in all of the back groove (5), or the notch (10) may be formed in only a part of the back groove (5). good. Further substrate (1)
In the case where there is a back groove (5) in the width direction and a back groove (5) in the length direction, the notch (10) is not formed in the back groove (5) in the length direction. The cut (10) may be formed in part or all of the back groove (5).

In the present invention, as shown in FIG. 3, it is preferable to laminate a backing material (4) made of a buffer material and / or a soft material on the back surface side of the base material (1). That is, when the backing material (4) is laminated, the conformability to the floor substrate and the sound insulation can be further improved.

As the cushioning material for the backing material, a non-woven fabric or the like is preferably used in addition to an independent foam of a synthetic resin such as urethane resin, an olefin resin such as polyethylene or polypropylene, a rubber or a synthetic rubber, a continuous foam, or a continuous foam. Of course, these may be used alone or in combination.

As the soft material for the backing material, non-foamed or low foamed materials such as urethane resin, synthetic resin such as olefin resin such as polyethylene and polypropylene, asphalt, rubber and synthetic rubber, and iron powder A material filled with a high specific gravity substance such as lead, lead powder, barium sulfate or the like can be suitably used, and these may be used alone or in combination.

As the backing material (4), a combination of the cushioning material and the soft material may be used. For example, a sound insulation / damping sheet (a soft sheet made of a soft synthetic resin or asphalt mixed with a high specific gravity substance such as barium sulfate and lead powder), a buffer sheet (a foam sheet made of rubber, synthetic resin, etc.), Two or more types of buffer materials such as nonwoven fabrics may be laminated.

The wooden flooring material of the present invention having the above-described structure is
Usually, it is laid directly on a floor base such as a flat base.

As a plane ground, a particle board,
Floor substrate made of wood board such as oriented strand board, wafer board, reinforced concrete (RC construction),
In addition to concrete floor bases such as precast concrete (PC) and lightweight cellular concrete boards, floor bases consisting of double floors supporting plate materials and panels with support materials, and assembled floors such as OA floors is there.

As described above, in the wooden flooring material of the present invention, since the notch is formed at the bottom of the back groove (5), the recess is formed even if the back groove (5) is not formed more deeply than necessary. Deformability can be sufficiently ensured. Therefore, for example, even if an impact is applied to the floor material surface, the propagation of the impact sound can be sufficiently prevented by the concave deformation, and the sound insulation can be improved.

Further, since the back groove (5) does not need to be formed deeper than necessary, sufficient strength can be ensured, and the convex deformability in which the floor material surface becomes convex can be appropriately suppressed.
Therefore, when the flooring material is lifted with the surface thereof facing upward, with the middle portion or the end portion, it is possible to prevent the material from being greatly bent or bent in a mountain shape, and the flooring material can be easily handled. It can be carried out.

Further, in the wooden flooring material of the present invention, since it is not necessary to form the back groove (5) deeply, cutting dust and cutting noise can be reduced at the time of back groove processing by a circular saw or the like.
Circular saw wear can also be reduced.

The back groove (5) can secure an appropriate convex deformation property, and the back groove (5) and the cut (10) can secure sufficient concave deformation property, so that sufficient flexibility can be obtained. Therefore, even if there is unevenness in the floor substrate, the floor substrate has good adaptability to the floor substrate and can be constructed using only the adhesive without using nails.

[0065]

EXAMPLES Examples related to the present invention and comparative examples for verifying the effects will be described below.

[0066]

[Table 1]

<Examples> As shown in Table 1 and FIG. 5A, the thicknesses were 1.1 mm, 2.3 mm, and 1.7 in order from the top.
mm, 2.3 mm, 1.3 mm veneer (1a)-(1
e) is a 5-ply plywood (8.7 mm thick, 145 mm wide, 9 cm long) obtained by laminating the fiber directions alternately orthogonally.
09mm) as a base material (1), an intervening layer (3) made of paper having a thickness of 0.049 mm is laminated on the surface of the base material (1), and the surface of the intervening layer (3) is A flooring substrate (100) on which a decorative material (2) made of a veneer veneer having a thickness of 0.25 mm was laminated was prepared.

In this flooring substrate (100), the length direction of the flooring substrate (100) and the fiber direction of the veneer front veneer (1a) as the base material (1) are arranged in parallel, and the decorative material is also provided. Fiber direction of veneer as (2) and front veneer (1a)
And the fiber direction are arranged in parallel.

On the back surface of the base material (1) of the floor material substrate (100), a number of back grooves (5) were formed in parallel with the width direction using a circular saw. At this time, the groove width is 1.5 m
m, the groove interval was set to 12 mm, and the groove depth was set to 4.4 to 4.6 mm.

A notch (10) having a depth of 1.1 to 1.2 mm was formed in the bottom of the back groove (5) in parallel with the back groove (5).

The surface side of the substrate (1) is
As in (a), front grooves (20) and (21) were formed vertically and horizontally. Also, as shown in FIG. 4, on the back surface side of the base material (1), a portion corresponding to the front groove (20) in the width direction is set to have a large interval between the back grooves (5). In addition, several back grooves having a depth of 2.4 mm without cuts in the length direction were formed supplementarily.

Further, on the back surface of the substrate (1), a foaming ratio of 45
2.3mm thick polyurethane resin foam sheet (4 times
a) and a backing material (4) composed of a laminated sheet (thickness: 4.3 mm) in which a polyethylene resin foam sheet (4b) having an expansion ratio of 25 and a thickness of 2.0 are laminated on a polyurethane resin foam sheet ( 4a) was laminated on the outer surface side to obtain a wooden floor material of the example.

Although not shown in the drawings, the actual end processing for joining the floor materials is performed on the peripheral end surface of the wooden floor material.

<Comparative Example 1> As shown in Table 1 and FIG. 5B, the depth (5.5 to 5.7 mm) of the back groove (5) is different and the cut (10) is formed. Comparative Example 1 except that a floor material having the same configuration
Wood flooring.

<Comparative Example 2> As shown in Table 1 and FIG. 5 (c), a flooring material having the same configuration as that of the above-described embodiment was formed except that the cuts (10) were not formed. The wooden floor material of Comparative Example 2 was used.

<Evaluation>

[Table 2]

1. Evaluation of Cutting Ability As shown in Table 2, the loudness of cutting noise, the amount of cutting chips generated, and the degree of wear of the saw blade were measured for each of the wood flooring materials when the back groove (5) was formed. However, Comparative Example 1
In the case of the wooden flooring material, all of these measured values were larger than those of the wooden flooring material of Example and Comparative Example 2.

2. Evaluation of unevenness deformability The unevenness deformability (flexibility) of each wooden floor material was evaluated before the backing material (4) was laminated.

That is, the amount of bending (= arrow height) when both ends were supported at a span of 800 mm was measured with reference to the arrow height when each floor material was placed flat. At the time of this measurement, the amount of deflection (concave deformation) of each flooring with its surface facing up
And the amount of flexure (convex deformability) with the back face up was measured. Table 2 shows the results. As shown in the table, it can be seen that the flooring material of Example 1 has sufficient concave deformability while securing appropriate convex deformability (sufficient strength). On the other hand, although the floor material of Comparative Example 1 has sufficient concave deformability, the convex material is too large to obtain sufficient strength, and the floor material of Comparative Example 2 has convex deformability. Although it is small and has high strength, the concave deformation property is too small, and there is a concern that sound insulation properties, adaptability to a floor base, and the like are concerned.

3. Evaluation of sound insulation The floor impact sound level of each floor material was measured by a tapping machine according to JIS A1418. FIG. 6 is a graph showing the relationship between the octave band center frequency and the impact sound level based on the measurement results.
Shown in In these figures and tables, “L-5”
5 "," L-50 "and" L-45 "are sound insulation grade L-5.
The reference values of 5, L-50, L-45, and "slab" indicate the measured values only on the floor base where no floor material is present.

As is clear from the above measurement results, the floor material of the example has the same excellent sound insulation performance as the floor material of Comparative Example 1 having a deep groove depth, and has a sound insulation class equivalent to L-45. You can see that it is. On the other hand, the floor material of Comparative Example 2 was inferior in the sound insulation performance even though the groove depth was the same as the example, and the sound insulation grade was only equivalent to L-55.

[0082]

As described above, according to the wooden flooring material of the present invention, since the notch is formed at the bottom of the back groove, the concave deformability can be reduced even if the back groove is not formed more deeply than necessary. Sufficient securing can be achieved, and sound insulation can be improved. Also, since it is not necessary to form the back groove deeper than necessary, sufficient strength can be ensured, and the convex deformability in which the floor material surface becomes convex can be suppressed small, with the floor material facing up When lifted, it can be prevented from bending greatly or bending,
Floor materials can be handled easily. Further, since it is not necessary to form the back groove deeply, it is possible to reduce cutting chips and cutting noise during back groove processing with a circular saw or the like, and it is also possible to reduce wear of the circular saw. In addition, the back groove and the cut have an effect that sufficient flexibility can be obtained, and sufficient adaptability to the floor substrate can be ensured.

In the present invention, when plywood is used as the base material, the occurrence of cracks during the formation of cuts can be reduced or prevented, so that the advantage that the cut amount can be accurately controlled is provided. is there.

Further, in the present invention, when a backing material is laminated on the back surface of the base material, the conformability to the floor substrate and the sound insulation are improved.
There is an advantage that it can be further improved.

Further, in the present invention, when the back groove is formed at a predetermined depth, there is an advantage that more appropriate concave deformability can be obtained, and the above effect can be obtained more reliably. .

Further, in the present invention, when the length direction of the cut is formed substantially in the same direction as the width direction of the base material, there is an advantage that flexibility can be reliably provided in the length direction of the floor material.

Further, in the present invention, when the cutting tip is located in the single layer of the base material second layer, it is possible to further improve the concave deformability while giving a more appropriate convex deformability. There are advantages.

Further, in the present invention, when the length direction of the cut is substantially the same as the fiber direction of the second layer veneer, the concave deformability can be improved while imparting a more appropriate convex deformability. There is an advantage that it can be further improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first wooden flooring material related to the present invention, wherein FIG. 1 (a) is a plan view and FIG. 1 (b) is a rear view.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a cross-sectional view showing a second wood flooring related to the present invention.

FIG. 4 is a rear view showing a third wooden flooring material according to the present invention.

5A is a sectional view showing a wooden flooring as an embodiment related to the present invention, and FIG. 5B shows a wooden flooring as a comparative example 1 which deviates from the gist of the present invention. FIG. 4C is a sectional view showing a wooden flooring as Comparative Example 2 which deviates from the gist of the present invention.

FIG. 6 is a graph showing the relationship between the octave band center frequency and the floor impact sound level in the wooden floor materials of the example and the comparative example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Base material 1a-1e ... Single plate 2 ... Decorative material 3 ... Intervening layer 4 ... Backing material 5 ... Back groove 10 ... Cut

Claims (7)

[Claims] 1. A wooden flooring material provided with a decorative material on a front surface side of a base material, wherein a plurality of back grooves are formed in parallel on a back surface of the base material, and a back surface is provided on a bottom of the back groove. A wooden flooring characterized in that a cut is formed in substantially the same direction as the groove. 2. The wooden flooring material according to claim 1, wherein the base material is made of a plywood in which a plurality of veneers are laminated with their fiber directions alternately orthogonal to each other. 3. The wooden flooring material according to claim 1, wherein a backing material made of a cushioning material and / or a soft material is laminated on a back side of the base material. 4. The wooden flooring material according to claim 1, wherein said back groove is formed at a depth of at least half the thickness of said base material. 5. The substrate according to claim 1, wherein the substrate is formed in a long plate shape, and a length direction of the cut is set substantially in the same direction as a width direction of the substrate. Wood flooring described in. 6. The wooden flooring material according to claim 2, wherein a tip of said cut is located on a veneer of a second layer from above in said base material. 7. The wood flooring according to claim 6, wherein the length direction of the cut is set substantially in the same direction as the fiber direction of the second veneer.