JP7779669B2 - Heat storage board - Google Patents

Description

The present invention relates to a heat storage board with sound insulation properties.

In order to improve sound insulation, sound-insulating flooring has been proposed that includes a wooden base material with multiple sound-insulating grooves formed on its back surface and a buffer sheet attached to the back surface of the wooden base material (see, for example, Patent Document 1). With this sound-insulating flooring, when impact noise occurs on the surface of the wooden base material, the impact noise can be reduced by the sound-insulating grooves formed from the surface of the wooden base material to the back surface of the wooden base material.

Japanese Patent Application Laid-Open No. 2015-135017

Incidentally, a heat storage sheet is sometimes used to increase the heat storage capacity of a board. When a heat storage sheet is applied to a sound-insulating board, such as the sound-insulating floor shown in Patent Document 1, heat enters from the surface side of the wooden base material, so the heat storage sheet is placed between the wooden base material and the buffer sheet. In this case, the heat storage sheet is attached to the back side of the wooden base material, but it has been found that this does not sufficiently reduce the impact noise generated on the surface of the board.

The present invention was made in consideration of these points, and its purpose is to provide a heat storage board that can achieve both heat storage and sound insulation.

In light of the above issues, the inventors conducted extensive research and found that using a heat storage sheet makes it difficult to reduce low-frequency impact noise (for example, noise in the frequency range around 125 Hz to 250 Hz). Furthermore, as the inventors continued their research, they discovered that this impact noise is easily reduced by the bending (deformation) of the wood base material. However, as mentioned above, they discovered that if a heat storage sheet is attached to the entire back surface of the wood base material, when low-frequency impact noise occurs on the surface of the heat storage board, the heat storage sheet will restrict the bending of the wood board, making it impossible to sufficiently reduce the impact noise.

The present invention is based on new findings by the inventors, and the heat storage board according to the first invention comprises at least a wooden base material having a plurality of sound-insulating grooves formed on its rear surface, a flexible heat storage sheet attached to the rear surface of the wooden base material, and a backing material attached to the rear surface of the heat storage sheet, wherein wide grooves that are wider than the width of the sound-insulating grooves and shallower than the depth of the sound-insulating grooves are formed on the rear surface of the wooden base material, and the heat storage sheet is attached to the rear surface of the wooden base material so as to leave groove spaces formed in the wide grooves.

According to the first invention, by adhering a heat storage sheet to the back surface of a wooden base material, it is possible to store heat input from the wooden base material. When a heat storage sheet is adhered to a wooden base material, the sound insulation of the heat storage board is likely to decrease. However, according to the present invention, by providing wide grooves on the back surface of the wooden base material, separate from the sound insulation grooves, that are wider and shallower than the sound insulation grooves, a groove space is formed between the heat storage sheets by the wide grooves. This groove space can improve the sound insulation of the heat storage board.

Furthermore, because the heat storage sheet is attached to the back surface of the wooden base material so as to leave the groove space formed in the wide groove, the area of the back surface of the wooden base material to which the heat storage sheet is attached can be reduced. As a result, the wooden base material is less likely to be restrained by the heat storage sheet. As a result, the impact energy acting on the wooden base material is absorbed by the bending of the wooden base material, reducing the generated noise.

In a preferred embodiment of the first aspect of the present invention, the sound-insulating grooves and the wide grooves are formed in multiple numbers along at least the short side direction of the wood base material, and the sound-insulating grooves and the wide grooves are formed so as to overlap.

In this aspect, by forming multiple sound-insulating grooves along the short side, the impact energy acting on the wood base material is absorbed by the deflection of the wood base material, reducing the noise generated. In addition, because the sound-insulating groove space and the wide groove space are formed continuously, the sound generated within these spaces can be effectively absorbed.

In a preferred embodiment of the first invention, the surface of the heat storage sheet that is attached to the wooden base material has multiple ridges formed on it, and the heat storage sheet has the ridges attached to the back surface of the wooden base material so as to leave recessed spaces between adjacent ridges.

According to this aspect, the sound insulation properties of the heat storage board can be improved by the recessed spaces formed between adjacent ridges. Furthermore, because the heat storage sheet is attached to the back surface of the wooden base material so as to leave recessed spaces in the heat storage sheet, the adhesion area of the back surface of the wooden base material to the heat storage sheet can be reduced. As a result, the wooden base material is less likely to be restrained by the heat storage sheet. As a result, impact energy acting on the wooden base material is absorbed by the deflection of the wooden base material, reducing the sound generated by the heat storage board.

The following describes a heat storage board according to the second invention. The heat storage board according to the second invention comprises at least a wooden base material having a plurality of sound-insulating grooves formed on its rear surface, a flexible heat storage sheet attached to the rear surface of the wooden base material, and a backing material attached to the rear surface of the heat storage sheet. The surface of the heat storage sheet that is attached to the wooden base material has a plurality of ridges formed on it, and the ridges of the heat storage sheet are attached to the rear surface of the wooden base material so as to leave recessed spaces between adjacent ridges.

According to the second invention, by attaching a heat storage sheet to the back surface of the wooden base material, it is possible to store heat input from the wooden base material. When such a heat storage sheet is provided, the sound insulation of the heat storage board tends to decrease. However, according to the present invention, in addition to the sound-insulating grooves, the heat storage sheet has ridges attached to the back surface of the wooden base material so as to leave recessed spaces formed between adjacent ridges. This recessed space effectively absorbs sound, improving the sound insulation of the heat storage board.

Furthermore, because the heat storage sheet is attached to the back surface of the wooden base material in a way that leaves a recessed space in the heat storage sheet, the area of the back surface of the wooden base material to which the heat storage sheet is attached can be reduced. As a result, the wooden base material is less likely to be restrained by the heat storage sheet. As a result, the impact energy acting on the wooden base material is absorbed by the bending of the wooden base material, reducing the generated noise.

In a preferred embodiment of the second invention, the sound-insulating grooves and the protruding strips are formed in multiple locations along at least the short side of the wood base material, and the protruding strips along the short side are attached at positions away from the sound-insulating grooves along the short side.

In this embodiment, multiple sound-insulating grooves and ridges are formed along at least the short side of the wooden base material. The ridges along the short side restrain the wooden base material, making it easier for the wooden base material to flex in the longitudinal direction. As a result, the impact energy acting on the wooden base material is absorbed by the flexure of the wooden base material, reducing the generated noise.

The heat storage sheet according to the first and second inventions is not particularly limited as long as it has heat storage properties, but in a more preferred embodiment, the heat storage sheet is an elastic sheet in which heat storage material is dispersed in a base material made of foamed resin. In this embodiment, by making the heat storage sheet an elastic sheet, the impact energy from the wood base material is absorbed by the heat storage sheet through compressive deformation, thereby reducing the noise generated by the heat storage board.

The heat storage board of the present invention can achieve both heat storage and sound insulation.

1 is an exploded perspective view of a heat storage board according to a first embodiment, viewed from above. FIG. FIG. 2 is an exploded perspective view of the heat storage board according to FIG. 1 as viewed from below. 1A is an enlarged view of a main part of the thermal storage board shown in FIG. 1, FIG. 1B is a modified example of FIG. 1A, and FIG. 1C is another modified example of FIG. 1A. FIG. 2 is an enlarged view for explaining a main part of the heat storage sheet shown in FIG. 1 . FIG. 10 is an exploded perspective view of a heat storage board according to a second embodiment, viewed from above. FIG. 6 is an exploded perspective view of the heat storage board according to FIG. 5 as viewed from below. 6A is an enlarged view of a main part of the heat storage board shown in FIG. 5, and FIGS. 6B to 6F are modified examples of FIG. 6A. FIG. 11 is an exploded perspective view of a heat storage board according to a third embodiment, viewed from above. FIG. 9 is an exploded perspective view of the heat storage board according to FIG. 8 as viewed from below. 9A is an enlarged view of a main part of the thermal storage board shown in FIG. 8, and FIGS. 9B and 9C are modified examples of FIG. 9A.

The thermal storage board according to an embodiment of the present invention and its variations will be described with reference to Figures 1 to 10.

[First embodiment (first invention)]
The configuration of the thermal storage board 1A according to the first embodiment will be briefly described below. Fig. 1 is an exploded perspective view of the thermal storage board according to the first embodiment as viewed from above. Fig. 2 is an exploded perspective view of the thermal storage board according to Fig. 1 as viewed from below. Fig. 3(a) is an enlarged view of a main part of the thermal storage board shown in Fig. 1, Fig. 3(b) is a modified example of Fig. 3(a), and Fig. 3(c) is another modified example of Fig. 3(a). Fig. 4 is an enlarged view for explaining a main part of the thermal storage sheet shown in Fig. 1.

As shown in Figure 1, the heat storage board 1A according to the first embodiment is included in the first invention and is a board with sound insulation and heat storage properties. Figure 1 shows an example in which the heat storage board 1A is applied to flooring, but it may also be applied to building materials such as wall materials.

As shown in Figures 1 and 2, the heat storage board 1A comprises at least a wooden base material 11 having a plurality of sound-insulating grooves 21 formed on the back surface 11g, a flexible heat storage sheet 12 attached to the back surface 11g of the wooden base material 11, and a backing material 13 attached to the back surface 12g of the heat storage sheet 12.

1. Regarding the Wood Base Material 11 The wood base material 11 is a wood-based base material having a short side direction X and a long side direction Y. In this embodiment, the surface decorative material and the base material are laminated, for example, by bonding, but the surface decorative material does not necessarily have to be laminated. For example, the surface decorative material can be a decorative veneer, a resin decorative sheet, a sawn board, or a sliced veneer. Instead of the surface decorative material, the surface of the base material may be subjected to decorative printing, such as UV-curable inkjet printing or gravure printing after appropriate surface treatment.

Base materials include plywood, particle board (PB), wood fiberboard (MDF, insulation board, hardboard, etc.), oriented strand board, OSB, LVL, laminated wood, and solid wood, and these may be heat-treated or chemically treated, or may be composite wood base materials made by laminating two or more types of these.

As shown in Figures 1 and 2, male and female inseminations 11a and 11b are formed around the periphery of the wooden substrate 11 (specifically, the base material). When laying the thermal storage boards 1A on the subfloor, multiple thermal storage boards 1A can be connected by joining the male and female inseminations 11a and 11b of adjacent thermal storage boards 1A. The thickness (apparent thickness) from the front to the back of the wooden substrate 11 is preferably 6 to 12 mm, and more preferably 8 to 10 mm.

Furthermore, in this embodiment, a plurality of sound-insulating grooves 21, 21, ... are formed on the back surface 11g of the wooden base material 11. The multiple sound-insulating grooves 21, 21, ... are formed at a predetermined pitch along the short-side direction X and long-side direction Y of the wooden base material 11. It is preferable that the pitch of the sound-insulating grooves 21 be in the range of 3 to 1000 mm, the groove width be in the range of 0.3 to 10 mm, and the depth be in the range of 1 to 10 mm. This allows the wooden base material 11 to bend favorably when a load such as an impact load acts on the surface of the heat storage board 1A (i.e., the surface of the wooden base material 11).

In this embodiment, multiple sound-insulating grooves 21, 21, ... are formed so that sound-insulating grooves 21 along the longitudinal direction Y intersect with sound-insulating grooves 21 along the lateral direction X. However, as long as the above-mentioned deflection effect can be expected, multiple sound-insulating grooves 21 may be formed along only one of the directions, or multiple sound-insulating grooves 21 may be formed along a direction intersecting the lateral direction X and the longitudinal direction Y, and the widths, depths, etc. of each sound-insulating groove 21 may differ. A wide groove 22 is also formed in the wood substrate 11, the details of which will be described later.

2. Regarding the heat storage sheet 12 The heat storage sheet 12 is disposed so as to cover the back surface 11g of the wood base material 11. In this embodiment, the heat storage sheet 12 is a heat storage sheet having flat surfaces on the front surface 12f and the back surface 12g.

The heat storage sheet 12 is a sheet containing a latent heat storage material that stores heat by converting from a liquid phase to a solid phase. Preferably, the latent heat storage material does not leach out of the heat storage sheet 12 when in the liquid phase. In this embodiment, as shown in FIG. 4, the heat storage sheet 12 is a sheet-like member in which heat storage particles 12b, in which the latent heat storage material is encapsulated in microcapsules, are dispersed in a resin substrate 12a. The heat storage sheet 12 is preferably flexible. The microcapsules and resin substrate 12a may be either a thermosetting resin or a thermoplastic resin. The resin is not limited as long as the latent heat storage material does not leak out of the microcapsules. The resin substrate 12a may also be a thermoplastic resin that softens at or below the heating temperature during molding. Examples of the thermoplastic resin constituting the resin substrate 12a include vinyl chloride, and the heat storage sheet 12 may also be a foamed sheet obtained by foaming the resin substrate 12a.

The phase change temperature (melting point) of the latent heat storage material from the liquid phase to the solid phase is preferably 18 to 25°C. Examples of latent heat storage materials include saturated aliphatic hydrocarbons such as n-paraffin and paraffin wax, typically having 16 to 24 carbon atoms and composed of n-hexadecane, n-heptadecane, n-octadecane, n-nonadecane, etc., or mixtures thereof; mono- or polyunsaturated aliphatic hydrocarbons such as linear α-olefins, typically having 16 to 24 carbon atoms and composed of 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, etc., or mixtures thereof; long-chain fatty acids such as octanoic acid, capric acid, lauric acid, myristic acid, etc., or mixtures thereof; esters of the above fatty acids, and polyether compounds such as polyethylene glycol. For example, if the material melts at 28°C, n-octadecane is selected, and if the material melts at 18°C, n-hexadecane is selected. Furthermore, multiple latent heat storage materials with different melting points as described above may be mixed and used.

The heat storage sheet 12 may also be a bag made of metal, resin, or a film laminated with these, with the latent heat storage material sealed inside. Alternatively, the heat storage sheet 12 may be made of a latent heat storage material that gels above its phase change temperature. In this embodiment, the latent heat storage material changes from a solid state to a gel state above its phase change temperature, so that the shape of the latent heat storage material can be easily maintained even when the temperature exceeds its phase change temperature.

Furthermore, as disclosed in International Publication WO 2015/174523, which has already been filed by the applicant, the heat storage sheet 12 may contain a heat storage material composition containing a latent heat storage material and a hydrogenated styrene-based thermoplastic elastomer. Examples of hydrogenated styrene-based thermoplastic elastomers include at least one type (or a mixture of two or more types) selected from the group consisting of styrene-ethylene/butylene-styrene block copolymer (SEBS), styrene-ethylene/propylene block copolymer (SEP), styrene-ethylene/propylene-styrene block copolymer (SEPS), and styrene-ethylene-ethylene/propylene-styrene block copolymer (SEEPS).

3. Regarding the Backing Material 13 The backing material 13 is disposed on the back side of the heat storage sheet 12. The backing material 13 may be a nonwoven fabric or a woven fabric.

The backing material 13 may be made of resin fibers such as polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, and polyamide resins including nylon, or natural fibers such as cotton and wool. The backing material 13 may also be a non-porous resin sheet. For example, the backing material 13 may be an impact-absorbing sheet (a sheet with cushioning properties). Examples of impact-absorbing sheets include foamed resin sheets, and foamed resins include polyurethane resin, polystyrene resin, polyethylene resin, and polypropylene resin. Among these, polyurethane resin, which has a high elastic deformation rate in the compression direction, is preferred.

4. Soundproof Structure In this embodiment, a soundproof structure is formed by the wooden base material 11 and the heat storage sheet 12. Specifically, wide grooves 22 are formed on the back surface 11g of the wooden base material 11. The wide grooves 22 are wider than the width of the sound-insulating grooves 21 and shallower than the depth of the sound-insulating grooves 21. Specifically, as shown in FIG. 3A, the depth D2 of the wide grooves 22 is shallower than the depth D1 of the sound-insulating grooves 21, and the groove width W2 of the wide grooves 22 is wider than the groove width W1 of the sound-insulating grooves 21. For example, it is preferable that the depth D2 of the wide grooves 22 is in the range of 0.05 to 0.50 times the depth D1 of the sound-insulating grooves 21, and the groove width W2 of the wide grooves 22 is in the range of 2 to 30 times the groove width W1 of the sound-insulating grooves 21.

In this embodiment, as shown in Figures 2 and 3(a), a plurality of sound-insulating grooves 21 and wide grooves 22 are formed along at least the short-side direction X of the wood substrate 11, and the sound-insulating grooves 21 and wide grooves 22 are formed so as to overlap. In this embodiment, the wide grooves 22 are formed along the short-side direction X, but the wide grooves 22 may also be formed along the longitudinal direction Y, for example. In this case, the sound-insulating grooves 21 and wide grooves 22 along the long-side direction are formed so as to overlap.

The wooden base material 11 and the heat storage sheet 12 are bonded together via an adhesive. Specifically, as shown in FIG. 3, the heat storage sheet 12 is bonded to the back surface 11g of the wooden base material 11 so as to leave the groove space S2 formed in the wide groove 22. The heat storage sheet 12 and the back surface material 13 are also bonded together via an adhesive.

The adhesive used to bond the wood base material 11 and the heat storage sheet 12, and the adhesive used to bond the heat storage sheet 12 and the backing material 13 are not particularly limited as long as they can ensure adhesion. Therefore, the adhesive only needs to be formed as an adhesive layer at the interface between these materials, and it is preferable that no adhesive be attached to the surface 12f of the heat storage sheet 12 facing the wide groove 22. As a result, the surface 12f of the heat storage sheet 12 facing the wide groove 22 is not hardened by the adhesive, and the surface 12f of the heat storage sheet 12 can absorb sound transmitted to the space S2 of the wide groove 22.

Examples of adhesives include water-based adhesives such as urea-melamine resin adhesives or ethylene-vinyl acetate co-condensation resin adhesives such as modified vinyl acetate adhesives; adhesives that harden through a chemical reaction in response to moisture, such as one-component polyurethane adhesives and silicone adhesives; and hot-melt adhesives such as polyamide adhesives and EVA adhesives. Other adhesives that can be used include those made by dissolving the adhesive resin in a hydrocarbon organic solvent.

In this embodiment, by adhering a heat storage sheet 12 to the back surface 11g of the wooden base material 11, it is possible to store heat input from the wooden base material 11. Affixing a heat storage sheet 12 to the wooden base material 11 tends to reduce the sound insulation of the heat storage board 1A. However, in this embodiment, wide grooves 22, which are wider and shallower than the sound insulation grooves 21, are provided on the back surface 11g of the wooden base material 11 in addition to the sound insulation grooves 21. This creates a groove space S2 between the wooden base material 11 and the heat storage sheet 12, in addition to the space S1 created by the sound insulation grooves 21. This groove space S2 improves the sound insulation of the heat storage board 1A.

In particular, by forming multiple sound-insulating grooves 21, 21, ... along the short direction X, impact energy acting on the wooden base material 11 is absorbed by the deflection of the wooden base material 11, reducing sound generated on the surface side of the wooden base material 11. In addition, as shown in Figure 3(a), the space S1 of the sound-insulating groove 21 and the space S2 of the wide groove are formed continuously (communicate), so sound generated within these spaces S1 and S2 can be effectively absorbed.

For this reason, for example, as shown in the modified example of Figure 3(b), wide grooves 22 may be formed so as to extend to one side of the sound-insulating groove 21. However, if wide grooves 22 are provided so as to extend to both sides of the sound-insulating groove 21 as shown in Figure 3(a), the sound transmitted from the sound-insulating groove 21 will be dispersed in the space S2 of the wide groove 22, thereby improving the sound insulation of the heat storage board 1A. Note that the sound-insulating groove 21 shown in Figure 3(b) may also be formed along the longitudinal direction Y of the wood substrate 11.

The heat storage sheet 12 shown in Figures 3(a) and 3(b) is attached to the back surface 11g of the wooden substrate 11 so as to leave the groove spaces S2 formed in the wide grooves 22. This allows the adhesion area of the heat storage sheet 12 on the back surface 11g of the wooden substrate 11 to be reduced compared to previous designs (those with only sound-insulating grooves 21). This makes it less likely that the wooden substrate 11 will be constrained by the heat storage sheet 12. As a result, the impact energy acting on the wooden substrate 11 is absorbed by the deflection of the wooden substrate 11, reducing the amount of noise generated. To achieve this effect, the adhesion area of the heat storage sheet 12 is preferably in the range of 30% to 70%, and more preferably 40% to 60%, of the total area of the back surface of the wooden substrate 11 when viewed in plan.

Therefore, for example, as shown in the modified heat storage board 1A in Figure 3(c), the same effect can be achieved even if the wide grooves 22 are formed in positions that are offset from the sound-insulating grooves 21. Even if the wide grooves 22 are formed in positions that are offset from the sound-insulating grooves 21 as shown in Figure 3(c), the spaces S2 of the wide grooves 22 intersect with the sound-insulating grooves 21 formed along the longitudinal direction of the wooden base material 11 and are therefore continuous with the spaces of the sound-insulating grooves 21 in the longitudinal direction, thereby improving sound absorption. Furthermore, the wide grooves 22 may also be formed along the longitudinal direction of the wooden base material 11 as shown in Figure 3(c).

[Second embodiment (first invention)]
A thermal storage board 1B according to a second embodiment will be described below with reference to Figures 5 to 7. The second embodiment is an embodiment included in the first invention, and differs from the first embodiment in the thermal storage sheet. Therefore, in the following Figures 5 to 7, the same components as those of the thermal storage board 1A of the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

Figure 5 is an exploded perspective view of the thermal storage board according to the second embodiment, viewed from above. Figure 6 is an exploded perspective view of the thermal storage board according to Figure 5, viewed from below. Figure 7(a) is an enlarged view of a main part of the thermal storage board shown in Figure 5, and Figures 7(b) to (f) are modified versions of (a).

As shown in Figure 5, in the heat storage board 1B of the second embodiment, a plurality of ridges 31, 31, ... are formed on the surface 12f of the heat storage sheet 12 that is attached to the wooden substrate 11. Each ridge 31 shown in Figure 5 is a wide ridge whose width is greater than its height, but this shape is not limited to this, and the width of the ridge may be equal to or narrower than its height. Grooves 32 are formed between the ridges 31, 31, and the grooves 32 form recessed spaces S3.

For convenience, Figure 5 shows a small number of ridges 31, but the width of the ridges 31 is preferably in the range of 4 to 60 mm, and the width of the grooves 32 is also preferably in the range of 4 to 60 mm. Here, as shown in Figure 7(a), the heat storage sheet 12 has the ridges 31 attached to the back surface 11g of the wood substrate 11 so as to leave recessed spaces S3 formed between adjacent ridges 31. In this embodiment, the groove width of the grooves 32 of the heat storage sheet 12 is wider than the groove width of the sound-insulating grooves 21.

Here, the heat storage sheet 12 having the ridges 31 may be integrally molded from the material shown in the first embodiment, for example, a material in which heat storage material is dispersed in a base material made of foamed resin as shown in Figure 4. However, the heat storage sheet 12 may also be produced by attaching string-like or linear members corresponding to the ridges 31 to a sheet material with a flat surface.

Alternatively, only the ridges 31 may be made of nonwoven fabric, with the remaining portions made of a heat-storing material. The density of the nonwoven fabric of the ridges 31 is preferably in the range of ^0.4 g/cm to ^1.0 g/cm, and the fiber diameter of the nonwoven fabric is preferably in the range of 0.5 μm to 15 μm.

In this embodiment, the sound insulation of the heat storage board 1A can be improved by the recessed spaces S3 of the recessed grooves 32 formed between adjacent ridges 31, 31. Furthermore, because the heat storage sheet 12 is attached to the back surface 11g of the wooden base material 11 so as to leave the recessed spaces S3 in the heat storage sheet 12, the adhesion area of the back surface 11g of the wooden base material 11 to the heat storage sheet 12 can be reduced. As a result, the wooden base material 11 is less likely to be restrained by the heat storage sheet 12. As a result, impact energy acting on the wooden base material 11 is absorbed by the deflection of the wooden base material 11, reducing the sound generated by the heat storage board 1B.

As shown in Figure 7(a), the recessed grooves 32 formed in the heat storage sheet 12 are formed to overlap the wide grooves 22 in the wooden base material 11, so the recessed spaces S3 of the recessed grooves 32 in the heat storage sheet 12 are continuous with the spaces S1 of the sound-insulating grooves 21 and the spaces S2 of the wide grooves 22 in the wooden base material 11. As a result, these continuous spaces S1 to S3 can improve the sound insulation of the heat storage board 1B.

Here, as shown in FIG. 7(b), the groove width of the recessed groove 32 may be narrower than the groove width of the wide groove 22. However, as shown in FIG. 7(a), by making the groove width of the recessed groove 32 wider than the groove width of the wide groove 22, it is possible to reduce the adhesion area of the heat storage sheet 12 on the back surface 11g of the wooden substrate 11. Furthermore, as shown in FIG. 7(c), the recessed groove 32 may be formed so as to extend beyond the wide groove 22. Even in this case, it is possible to reduce the adhesion area of the heat storage sheet 12 on the back surface 11g of the wooden substrate 11 compared to the heat storage board 1B in FIG. 7(b). This reduces the constraint of the heat storage sheet 12 on the wooden substrate 11 when the wooden substrate 11 bends, thereby improving the sound insulation of the heat storage board 1B.

Furthermore, as shown in Figure 7(d), the recessed grooves 32 formed in the heat storage sheet 12 may be formed so as to deviate from the wide grooves 22 in the wooden base material 11. Even in this case, the adhesion area between the heat storage sheet 12 and the back surface 11g of the wooden base material 11 can be reduced compared to the heat storage board 1A of the first embodiment shown in Figure 3(b). In this case as well, when the wooden base material 11 bends, the constraint of the heat storage sheet 12 on the wooden base material 11 can be reduced, thereby improving the sound insulation of the heat storage board 1B.

Furthermore, as shown in Figure 7(e), wide grooves 22 may be formed in a position away from the sound insulation grooves 21, and recessed grooves 32 may be formed in the heat storage sheet 12 so as to overlap the sound insulation grooves 21. This makes the space S1 of the sound insulation groove 21 and the recessed space S3 of the recessed groove 32 continuous, and these spaces can improve the sound insulation of the heat storage board 1B. Also, as shown in Figure 7(f), if wide grooves 22 are formed in a position away from the sound insulation grooves 21, and recessed grooves 32 of the heat storage sheet 12 are formed so as to overlap the sound insulation grooves 21 and wide grooves 22, these spaces can further improve the sound insulation of the heat storage board 1B.

In this way, the thermal storage board 1B may be provided with any one of the sound-insulating structures shown in Figures 7(a) to 7(f), or may include several of them. Furthermore, the thermal storage board 1B may be formed by applying any one of the thermal storage sheets 12 shown in Figures 7(a) to 7(f) to the wood substrate 11 shown in Figures 3(a) to 3(c) of the first embodiment.

[Third embodiment (second invention)]
A heat storage board 1C according to a third embodiment will be described below with reference to Figures 8 to 10. The third embodiment is included in the second invention, and differs from the second embodiment in the wood base material. Therefore, the same components as those of the heat storage board 1B according to the second embodiment are denoted by the same reference numerals in Figures 8 to 10 below, and detailed description thereof will be omitted.

Figure 8 is an exploded perspective view of the heat storage board according to the third embodiment, viewed from above. Figure 9 is an exploded perspective view of the heat storage board according to Figure 8, viewed from below. Figure 10(a) is an enlarged view of a main part of the heat storage board shown in Figure 8, and Figures 10(b) and 10(c) are modified versions of Figure 10(a).

As shown in Figures 8 to 10, the heat storage board 1C according to the third embodiment comprises a wooden base material 11 having a plurality of sound-insulating grooves 21 formed on its back surface 11g, a flexible heat storage sheet 12 attached to the back surface 11g of the wooden base material 11, and a backing material 13 attached to the back surface 12g of the heat storage sheet 12.

In this embodiment, sound-insulating grooves 21 are formed on the back surface 11g of the wooden base material 11, but wide grooves 22 are not formed. In this embodiment, similar to the heat storage sheet 12 of the second embodiment, a plurality of ridges 31, 31, ... are formed on the surface 12f of the heat storage sheet 12 that is attached to the wooden base material 11.

As in the second embodiment, each ridge 31 shown in Figure 8 is a wide ridge, with the ridge width being greater than the ridge height, but this shape is not limited to this and the ridge width may be equal to or smaller than the ridge height. Grooves 32 are formed between the ridges 31, 31, and recessed spaces S3 are formed in the grooves 32. The dimensions of the ridges 31 and the grooves 32 are the same as those in the ranges shown in the second embodiment.

In this embodiment, as shown in Figures 8, 10(a), etc., the convex strips 31 extending along the short side direction X are attached at positions that are offset from the sound-insulating grooves 21 extending along the short side direction X. Therefore, the convex strips 31 of the heat storage sheet 12 are attached to the back surface 11g of the wood substrate 11 so as to leave recessed spaces S3 formed between adjacent convex strips 31. Here, as in the second embodiment, the groove width of the recessed grooves 32 of the heat storage sheet 12 is wider than the groove width of the sound-insulating grooves 21. Furthermore, the groove depth of the recessed grooves 32 may be shallower than the groove depth of the sound-insulating grooves 21.

Here, the heat storage sheet 12 having the ridges 31 may be integrally molded from the material shown in the first embodiment, for example, a material in which heat storage material is dispersed in a base material made of foamed resin as shown in Figure 4. However, the heat storage sheet 12 may also be produced by attaching string-like or linear members corresponding to the ridges 31 to a sheet material with a flat surface. Alternatively, as shown in the second embodiment, only the ridges 31 may be made of nonwoven fabric, with the remaining parts made of a material with heat storage properties.

In this embodiment, the sound insulation of the heat storage board 1C can be improved by the recessed spaces S3 of the grooves 32 formed between adjacent ridges 31, 31. Furthermore, because the heat storage sheet 12 is attached to the back surface 11g of the wooden base material 11 so as to leave the recessed spaces S3 in the heat storage sheet 12, the adhesion area of the back surface 11g of the wooden base material 11 to the heat storage sheet 12 can be reduced compared to when the recessed grooves 32 are not provided. As a result, the wooden base material 11 is less likely to be restrained by the heat storage sheet 12. As a result, the deflection of the wooden base material 11 absorbs impact energy acting on the wooden base material 11, reducing the sound generated by the heat storage board 1C.

Similarly, in the third embodiment, by adhering a heat storage sheet 12 to the back surface 11g of the wooden base material 11, it is possible to store heat input from the wooden base material 11. When a heat storage sheet 12 is adhered to the wooden base material 11, the sound insulation of the heat storage board 1C tends to decrease. However, according to this embodiment, in addition to the sound insulation grooves 21, recessed grooves 32 are positioned opposite the back surface 11g of the wooden base material 11. Therefore, in addition to the space S1 created by the sound insulation grooves 21, a recessed space S3 created by the recessed grooves 32 is formed between the wooden base material 11 and the heat storage sheet 12. This groove space S3 can improve the sound insulation of the heat storage board 1C.

Furthermore, in this embodiment, in particular, a plurality of sound-insulating grooves 21 and protruding strips 31 are formed along at least the short-side direction X of the wood base material 11, and the protruding strips 31 along the short-side direction are attached at positions away from the sound-insulating grooves 21 along the short-side direction X. Therefore, as shown in Figure 10(a), in this embodiment, the space S1 of the sound-insulating groove 21 and the recessed space S3 of the heat storage sheet 12 are continuous. These continuous spaces can improve the sound insulation of the heat storage board.

Here, the heat storage sheet 12 is attached to the back surface 11g of the wooden base material 11 so as to leave a recessed space S3 in the heat storage sheet 12, thereby reducing the area of the back surface 11g of the wooden base material 11 to which the heat storage sheet 12 is attached. This makes it difficult for the wooden base material 11 to be restrained by the heat storage sheet 12. As a result, the impact energy acting on the wooden base material 11 is absorbed by the deflection of the wooden base material 11, reducing the generated noise.

Here, for example, as shown in the modified example of Figure 10(b), recessed grooves 32 may be formed so as to extend to one side of the sound-insulating groove 21. However, if recessed grooves 32 are provided so as to extend to both sides of the sound-insulating groove 21 as shown in Figure 10(a), the sound transmitted from the sound-insulating groove 21 is dispersed into the recessed space S3 of the recessed groove 32, thereby improving the sound insulation of the heat storage board 1C. Note that the sound-insulating groove 21 shown in Figure 3(b) may also be formed along the longitudinal direction Y of the wood substrate 11.

The heat storage sheet 12 shown in Figures 10(a) and 10(b) is attached to the back surface 11g of the wooden substrate 11 so as to leave the groove spaces S3 formed in the recessed grooves 32. This allows the adhesion area of the heat storage sheet 12 on the back surface 11g of the wooden substrate 11 to be reduced compared to previous designs (those with only sound-insulating grooves 21). This makes it less likely that the wooden substrate 11 will be constrained by the heat storage sheet 12. As a result, the impact energy acting on the wooden substrate 11 is absorbed by the deflection of the wooden substrate 11, reducing the amount of noise generated. To achieve this effect, the adhesion area of the heat storage sheet 12 is preferably in the range of 30% to 70%, and more preferably 40% to 60%, of the total area of the back surface of the wooden substrate 11 when viewed in plan.

Therefore, for example, as shown in the modified heat storage board 1C in Figure 10(c), the same effect can be achieved even if the recessed groove 32 is formed in a position that is offset from the sound-insulating groove 21. Even if the recessed groove 32 is formed in a position that is offset from the sound-insulating groove 21 as shown in Figure 10(c), the recessed space S3 of this recessed groove 32 intersects with the sound-insulating groove 21 formed along the longitudinal direction of the wooden base material 11 and is continuous with the space S1 of the longitudinal sound-insulating groove 21, so these spaces can improve sound absorption. Furthermore, as shown in Figure 10(c), the recessed groove 32 may also be formed along the longitudinal direction Y of the wooden base material 11.

The following describes an example of the present invention.

Example 1
A heat storage board corresponding to the first embodiment was fabricated. Specifically, a 9.0 mm thick wood substrate, a 3.0 mm thick heat storage sheet, and a 3.0 mm thick backing material were prepared. The wood substrate was made of plywood with a decorative material bonded to the surface. The back surface had multiple sound-insulating grooves 6.0 mm deep. Wide grooves 0.6 mm deep were formed along the short side direction at 10 mm intervals on the back surface of the wood substrate. The heat storage sheet was an elastic sheet in which microcapsules encapsulating a latent heat storage material were dispersed in a urethane foam resin. Next, these were bonded together with an adhesive so that the wide grooves remained open, to fabricate a heat storage board.

Example 2
A thermal storage board was fabricated in the same manner as in Example 1. The difference from Example 1 is that instead of providing wide grooves in the wood substrate, multiple ridges, each 10 mm wide and 10 mm pitch, and 1.7 mm high, were formed on the surface of the thermal storage sheet that was to be attached to the wood substrate, as in the third embodiment. These ridges were also made by dispersing microcapsules in a urethane foam resin.

Comparative Example 1
A thermal storage board was produced in the same manner as in Example 1. The difference from Example 1 is that a wood base material without wide grooves was used.

(Sound insulation test)
The thermal storage boards according to Examples 1 to 5 and Comparative Example 1 were measured for floor impact sound level reduction (hereinafter referred to as reduction) in accordance with JIS A 1418. The results are shown in Table 1.

The thermal storage boards of Examples 1 and 2 were found to reduce floor impact sound levels more than Comparative Example 1 in the frequency range of 125 Hz to 1 kHz. In particular, at a frequency of 125 Hz, the reduction in floor impact sound levels for the thermal storage boards of Examples 1 and 2 was about four times that of Comparative Example 1. This is thought to be because the thermal storage board of Comparative Example 1 has less space for sound absorption, and the wood base material is more tightly bound by the thermal storage sheet than in Examples 1 and 2.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various design modifications can be made without departing from the spirit of the present invention as set forth in the claims.

1A, 1B, 1C: Heat storage board, 11: Wood base material, 12: Heat storage sheet, 13: Backing material, 21: Sound insulation groove, 22: Wide groove, 31: Convex strip, X: Short direction, Y: Longitudinal direction

Claims (4)

A wood base material having a plurality of sound-insulating grooves formed on the back surface thereof;
A flexible heat storage sheet attached to the back surface of the wood base material;
A backing material attached to the back surface of the heat storage sheet,
A plurality of ridges are formed on the surface of the heat storage sheet that is attached to the wood base material,
The heat storage sheet has the protrusions attached to the back surface of the wood base material so as to leave recessed spaces between adjacent protrusions,
The sound-insulating grooves and the protrusions are formed in plural along at least the short side direction of the wood base material,
The heat storage board, characterized in that the convex stripes extending along the short side direction are attached at positions that are out of alignment with the sound insulating grooves extending along the short side direction. 2. The thermal storage board according to claim 1, wherein the thermal storage sheet is an elastic sheet in which a thermal storage material is dispersed in a base material made of foamed resin. A wide groove is formed on the back surface of the wood base material, the wide groove being wider than the groove width of the sound-insulating groove and shallower than the depth of the sound-insulating groove,
3. The heat storage board according to claim 1, wherein the heat storage sheet is attached to the back surface of the wood base material so as to leave a groove space formed in the wide groove. The sound-insulating grooves and the wide grooves are formed in plural along at least the short side direction of the wood base material,
The heat storage board according to claim 3, wherein the sound insulating groove and the wide groove are formed so as to overlap each other.