Fire-retardant chemical retaining boards, fire-resistant wood composite materials and fire-resistant wooden structural materials

Abstract

To provide a flame-retardant agent holding board and a fire-resistant woody composite material capable of being easily manufactured and achieving both thinness and fire-resistant performance.SOLUTION: A flame-retardant agent holding board 10 is used for forming a fire-resistant covering layer, and has a first direction X and a second direction Y orthogonal to the first direction X, and comprises a woody base material 20 having non-through opening holes 21, 22 on one surface side and the other surface side, respectively, and a flame-retardant agent-containing solid material 30 filled in the opening holes 21, 22, respectively. In the opening holes 21 on one surface side and the opening holes 22 on the other surface side, positions of center points 21a, 22a are shifted from each other in the first direction X or the second direction Y or in both the directions. A fire-resistant woody composite material has a structure in which a plurality of the flame-retardant agent holding boards 10 are laminated.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a fire retardant agent-holding board, a fire resistant wood composite material, and a fire resistant wooden structure. [Background technology]

[0002] Conventionally, various techniques have been proposed for the purpose of imparting fire resistance to wood. For example, Patent Document 1 describes a fire retardant support comprising a wood substrate having a plurality of openings and a fire retardant-containing solid material filled in the openings. Patent Document 1 also describes a fire-resistant wood composite material formed by laminating a plurality of fire retardant supports. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-59126 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the fire-resistant wood composite material of Patent Document 1, in order to obtain high fire resistance, it is desirable to control the positional relationship between the laminated flame retardant chemical supports. Specifically, it is desirable to laminate a plurality of flame retardant chemical supports with the positions of the apertures shifted. However, it is not necessarily easy to control the positions of the apertures of the laminated flame retardant chemical supports with high precision.

[0005] In addition, in Patent Document 1, the openings in the wood base material are through holes, so when the openings are filled with a solid material containing a flame retardant after the openings are formed, the solid material containing a flame retardant may come out of the openings. If the solid material containing a flame retardant comes out of the openings, it must be repaired manually, so it is not necessarily easy to put the manufacturing process of the fire-resistant wood composite material of Patent Document 1 into an production line. As described above, the fire-resistant wood composite material of Patent Document 1 has room for improvement in terms of ease of production. Furthermore, in order to improve the fire resistance of the fire-resistant wood composite material of Patent Document 1, it was necessary to increase the number of flame retardant agent holders to be laminated, and there was room for improvement in terms of improving the fire resistance while reducing the thickness of the fire-resistant wood composite material.

[0006] An object of the present invention is to provide a flame retardant agent holding board, a fire-resistant wood composite material, and a fire-resistant wooden structural material that can be easily manufactured and that achieves both thinness and fire resistance. [Means for solving the problem]

[0007] The present invention provides a flame retardant agent holding plate used for forming a fire-resistant coating layer, the flame retardant agent holding plate comprising a wood base material having a first direction and a second direction perpendicular to the first direction, and having non-through openings on each of one side and the other side, and a flame retardant agent-containing solid filled in each of the openings, wherein the openings on the one side and the openings on the other side have center points that are offset in the first direction or the second direction, or both.

[0008] The present invention also provides a fire-resistant wood composite material having a structure in which multiple flame-retardant chemical holding plates are laminated together, wherein the flame-retardant chemical holding plates are the flame-retardant chemical holding plates of the present invention.

[0009] The present invention also provides a fire-resistant wooden structural material comprising a load-bearing section made of a square timber and a fire-resistant coating layer covering three or four axial sides of the load-bearing section, wherein each of the fire-resistant coating layers covering each of the sides contains the flame-retardant agent holding plate of the present invention. Effect of the Invention

[0010] According to the present invention, it is possible to provide a flame retardant agent holding board, a fire-resistant wood composite material, and a fire-resistant wooden structural material that can be easily manufactured and that achieves both thinness and fire resistance. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view showing a fire-resistant wood composite material according to a preferred embodiment of the present invention. [Diagram 2] 2(a) is a plan view of part A in FIG. 1, and FIG. 2(b) is a cross-sectional view of one flame-retardant agent holding plate along line IIb-IIb in FIG. 2(a). [Diagram 3] FIG. 3 is a cross-sectional view showing a part of the cross section taken along line III-III in FIG. [Figure 4] FIG. 4 is a cross-sectional view showing a modified example of the laminated state of the flame-retardant agent holding plates, and corresponds to FIG. [Diagram 5] FIG. 5(a) is a cross-sectional view of a fire-resistant wooden structural material according to a preferred embodiment of the present invention, FIG. 5(b) is a modified example of the fire-resistant wooden structural material shown in FIG. 5(a), and FIG. 5(c) is a cross-sectional view of a fire-resistant wooden structural material according to another embodiment of the present invention. [Figure 6] FIG. 6 is a graph showing the results of measuring the temperature of the test specimen of Example 1 when a combustion test was performed on the test specimen. [Figure 7] FIG. 7 is a graph showing the results of measuring the temperature of the test specimen of Example 2 when a combustion test was performed on the test specimen. [Figure 8] FIG. 8(a) is a diagram showing the positions at which temperature changes were measured when a combustion test was conducted on the test specimen of Example 3, and FIG. 8(b) is a graph showing the results of measuring the temperature of the test specimen. [Figure 9] FIG. 9(a) is a diagram showing the positions at which temperature changes were measured when a combustion test was conducted on the test specimen of Example 4, and FIG. 9(b) is a graph showing the results of measuring the temperature of the test specimen. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention will now be described in detail based on preferred embodiments thereof. A fire-resistant wood composite material 1 according to a preferred embodiment of the present invention has a configuration in which a plurality of flame retardant agent holding plates 10 are laminated in the thickness direction, as shown in Fig. 1. In the fire-resistant wood composite material 1, two flame retardant agent holding plates 10 are laminated in the thickness direction Z. In a plan view, the flame retardant agent holding plates 10 have a first direction X and a second direction Y perpendicular to the first direction X. In the embodiment shown in Fig. 1, the two flame retardant agent holding plates 10 are laminated with the first direction X and the second direction Y aligned. The flame retardant agent holding plates 10 are used to form a fire-resistant coating layer.

[0013] As shown in Figures 2(a) and 2(b), the flame retardant agent holding plate 10 comprises a wood base material 20 and a flame retardant agent-containing solid material 30. The wood base material 20 has one surface S1 and another surface S2 in the thickness direction Z. The wood base material 20 has non-through openings 21, 22 on the one surface S1 side and the other surface S2 side, respectively. The flame retardant agent-containing solid material 30 is filled in the openings 21 on the one surface S1 side and the openings 22 on the other surface S2 side, respectively.

[0014] As described above, the flame retardant agent holding plate 10 includes the wood base material 20 having a plurality of openings 21, 22, and the flame retardant agent-containing solid material 30 filled in each of the openings 21, 22. With this configuration, the flame retardant agent holding plate 10 is cut off by the flame retardant agent-containing solid material 30 filled in each of the openings 21, 22 of the wood base material 20, so that when the flame retardant agent holding plate 10 burns, for example, large cracks are unlikely to occur in the flame retardant agent holding plate 10. Here, cutting off the edges means that the extension of the crack is stopped at the opening portion.

[0015] As shown in Fig. 2(b), the openings 21, 22 do not penetrate the wood base material 20. Specifically, the opening 21 on the one surface S1 side (hereinafter also referred to as the "one surface side opening") is open on the one surface S1 side and has a bottom 21b on the other surface S2 side. The opening 22 on the other surface S2 side (hereinafter also referred to as the "other surface side opening") is open on the other surface S2 side and has a bottom 22b on the one surface S1 side. In this embodiment, each opening 21, 22 has a substantially cylindrical shape, and the multiple openings 21, 22 have substantially the same shape.

[0016] In the fire-resistant wood composite material of the present invention, the positions of the center points of the one-side openings and the other-side openings in the flame-retardant agent holding plate are offset in the first direction, the second direction, or both. In the fire-resistant wood composite material 1 of this embodiment, as shown in Fig. 2(a), the positions of the center points 21a, 22a of the one-side openings 21 and the other-side openings 22 in the flame-retardant agent holding plate 10 are offset in both the first direction X and the second direction Y. The positions of the one-side openings 21 and the other-side openings 22 in the flame-retardant agent holding plate 10 according to this embodiment will be described in detail below.

[0017] As shown in FIG. 2(a), the first surface side openings 21 are formed at equal intervals in each of the first direction X and the second direction Y. More specifically, the first surface side openings 21 are arranged in a row at a constant interval Py along the second direction Y to form a first first surface side opening row 21R. The first first surface side opening row 21R is arranged in a plurality of rows at intervals in the first direction X. The positions of the center points 21a of the first surface side openings 21 in the second direction Y of the first surface side openings 21 adjacent to each other in the first direction X coincide with each other. The first surface side openings 21 are arranged in a row at a constant interval Px along the first direction X to form a second first surface side opening row 21L. The second first surface side opening row 21L is arranged in a plurality of rows at intervals in the second direction Y. The first surface side apertures 21 constituting the second first surface side aperture row 21L adjacent in the second direction Y have center points 21a of the apertures 21 in the first direction X aligned with each other.

[0018] That is, the first surface openings 21 constituting the first surface opening row 21R adjacent in the first direction X form a second surface opening row 21L arranged in a row at regular intervals along the first direction X. The interval Py between the first surface openings 21 constituting the first surface opening row 21R and the interval Px between the openings 21 constituting the second surface opening row 21L are the same. The "interval Py between the first surface openings 21 constituting the first surface opening row 21R" refers to the distance between the center points 21a of the first surface openings 21 adjacent in the second direction Y, and the "interval Px between the first surface openings 21 constituting the second surface opening row 21L" refers to the distance between the center points 21a of the first surface openings 21 adjacent in the first direction X (see FIG. 2(a)).

[0019] As shown in FIG. 2(a), the other-side openings 22 are formed at equal intervals in each of the first direction X and the second direction Y. More specifically, the other-side openings 22 form a first other-side opening row 22R in which a plurality of the other-side openings 22 are arranged in a row at a constant interval Qy along the second direction Y. The first other-side opening row 22R is arranged in a plurality of rows at intervals in the first direction X. The positions of the center points 22a of the other-side openings 22 in the second direction Y of the other-side openings 22 constituting the first other-side opening row 22R adjacent to each other in the first direction X coincide with each other. The other-side openings 22 form a second other-side opening row 22L in which a plurality of the other-side openings 22 are arranged in a row at a constant interval Qx along the first direction X. The second other-side opening row 22L is arranged in a plurality of rows at intervals in the second direction Y. The other-side apertures 22 constituting the second other-side aperture row 22L adjacent in the second direction Y have center points 22a of the apertures 22 in the first direction X aligned with each other.

[0020] That is, the other surface side apertures 22 constituting the first other surface side aperture row 22R adjacent in the first direction X form a second other surface side aperture row 22L arranged in a row at regular intervals along the first direction X. The interval Qy between the other surface side apertures 22 constituting the first other surface side aperture row 22R and the interval Qx between the apertures 22 constituting the second other surface side aperture row 22L are the same. The "interval Qy between the other surface side apertures 22 constituting the first other surface side aperture row 22R" refers to the distance between the center points 22a of the other surface side apertures 22 adjacent in the second direction Y, and the "interval Qx between the other surface side apertures 22 constituting the second other surface side aperture row 22L" refers to the distance between the center points 22a of the other surface side apertures 22 adjacent in the first direction X (see FIG. 2(a)).

[0021] In the flame retardant agent holding plate 10 according to this embodiment, as described above, the positions of the center points 21a, 22a of the one-side opening 21 and the other-side opening 22 are offset in both the first direction X and the second direction Y. More specifically, the first other-side opening row 22R is disposed between the first one-side opening rows 21R adjacent to each other in the first direction X. The first one-side opening row 21R and the first other-side opening row 22R are offset by half a pitch in the second direction Y. Furthermore, the second other-side opening row 22L is disposed between the second one-side opening rows 21L adjacent to each other in the second direction Y. Furthermore, the second one-side opening row 21L and the second other-side opening row 22L are offset by half a pitch in the first direction X. In the above, the arrangement of the openings 21, 22 in the upper flame-retardant agent holding plate 10 of the two stacked flame-retardant agent holding plates 10 has been described, but the arrangement of the openings 21, 22 in the lower flame-retardant agent holding plate 10 is similar.

[0022] In the fire-resistant wood composite material 1, as shown in Figures 1 and 3, two flame retardant agent holding plates 10 are laminated. In this embodiment, as shown in Figure 3, the openings 21, 22 formed on the opposing surfaces of the flame retardant agent holding plates 10 adjacent to each other in the thickness direction Z do not overlap. Specifically, the opening 22 on the other surface side of the flame retardant agent holding plate 10 does not overlap with the opening 21 on the one surface side of the flame retardant agent holding plate 10 adjacent to the flame retardant agent holding plate 10 in the thickness direction Z.

[0023] In this embodiment, the positional relationship between adjacent flame retardant agent holding plates 10 in the thickness direction Z is not particularly limited, and for example, the openings 21, 22 formed on the opposing surfaces of adjacent flame retardant agent holding plates 10 in the thickness direction Z may completely overlap each other as shown in Fig. 4. Note that the openings 21, 22 formed on the opposing surfaces of adjacent flame retardant agent holding plates 10 in the thickness direction Z may partially overlap each other.

[0024] The fire-resistant wood composite material 1 of this embodiment can be manufactured, for example, as follows. First, the openings 21, 22 are formed in a wood substrate 20 that does not have openings 21, 22, with the positions of the center points 21a, 22a shifted in the first direction X and the second direction Y. Next, the openings 21, 22 are filled with a flame retardant-containing solid material 30. The flame retardant-holding plates 10 thus manufactured are stacked on top of each other to manufacture the fire-resistant wood composite material 1. The stacked flame retardant-holding plates 10 are preferably joined together, for example, with an adhesive or the like.

[0025] The order of forming the openings 21, 22 and the order of filling the openings with the flame retardant agent-containing solid material 30 are not particularly limited. Either one of the openings 21 on the one side and the openings 22 on the other side may be formed after the openings on the other side are formed, or both openings 21, 22 may be formed simultaneously. Also, either one of the openings 21 on the one side and the openings 22 on the other side may be filled with the flame retardant agent-containing solid material 30 after the openings on the other side are filled with the flame retardant agent-containing solid material 30, or both openings 21, 22 may be filled with the flame retardant agent-containing solid material 30 at the same time. Also, either one of the openings 21 on the one side and the openings 22 on the other side may be formed, and then the opening formed may be filled with the flame retardant agent-containing solid material 30, and then the other opening may be formed, and then the opening formed may be filled with the flame retardant agent-containing solid material 30. Details of the manufacturing method of the fire-resistant wood composite material 1 will be described later.

[0026] In the fire-resistant wood composite material 1 of this embodiment, the one-side opening 21 and the other-side opening 22 of the flame-retardant agent holding plate 10 are non-through openings, so that when the openings 21, 22 are filled with the flame-retardant agent-containing solid material 30, the flame-retardant agent-containing solid material 30 is unlikely to pop out of the openings 21, 22. Therefore, when manufacturing the fire-resistant wood composite material 1, there is no need to manually repair the fire-resistant wood composite material 1 during manufacturing, so that the manufacturing process of the fire-resistant wood composite material 1 can be easily implemented in an line.

[0027] As described above, in the fire-resistant wood composite material 1 of this embodiment, the position of the center point 21a of the one-side opening 21 and the position of the center point 22a of the other-side opening 22 in the flame-retardant agent holding plate 10 are offset in both the first direction X and the second direction Y. With this configuration, even if a portion of one side of the fire-resistant wood composite material 1, i.e., a portion of one side S1 of the uppermost flame-retardant agent holding plate 10 among the flame-retardant agent holding plates 10 adjacent in the thickness direction Z, that is not the one-side opening 21, burns and the combustion progresses downward in the thickness direction Z, the other-side opening 22 filled with the flame-retardant agent-containing solid 30 is located below that portion in the thickness direction Z, so that the combustion can be prevented from progressing downward in the thickness direction Z. Therefore, it is not necessarily necessary to stack the flame retardant agent holding plates 10 so that the flame retardant-containing solid material 30 of another flame retardant agent holding plate 10 is located below in the thickness direction Z of the portion of the flame retardant agent holding plate 10 that is not the one-side opening 21. In other words, in the fire-resistant wood composite material 1 of this embodiment, the positional relationship between the stacked flame retardant agent holding plates 10 can be arbitrary, so that it is easy to stack a plurality of flame retardant agent holding plates 10 to form the fire-resistant wood composite material 1. In this manner, the fire-resistant wood composite material 1 of this embodiment can be easily manufactured.

[0028] In addition, in the fire-resistant wood composite material 1 of this embodiment, the positions of the center points 21a, 22a of the one-side opening 21 and the other-side opening 22 of the flame retardant holding plate 10 are in the positional relationship as described above, so that the combustion in the flame retardant holding plate 10 can be prevented from progressing downward in the thickness direction Z. Therefore, even if the number of flame retardant holding plates 10 in the fire-resistant wood composite material 1 is small, the fire resistance of the fire-resistant wood composite material 1 can be maintained. However, the number of flame retardant holding plates 10 in the fire-resistant wood composite material 1 is not particularly limited. In this embodiment, two flame retardant holding plates 10 are stacked, but three or more flame retardant holding plates 10 may be stacked. For example, two to four flame retardant holding plates 10 may be stacked. In addition, in the fire-resistant wood composite material 1 of this embodiment, as described above, the one-side opening 21 and the other-side opening 22 of the flame retardant agent holding plate 10 are non-through. Therefore, for example, it is not necessary to provide a sealing layer on the one side S1 side or the other side S2 side of the wood base material 20 for the purpose of preventing the flame retardant agent-containing solid 30 from falling out of the one-side opening 21 or the other-side opening 22. Therefore, it is possible to prevent the thickness of the flame retardant agent holding plate 10 from becoming thicker than the thickness of the wood base material 20. Therefore, it is possible to prevent the fire-resistant wood composite material 1 in which the flame retardant agent holding plate 10 is laminated from becoming thicker. In this way, the fire-resistant wood composite material 1 of this embodiment is able to achieve both thinness and fire resistance.

[0029] The flame retardant agent holding plate 10 used in the fire-resistant wood composite material 1 has a first surface opening 21 and a second surface opening 22 that are non-through holes, so that the flame retardant agent-containing solid material 30 is less likely to pop out when filled with the flame retardant agent-containing solid material 30, and is easy to manufacture. In addition, whether used as a single layer or in a laminated form, it is easy to achieve both thinness and fire resistance.

[0030] 2(b), the flame retardant agent holding plate 10 according to this embodiment has an aperture overlap region 25 in its thickness direction Z where both a part of the one surface side aperture 21 and a part of the other surface side aperture 22 are present. In other words, in the thickness direction Z, the position of the bottom 21b of the one surface side aperture 21 is located closer to the other surface S2 side of the flame retardant agent holding plate 10 than the position of the bottom 22b of the other surface side aperture 22. More specifically, the total depth (H1+H2) of the depth H1 of the one surface side aperture 21 and the depth H2 of the other surface side aperture 22 of the flame retardant agent holding plate 10 is greater than the thickness H of the flame retardant agent holding plate 10.

[0031] As shown in FIG. 2(b), the flame retardant agent holding plate 10 preferably has an aperture overlap region 25 in the central region 10C in the thickness direction Z. This can further improve the fire resistance of the flame retardant agent holding plate 10, and therefore the fire resistance of the fire-resistant wood composite material 1. In order to achieve this effect more significantly, the ratio H3 / H of the length H3 in the thickness direction Z of the aperture overlap region 25 to the thickness H of the flame retardant agent holding plate 10 is preferably 0.04 or more, more preferably 0.08 or more. The upper limit of the ratio H3 / H can be set to, for example, 0.8. The length H3 in the thickness direction Z of the aperture overlap region 25 can be calculated by subtracting the thickness H of the flame retardant agent holding plate 10 from the total depth (H1+H2) of the depth H1 of the one-side aperture 21 and the depth H2 of the other-side aperture 22.

[0032] It is preferable that the ratio H3 / H is within the above-mentioned range in at least one of the multiple flame retardant chemical holding plates 10 contained in the fire-resistant wood composite 1, and it is more preferable that the ratio H3 / H is within the above-mentioned range in all of the multiple flame retardant chemical holding plates 10. The central region 10C of the flame-retardant agent holding plate 10 can be, for example, the two central regions when the flame-retardant agent holding plate 10 is divided into four equal regions in the thickness direction Z, as shown in FIG. 2(b).

[0033] The ratio H1 / H of the depth H1 of the one-side opening 21 to the thickness H of the flame retardant agent holding plate 10 is preferably 0.3 to 0.9, more preferably 0.5 to 0.8. The depth H1 of the one-side opening 21 means the depth of the deepest part of the one-side opening 21. It is preferable that the ratio H1 / H is within the above-mentioned range in at least one of the multiple flame retardant agent holding plates 10 in the fire-resistant wood composite material 1, and it is more preferable that the ratio H1 / H is within the above-mentioned range in all of the multiple flame retardant agent holding plates 10.

[0034] The ratio H2 / H of the depth H2 of the other-side opening 22 to the thickness H of the flame-retardant agent holding plate 10 is preferably 0.3 to 0.9, more preferably 0.5 to 0.8. The depth H2 of the other-side opening 22 means the depth of the deepest part of the other-side opening 22. It is preferable that the ratio H2 / H is within the above-mentioned range in at least one of the multiple flame-retardant agent holding plates 10 in the fire-resistant wood composite material 1, and it is more preferable that the ratio H2 / H is within the above-mentioned range in all of the multiple flame-retardant agent holding plates 10. The ratio H1 / H and the ratio H2 / H may be the same or different.

[0035] The thickness H of the flame retardant agent holding plate 10 is preferably 12 mm to 48 mm, more preferably 18 mm to 30 mm. It is preferable that at least one of the flame retardant agent holding plates 10 in the fire-resistant wood composite material 1 has a thickness H within the above range, and it is more preferable that all of the flame retardant agent holding plates 10 have a thickness H within the above range.

[0036] In the flame retardant chemical holding plate 10, the one surface opening 21 and the other surface opening 22 may overlap partially with each other when viewed in a plane of the flame retardant chemical holding plate 10, or they may not overlap as shown in Figure 2(a). In the flame retardant agent holding plate 10, it is preferable that 50% to 100% of the first surface openings 21 do not overlap with the other surface openings 22, it is more preferable that 70% to 100% of the first surface openings 21 do not overlap with the other surface openings 22, and it is even more preferable that 90% to 100% of the first surface openings 21 do not overlap with the other surface openings 22. It is preferable that in at least one of the multiple flame retardant agent holding plates 10 in the fire-resistant wood composite material 1, the proportion of the first surface openings 21 that do not overlap with the other surface openings 22 is within the above-mentioned range, and it is more preferable that in all of the multiple flame retardant agent holding plates 10, the proportion of the first surface openings 21 that do not overlap with the other surface openings 22 is within the above-mentioned range.

[0037] In the flame retardant holding plate 10, the total opening area of ​​the one-side openings 21 is preferably 9% or more, more preferably 11% or more, more preferably 30% or less, more preferably 22% or less, preferably 9% or more and 30% or less, and more preferably 11% or more and 22% or less, relative to the area of ​​one surface S1 of the wood substrate 20, from the viewpoint of holding a necessary amount of the flame retardant-containing solid 30. It is preferable that in at least one of the flame retardant holding plates 10 of the fire-resistant wood composite material 1, the ratio of the total opening area of ​​the one-side openings 21 to the area of ​​one surface S1 of the wood substrate 20 is within the above-mentioned range, and it is more preferable that in all of the flame retardant holding plates 10, the ratio of the total opening area of ​​the one-side openings 21 to the area of ​​the one surface S1 is within the above-mentioned range.

[0038] In the flame retardant holding plate 10, the total opening area of ​​the other side openings 22 is preferably 9% or more, more preferably 11% or more, more preferably 30% or less, more preferably 22% or less, preferably 9% or more and 30% or less, and more preferably 11% or more and 22% or less, relative to the area of ​​the other side S2 of the wood substrate 20, from the viewpoint of holding a necessary amount of the flame retardant-containing solid 30. It is preferable that in at least one of the flame retardant holding plates 10 of the fire-resistant wood composite material 1, the ratio of the total opening area of ​​the other side openings 22 to the area of ​​the other side S2 of the wood substrate 20 is within the above-mentioned range, and it is more preferable that in all of the flame retardant holding plates 10, the ratio of the total opening area of ​​the other side openings 22 to the other side S2 is within the above-mentioned range. The ratio of the total opening area of ​​the one-surface-side holes 21 to the one surface S1 and the ratio of the total opening area of ​​the other-surface-side holes 22 to the other surface S2 may be the same or different.

[0039] From the viewpoints of holding the necessary amount of flame retardant-containing solid 30 and preventing large cracks from occurring during a heating test by cutting the edges, the diameter of one-side opening 21 is preferably 6 mm or more, more preferably 7 mm or more, preferably 12 mm or less, more preferably 11 mm or less, preferably 6 mm or more and 12 mm or less, and more preferably 7 mm or more and 11 mm or less. It is preferable that the diameter of one-side opening 21 in at least one of the multiple flame retardant holding plates 10 in fire-resistant wood composite material 1 is within the above-mentioned range, and it is more preferable that the diameter of one-side opening 21 in all of the multiple flame retardant holding plates 10 is within the above-mentioned range.

[0040] From the viewpoints of holding the necessary amount of flame retardant-containing solid 30 and preventing large cracks from occurring during a heating test by cutting the edges, the diameter of the other side opening 22 is preferably 6 mm or more, more preferably 7 mm or more, preferably 12 mm or less, more preferably 11 mm or less, preferably 6 mm or more and 12 mm or less, and more preferably 7 mm or more and 11 mm or less. It is preferable that the diameter of the other side opening 22 in at least one of the multiple flame retardant holding plates 10 in the fire-resistant wood composite material 1 is within the above-mentioned range, and it is more preferable that the diameter of the other side opening 22 in all of the multiple flame retardant holding plates 10 is within the above-mentioned range. The diameter of the one surface side opening 21 and the diameter of the other surface side opening 22 may be the same or different.

[0041] The flame retardant agent-containing solid 30 may be of the same shape and size as the first surface opening 21 and the second surface opening 22, respectively, or may have smaller dimensions than the first surface opening 21 and the second surface opening 22, respectively. More specifically, the volume of the flame retardant-containing solid 30 filled in the one-side opening 21 relative to the volume of the opening 21 is preferably 70% or more, more preferably 90% or more, with the upper limit being 100%. It is preferable that the volume of the flame retardant-containing solid 30 filled in the one-side opening 21 relative to the volume of the opening 21 in at least one of the multiple flame retardant-holding plates 10 in the fire-resistant wood composite material 1 is within the above-mentioned range, and it is more preferable that the volume of the flame retardant-containing solid 30 filled in the one-side opening 21 relative to the volume of the opening 21 in all of the multiple flame retardant-holding plates 10 is within the above-mentioned range.

[0042] The volume of the flame retardant-containing solid 30 filled in the other-side opening 22 relative to the volume of the opening 22 is preferably 70% or more, more preferably 90% or more, with the upper limit being 100%. It is preferable that the volume of the flame retardant-containing solid 30 filled in the other-side opening 22 relative to the volume of the opening 22 in at least one of the multiple flame retardant-containing holding plates 10 in the fire-resistant wood composite material 1 is within the above-mentioned range, and it is more preferable that the volume of the flame retardant-containing solid 30 filled in the other-side opening 22 relative to the volume of the opening 22 in all of the multiple flame retardant-containing holding plates 10 is within the above-mentioned range.

[0043] From the viewpoints of holding the necessary amount of flame retardant-containing solid material 30 and preventing large cracks from occurring during a heating test by cutting the edges, the intervals Py and Px of the first side openings 21 constituting the first first side opening row 21R and the second first side opening row 21L are preferably 15 mm or more, more preferably 18 mm or more, and preferably 30 mm or less, more preferably 25 mm or less, preferably 15 mm or more and 30 mm or less, and more preferably 18 mm or more and 25 mm or less (see FIG. 2(a)). It is preferable that the intervals Py and Px of the first side openings 21 in at least one of the multiple flame retardant holding plates 10 in the fire-resistant wood composite material 1 are within the above-mentioned range, and it is more preferable that the intervals Py and Px of the first side openings 21 in all of the multiple flame retardant holding plates 10 are within the above-mentioned range.

[0044] From the viewpoints of holding a necessary amount of the flame retardant-containing solid 30 and preventing large cracks from occurring during a heating test by cutting the edges, the intervals Qy and Qx of the other side openings 22 constituting the first other side opening row 22R and the second other side opening row 22L are preferably 15 mm or more, more preferably 18 mm or more, and preferably 30 mm or less, more preferably 25 mm or less, preferably 15 mm or more and 30 mm or less, and more preferably 18 mm or more and 25 mm or less (see FIG. 2(a)). It is preferable that the intervals Qy and Qx of the other side openings 22 in at least one of the multiple flame retardant holding plates 10 of the fire-resistant wood composite material 1 are within the above-mentioned range, and it is more preferable that the intervals Qy and Qx of the other side openings 22 in all of the multiple flame retardant holding plates 10 are within the above-mentioned range.

[0045] In this embodiment, the one-surface side openings 21 are formed at equal intervals in each of the first direction X and the second direction Y, but the spacing Py of the one-surface side openings 21 constituting the first one-surface side opening row 21R and the spacing Px of the one-surface side openings 21 constituting the second one-surface side opening row 21L may be different. When the interval Py of the first side openings 21 constituting the first one-side opening row 21R is different from the interval Px of the first side openings 21 constituting the second one-side opening row 21L, the interval Px of the first side openings 21 constituting the second one-side opening row 21L is preferably 15 mm or more, more preferably 18 mm or more, preferably 50 mm or less, more preferably 25 mm or less, preferably 15 mm or more and 50 mm or less, and more preferably 18 mm or more and 25 mm or less from the viewpoint of preventing an extreme decrease in the strength of the flame retardant agent holding plate 10 itself in one direction and ensuring homogeneity in agent holding (see FIG. 2(a)). It is preferable that the interval Px of the first side openings 21 of at least the multiple flame retardant agent holding plates 10 of the fire-resistant wood composite material 1 is within the above-mentioned range, and it is more preferable that the interval Px of the first side openings 21 of all the multiple flame retardant agent holding plates 10 is within the above-mentioned range.

[0046] In addition, in this embodiment, the other-side openings 22 are formed at equal intervals in each of the first direction X and the second direction Y, but the interval Qy of the other-side openings 22 constituting the first other-side opening row 22R and the interval Qx of the other-side openings 22 constituting the second other-side opening row 22L may be different. When the interval Qy of the other side openings 22 constituting the first other side opening row 22R is different from the interval Qx of the other side openings 22 constituting the second other side opening row 22L, the interval Qx of the other side openings 22 constituting the second other side opening row 22L is preferably 15 mm or more, more preferably 18 mm or more, preferably 50 mm or less, more preferably 25 mm or less, preferably 15 mm or more and 50 mm or less, and more preferably 18 mm or more and 25 mm or less (see FIG. 2(a)) from the viewpoint of preventing an extreme decrease in the strength of the flame retardant agent holding plate 10 itself in one direction and ensuring homogeneity in agent holding. It is preferable that the interval Qx of the other side openings 22 of at least the multiple flame retardant agent holding plates 10 of the fire-resistant wood composite material 1 is within the above-mentioned range, and it is more preferable that the interval Qx of the other side openings 22 of all the multiple flame retardant agent holding plates 10 is within the above-mentioned range.

[0047] In the fire-resistant wood composite material 1 of this embodiment, as shown in Fig. 3, nothing is arranged on the outer surface side of the flame retardant chemical holding plates 10 located at both ends in the thickness direction Z, but as shown in Fig. 4, a decorative layer 5 may be arranged on the side opposite to the side where another flame retardant chemical holding plate 10 is present in at least one of the flame retardant chemical holding plates 10 located at both ends in the thickness direction Z. Specifically, it is preferable that the decorative layer 5 constitutes the surface of the fire-resistant wood composite material 1 that is heated from the outside in the event of a fire. As the decorative layer 5, a decorative sheet made of a veneer, synthetic resin, paper, etc., as well as a coating layer, etc. can be used. By arranging a decorative layer 5 on the side opposite to the side on which another flame retardant chemical holding plate 10 is present in at least one of the flame retardant chemical holding plates 10 located at both ends in the thickness direction Z, it is possible to improve the design of the fire-resistant wood composite material 1. The flame-retardant agent holding plates 10 located at both ends in the thickness direction Z are the flame-retardant agent holding plates located at the ends or closest to the ends in the thickness direction Z among the multiple flame-retardant agent holding plates 10.

[0048] At least one of the flame retardant holding plates 10 located at both ends in the thickness direction Z may have a flame retardant applied to a surface S1 opposite to the side where another flame retardant holding plate 10 is present. Specifically, it is preferable that the flame retardant is applied to a surface of the fire-resistant wood composite material 1 that constitutes the side that is heated from the outside in the event of a fire. When the fire-resistant wood composite material 1 has a decorative layer 5, the flame retardant may be applied to a surface of the decorative layer 5 opposite to the flame retardant holding plate 10. Also, the flame retardant may be disposed between the decorative layer 5 and the flame retardant holding plate 10 by a method such as applying the flame retardant to one or both of the decorative layer 5 and the flame retardant holding plate 10. The flame retardant applied to the decorative layer 5 or the flame retardant holding plate 10 may be the same as the solid flame retardant contained in the flame retardant-containing solid material 30, or may be different. By applying a flame retardant agent to the surface constituting the outer side of the fire-resistant wood composite material 1, it is possible to further improve the fire resistance of the fire-resistant wood composite material 1.

[0049] Next, the constituent materials of the fire-resistant wood composite material 1 of this embodiment will be described. The wooden substrate 20 is made of a laminate of multiple veneers or boards. When the wooden substrate 20 is made of a laminate of veneers, the laminate may contain multiple types of veneers with different fiber orientation directions, or may be made of only veneers with the same fiber orientation direction, such as laminated veneer lumber (LVL). Instead of being made of a laminate of multiple veneers, the wooden substrate 20 may be made of a single board that is a non-laminated material. The species of wood constituting the wood substrate 20, for example the raw wood of the veneer, may be a conifer or a broadleaf tree, such as oak, teak, walnut, falcata, balsa, red lauan, ash, elm, birch, paulownia, cedar, cypress, larch, Ezo spruce, Todomatsu, Akamatsu, Hiba, whitewood, European scotch pine, Dahurica larch, Douglas fir, etc. The species of raw wood may be one or a laminate of two or more species selected from the above-mentioned tree species, and may be used as the wood substrate 20. Among these, from the viewpoints of reducing the amount of heat generated during combustion and being easy to secure as a raw material for veneers, it is preferable to use coniferous trees such as cedar and todomatsu, which are relatively light and easy to secure as raw materials. From the same viewpoint, it is also preferable to use wood species having an air-dry density of 0.3 to 0.6 g / cm. 3 It is preferable to use a material having an air-dry density of 0.4 to 0.5 g / cm. 3 It is more preferable to use one in which the air-dry density is determined by the average value of a plurality of veneer laminates.

[0050] The flame retardant-containing solid 30 is a solid in a solid state. The flame retardant-containing solid 30 may be a cured product or a compressed powder. The flame retardant-containing solid 30 is preferably water resistant. In order to impart water resistance and other properties to the flame retardant-containing solid 30, the surface of the flame retardant-containing solid 30 may be coated with a material having a function of imparting water resistance, such as an acrylic resin, a urethane resin, a urethane acrylic resin, an alkyd resin, a polyester resin, a silicone-modified polyester resin, a silicone-modified acrylic resin, an epoxy resin, a polycarbonate resin, a silicate resin, a fluororesin, a chlorine-based resin, or a polyolefin resin. Commercially available products such as a solventless moisture-curing silicone coating composition (KR-400, manufactured by Shin-Etsu Chemical Co., Ltd.) may also be used.

[0051] The cured product is a product of curing a curable composition containing a solid flame retardant. In the production stage of the fire-resistant wood composite material 1, a paste-like curable composition may be filled in the openings 21, 22 in a fluid state and then cured to form a cured product, or a paste-like curable composition may be cured to form a cured product and then the cured product may be filled into the openings 21, 22. The curable composition is cured under a predetermined condition or operation. Such a curable composition includes a component that is cured under a predetermined condition or operation. Examples of the predetermined condition or operation include room temperature curing, moisture curing, heat curing at 40 to 150°C, and curing by chemical reaction in the presence of a catalyst. In addition, a conductor such as iron powder may be added to the curable composition and cured by high-frequency heating. In addition, the curable composition may be in the form of a fluid containing a solvent at the manufacturing stage. In this case, the solvent is volatilized by the passage of time or heating, and the curable composition can be made into a cured product. An organic solvent or the like can be used as the solvent.

[0052] The room temperature curing component is a component that cures by being left at room temperature in the atmosphere, and examples thereof include oxidation curing paints and moisture curing paints. The oxidation curing component is a component that cures by oxidation polymerization via oxygen in the atmosphere, and examples thereof include paints containing hydrocarbon compounds having unsaturated bonds. The moisture curing component is a component that cures by reacting with moisture in the atmosphere, and examples thereof include silicone-based paints having alkoxy groups or silanol groups. The 40 to 150°C heat curing component is a component that cures by heating to 40 to 150°C, and examples thereof include urethane-based paints that cure by the reaction of hydroxyl groups with blocked isocyanates, and epoxy-based paints that cure by the reaction of epoxy groups or ring-opening polymerization.

[0053] The cured product of the present invention may contain a curing catalyst for the purpose of promoting the curing reaction, and the type, mixing amount, addition method, etc. of the curing catalyst can be determined by known methods and conditions according to the type of composition. When the curable composition contains a component that cures by a chemical reaction in the presence of a catalyst, the curable composition preferably contains a curing catalyst. Examples of the curing catalyst include basic compounds such as lithium hydroxide, sodium hydroxide, potassium hydroxide, sodium methylate, sodium propionate, potassium propionate, sodium acetate, potassium acetate, sodium formate, potassium formate, trimethylbenzylammonium hydroxide, tetramethylammonium hydroxide, tetramethylammonium acetate, n-hexylamine, tributylamine, diazabicycloundecene (DBU), and dicyandiamide; metal-containing compounds such as tetraisopropyl titanate, tetrabutyl titanate, titanium acetylacetonate, aluminum triisobutoxide, aluminum triisopropoxide, tris(acetylacetonate)aluminum, diisopropoxy(ethylacetoacetate)aluminum, aluminum perchlorate, aluminum chloride, cobalt octylate, cobalt acetylacetonate, iron acetylacetonate, tin acetylacetonate, dibutyltin octylate, and dibutyltin laurate; and acidic compounds such as p-toluenesulfonic acid and trichloroacetic acid. Among these, in particular, sodium propionate, sodium acetate, sodium formate, trimethylbenzylammonium hydroxide, tetramethylammonium hydroxide, tris(acetylacetonate)aluminum, diisopropoxy(ethylacetoacetate)aluminum, etc. are mentioned, and among these, metal-containing compounds such as aluminum catalysts containing organic ligands and titanium catalysts containing organic ligands are preferred.

[0054] In this embodiment, it is preferable that the curable compound is contained as the curable component. The curable compound is a compound that is cured under a predetermined condition or operation. Examples of the predetermined condition or operation include those described above. Examples of the curable compound include moisture-curable or heat-curable coating compositions containing resin components such as acrylic resin, urethane resin, urethane acrylic resin, alkyd resin, polyester resin, silicone-modified polyester resin, silicone-modified acrylic resin, epoxy resin, polycarbonate resin, silicate resin, fluororesin, chlorine-based resin, and polyolefin resin.

[0055] The curable compound is preferably a compound represented by the following general formula (1) or a hydrolysis condensate thereof, or both. SiR 1 (4-n) R 2 n (1) (In the formula, each R1 independently represents a hydrogen atom, or an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, which may be substituted with one or more of an amino group, an epoxy group, an acid anhydride group, a maleimide group, a vinyl group, an allyl group, an acryl group, a methacryl group, or a heterocyclic group; each R2 independently represents a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, or a halogen atom; and n represents an integer of 1 to 4.) The n is preferably 3. A part or all of the R1 is preferably an alkyl group having 6 to 20 carbon atoms. It is also preferable that a part or all of the R1 is an alkyl group having 1 to 20 carbon atoms substituted with one or more epoxy groups.

[0056] From the viewpoints of dispersion of the flame retardant agent, ease of handling of the curable compound, formation of a charred layer after combustion, and improvement of water resistance, it is preferable that 50 mass% or more of the curable compound is a compound represented by the above formula (1), more preferably 70 mass% or more of the curable compound is a compound represented by the above formula (1), and even more preferably 90 mass% or more of the curable compound is a compound represented by the above formula (1).

[0057] As described above, the curable composition contains a solid flame retardant agent. In this embodiment, the curable composition contains a component that is cured under a predetermined condition or operation, and the content of the solid flame retardant agent is preferably 90 mass% or less. The preferred range of the content of the solid flame retardant agent in the curable composition will be described later.

[0058] A solid flame retardant is a chemical agent having flame retardancy. Examples of solid flame retardants include phosphorus compounds and boron compounds. Examples of phosphorus compounds include organic phosphorus compounds, phosphoric acid, phosphoric acid esters, and phosphates, and specific examples thereof include diammonium hydrogen phosphate, ammonium dihydrogen phosphate, diguanidine phosphate, ammonium polyphosphate, hydrophobized ammonium polyphosphate, and guanylurea phosphate. Examples of boron compounds include organic boron compounds, boric acid, borax, boron oxide, boric acid esters, and borate salts. Examples of compounds other than phosphorus compounds and boron compounds include ammonium sulfate and zinc chloride. Among these, it is preferable that the solid flame retardant is one or more selected from the group consisting of organic phosphorus compounds, phosphoric acid, phosphoric acid esters, phosphate salts, organic boron compounds, boric acid, boric acid esters, and borates, and more preferably boric acid. The solid flame retardant component may be used alone or in combination of two or more.

[0059] The green compact is obtained by compacting a powder. In this embodiment, from the viewpoint of facilitating the formation of the green compact by compaction, it is preferable to compact the powder in a state where the powder and a binder are mixed. The powder according to this embodiment contains a solid flame retardant. As the binder, a known binder used for forming a green compact can be used, and examples of the binder include resin components such as polyvinyl alcohol resin, acrylic resin, urethane resin, urethane acrylic resin, alkyd resin, polyester resin, silicone-modified polyester resin, silicone-modified acrylic resin, epoxy resin, polycarbonate resin, silicate resin, fluororesin, chlorine-based resin, and polyolefin resin. In addition, a curable composition can be used as the binder.

[0060] As described above, the green compact contains a solid flame retardant. In this embodiment, the green compact is obtained by compacting a powder, and the content of the solid flame retardant is preferably 80 mass % or more. The preferred range of the content of the solid flame retardant in the green compact will be described later.

[0061] The amount of flame retardant-containing solid matter 30 held per unit volume of the flame retardant agent holding plate 10 is set to 90 kg / m from the viewpoints of ensuring the strength of the flame retardant agent holding plate 10 itself, improving the heat absorbing performance during combustion, and maintaining the carbonized heat insulating layer. 3 It is preferable that the density is 100 kg / m or more. 3 More preferably, it is 270 kg / m or more. 3 It is preferable that the thickness is less than 200 kg / m 3 More preferably, it is 90 kg / m or less. 3 More than 270kg / m 3 It is preferable that the density is less than 100 kg / m 3 More than 200kg / m 3 It is more preferable that the amount of flame retardant-containing solid material 30 held per unit volume in at least one of the multiple flame retardant-containing solid material plates 10 in the fire-resistant wood composite material 1 is within the above-mentioned range, and it is even more preferable that the amount of flame retardant-containing solid material 30 held per unit volume in all of the multiple flame retardant-containing solid material plates 10 is within the above-mentioned range.

[0062] By using a solid material in a solid state as the flame retardant-containing solid material 30, it becomes easier to prevent uneven impregnation of the flame retardant and uneven content of the flame retardant during drying, and it becomes easier to make the content of the flame retardant in the flame retardant holding plate 10 uniform and to make the content of the solid flame retardant in the flame retardant holding plate 10 a desired amount, so it becomes possible to stably ensure fire resistance. Conventionally, as a technique for imparting fire resistance to wood, a method is known in which a flame retardant dissolved in water is impregnated into wood and then the wood is dried. However, with this method, uneven impregnation of the flame retardant occurs during impregnation, and the content of the flame retardant on the surface side of the wood becomes higher than the inside of the wood during drying, resulting in uneven content of the flame retardant throughout the wood, making it difficult to stably ensure fire resistance in wood.

[0063] In addition, in this embodiment, a hardened product or a compressed powder is used as the flame retardant-containing solid material 30, which is a solid material, so that even if the fire-resistant wood composite material 1 gets wet with water, the flame retardant is less likely to dissolve, making it possible to improve water resistance.

[0064] From the viewpoint of improving the fire resistance of the fire-resistant wood composite material 1, the curable composition preferably contains the solid flame retardant in the range of 50 to 90 mass%, more preferably in the range of 60 to 85 mass%, and even more preferably in the range of 65 to 80 mass%. From the same viewpoint, the green compact preferably contains the solid flame retardant in the range of 80 mass% or more, more preferably in the range of 90 mass% or more, and even more preferably in the range of 95 mass% or more. The green compact may be composed only of the solid flame retardant, that is, may contain 100 mass% of the solid flame retardant agent, but if it is 100 mass%, the amount of binder used will be reduced, which may make it difficult to set the conditions for compression molding, so that it is preferably 99 mass% or less, more preferably 97 mass% or less.

[0065] Next, a method for producing the fire-resistant wood composite material 1 of this embodiment will be described. First, the production of a fire-resistant wood composite material 1 having a cured material as the flame-retardant agent-containing solid material 30 will be described. First, the openings 21, 22 are formed in the wood substrate 20 where the openings 21, 22 are not formed, with the positions of the center points 21a, 22a shifted in the first direction X and the second direction Y. Separately, the hardening composition is placed in a container having substantially the same shape as the openings 21, 22, and the hardening composition is hardened in the container. In this way, the hardened product, the flame retardant-containing solid 30, is obtained. Next, the openings 21, 22 are filled with the flame retardant-containing solid 30. Prior to filling the openings 21, 22 with the flame retardant-containing solid 30, an adhesive may be applied to the surface of the flame retardant-containing solid 30 or to the periphery of the openings 21, 22. This makes it possible to prevent the flame retardant-containing solid 30 from slipping out of the openings 21, 22. In this way, the flame retardant-containing plate 10 is manufactured. The flame retardant-containing plates 10 manufactured in this way are stacked together to manufacture the fire-resistant wood composite material 1.

[0066] The method of curing the curable composition is not particularly limited. The method of curing the curable composition includes, for example, a method of curing under the above-mentioned predetermined conditions or operations. For example, the curable composition may be cured by adding a curing catalyst to a container containing the curable composition and causing a chemical reaction, or the curable composition may be cured by leaving the curable composition in the container and reacting the curing catalyst with moisture in the air, or the curable composition may be cured by heating the container containing the curable composition.

[0067] The adhesive to be applied to the surface of the flame retardant-containing solid material 30 or to the peripheral surfaces of the openings 21, 22 may be any of various known adhesives conventionally used in the manufacture of wood composite materials, such as hot melt adhesives, vinyl acetate adhesives, epoxy adhesives, etc. Among these, it is preferable to use a vinyl acetate adhesive. The flame retardant agent holding plates 10 can be bonded together using various known adhesives that have been conventionally used in the manufacture of wood composite materials, such as aqueous polymer-isocyanate adhesives, resorcinol resin adhesives, resorcinol-phenol resin adhesives, melamine resin adhesives, melamine urea resin adhesives, urethane resin adhesives, epoxy resin adhesives, etc. Among these, resorcinol resin adhesives or resorcinol-phenol resin adhesives are preferred.

[0068] The fire-resistant wood composite material 1 can also be produced as follows. First, the openings 21, 22 are formed in the wood substrate 20 where the openings 21, 22 are not formed, with the positions of the center points 21a, 22a shifted in the first direction X and the second direction Y. Then, the openings 21, 22 are filled with a hardening composition. The hardening composition is hardened to form a hardened product, that is, a flame retardant agent-containing solid material 30, to produce the flame retardant agent-holding plate 10. The flame retardant agent-holding plates 10 thus produced are laminated to produce the fire-resistant wood composite material 1. The openings 21, 22 are both non-through and have bottoms 21b, 22b, so that even if the flame retardant agent-containing solid material 30 is in a liquid state when filled, the flame retardant agent-containing solid material 30 can be easily filled into the openings 21, 22. There is no particular limitation on the method for hardening the hardening composition, and the above-mentioned methods can be used.

[0069] In the above-mentioned manufacturing method, the case where a wood base material 20 in which the openings 21, 22 are not formed is described, however, a wood base material 20 in which the openings 21, 22 are formed in advance in a separate process may also be used.

[0070] Next, a method for producing a fire-resistant wood composite material 1 having a compressed powder as the flame-retardant agent-containing solid material 30 will be described. First, the openings 21, 22 are formed in a wood substrate 20 that does not have the openings 21, 22, with the positions of the center points 21a, 22a shifted in the first direction X and the second direction Y. Separately, a powder containing a solid flame retardant is compacted into a shape substantially identical to the openings 21, 22 to obtain a compacted powder body, that is, a flame retardant-containing solid material 30. Thereafter, the openings 21, 22 are filled with the flame retardant-containing solid material 30 to produce a flame retardant-containing plate 10, in the same manner as when a cured product is used as the flame retardant-containing solid material 30, and the flame retardant-containing plates 10 are laminated together to produce a fire-resistant wood composite material 1.

[0071] The fire-resistant wood composite material 1 can also be produced as follows. First, the openings 21, 22 are formed in a wood substrate 20 that does not have openings 21, 22 formed therein, with the positions of the center points 21a, 22a shifted in the first direction X and the second direction Y. Then, powder containing a solid flame retardant is filled into the openings 21, 22. The powder filled into the openings 21, 22 is then compacted and molded into a flame retardant-containing solid material 30 that is a compact, thereby producing the flame retardant holding plate 10. Thereafter, the flame retardant holding plates 10 are stacked on top of each other to produce the fire-resistant wood composite material 1.

[0072] When a compressed powder is used as the flame retardant agent-containing solid material 30, a wood base material 20 in which the openings 21, 22 have been formed in advance in a separate process may also be used.

[0073] In the above-mentioned manufacturing method, when the flame retardant-containing solid is a cured product, the curable composition is placed in a container having approximately the same shape as the openings 21 and 22, and the curable composition is cured in the container to form the cured product, the flame retardant-containing solid 30. Alternatively, the curable composition may be placed in a cylindrical container having approximately the same diameter as the openings 21 and 22, and a cured product longer than the depth of the openings 21 and 22 is formed, and then the cured product is cut to match the depth of the openings 21 and 22 to form the flame retardant-containing solid 30. A tapioca straw is preferable as the cylindrical container.

[0074] The curable composition may contain other components in addition to the solid flame retardant, the curable composition, and the curing catalyst, as long as the effects of the present invention are not impaired. Examples of other components contained in the curable composition include an ultraviolet absorber, an anti-termite agent, and an antioxidant. The green compact may contain other components in addition to the solid flame retardant, the curable composition, and the curing catalyst, as long as the effects of the present invention are not impaired. Examples of other components contained in the green compact include an ultraviolet absorber, an anti-termite agent, and an antioxidant.

[0075] Furthermore, when the fire-resistant wood composite material 1 has a plurality of flame-retardant-containing solids 30, all of the flame-retardant-containing solids 30 may be cured products or compacts, or some of the plurality of flame-retardant-containing solids 30 may be cured products and the rest may be compacts. A fire-resistant wood composite material in which some of the plurality of flame-retardant-containing solids 30 are cured products and the rest are compacts can be manufactured, for example, as follows.

[0076] First, the openings 21, 22 are formed in the wood base material 20 where the openings 21, 22 are not formed, with the positions of the center points 21a, 22a shifted in the first direction X and the second direction Y. Separately, a hardening composition is placed in a container having a shape substantially the same as the opening 21, and the hardening composition is hardened in the container to obtain a hardened product, a flame retardant-containing solid material 30. In addition, a powder containing a solid flame retardant is compacted into a shape substantially the same as the openings 21, 22 to obtain a compacted product, a flame retardant-containing solid material 30. Next, the hardened product, a flame retardant-containing solid material 30, or a compacted product, a flame retardant-containing solid material 30, is filled into each of the multiple openings 21, 22. In this way, a flame retardant-containing solid material 30 having both a hardened product, a flame retardant-containing solid material 30, and a compacted product, a flame retardant-containing solid material 30, is manufactured. The flame retardant-containing solid material 1 manufactured in this way is laminated on top of each other to manufacture a fire-resistant wood composite material 1.

[0077] It is also possible to manufacture a fire-resistant wood composite material in which a portion of the multiple flame-retardant agent-containing solids 30 are hardened bodies and the remainder are green compacts, as described below. First, the openings 21, 22 are formed in the wood substrate 20 where the openings 21, 22 are not formed, with the positions of the center points 21a, 22a shifted in the first direction X and the second direction Y. Then, the multiple openings 21, 22 are filled with a curable composition or a powder. Then, the curable composition is cured to form a flame retardant-containing solid 30, which is a cured product. The powder is also compacted to form a flame retardant-containing solid 30, which is a compact. In this way, a flame retardant-containing plate 10 is manufactured that has both the flame retardant-containing solid 30, which is a cured product, and the flame retardant-containing solid 30, which is a compact. The flame retardant-containing plates 10 manufactured in this way are stacked together to manufacture a fire-resistant wood composite material 1.

[0078] The flame retardant holding plate 10 in the fire-resistant wood composite material 1 of this embodiment can be laminated in multiple layers and used as the fire-resistant wood composite material 1, or one flame retardant holding plate 10 can be used alone. The flame retardant holding plate 10 is separated by the flame retardant-containing solid material 30 filled in the openings 21 of the wood base material 20, so that the flame retardant holding plate 10 is less likely to crack significantly when the flame retardant holding plate 10 is burned, for example. In addition, by using a solid material in a solid state as the flame retardant-containing solid material 30, the content of the flame retardant in the flame retardant holding plate 10 can be made uniform and the content of the flame retardant in the flame retardant holding plate 10 can be made to a desired amount, so that the fire resistance can be stably guaranteed.

[0079] Moreover, since the one-side opening 21 and the other-side opening 22 of the flame retardant agent holding plate 10 are non-through openings, when the flame retardant agent-containing solid material 30 is filled into the openings 21, 22, the flame retardant agent-containing solid material 30 is unlikely to pop out of the openings 21, 22. Therefore, when manufacturing the flame retardant agent holding plate 10, there is no need to manually repair the flame retardant agent holding plate 10 during manufacturing, and therefore it is easy to put the manufacturing process of the flame retardant agent holding plate 10 into an line. In this manner, the flame retardant agent holding plate 10 can be easily manufactured.

[0080] In addition, because the one-side opening 21 and the other-side opening 22 are non-through openings, there is no need to provide a sealing layer on the one surface S1 side or the other surface S2 side of the wooden base material 20 in order to prevent the flame-retardant-containing solid 30 from falling out of the one-side opening 21 or the other-side opening 22. Therefore, it is possible to prevent the thickness of the flame-retardant-holding plate 10 from becoming thicker than the thickness of the wooden base material 20. Furthermore, since the position of the center point 21a of the one-side opening 21 and the position of the center point 22a of the other-side opening 22 are offset in both the first direction X and the second direction Y, even if a portion of one surface S1 of the flame-retardant chemical holding plate 10 that is not the one-side opening 21 burns and the combustion progresses downward in the thickness direction Z, the other-side opening 22 filled with the flame-retardant chemical-containing solid 30 is located below that portion in the thickness direction Z, so that the combustion can be prevented from progressing downward in the thickness direction Z. In this way, the flame-retardant agent holding plate 10 can be both thin and fire-resistant. The flame retardant agent holding plate and fire-resistant wood composite material of the present invention can be used by being attached to, for example, a wall, a floor, or a ceiling.

[0081] 5(a) to (c) show examples of preferred embodiments of the fire-resistant wooden structural material of the present invention. The fire-resistant wooden structural material of the present invention is a structural square timber used as a beam or pillar of a wooden building. The fire-resistant wooden structural material 7A shown in Figs. 5(a) and (b) is a structural square timber used as a pillar of a wooden building, and includes a load-bearing portion 8 and a fire-resistant coating layer 9. 5(a) shows a fire-resistant wooden structural member 7A having a load-bearing portion 8 and a fire-resistant coating layer 9. The fire-resistant wooden structural member 7A is a structural square timber used as a pillar in a wooden building. The load-bearing portion 8 is a square timber, and its cross-sectional design is such that it is structurally safe to withstand long-term loads (long-term loads) such as fixed loads and live loads. Such cross-sectional designs are well known. The cross-sectional shape of the load-bearing portion 8 is rectangular, and the vertical and horizontal lengths of the load-bearing portion 8 in the cross-section of the fireproof wooden structural material 7A can be changed as appropriate depending on the shape or size of the beams or columns.

[0082] The fire-resistant coating layer 9 is arranged so as to cover four side surfaces along the axial direction of the load-supporting portion 8. Each of the fire-resistant coating layers 9 covering each side surface includes a flame-retardant agent holding plate 10. More specifically, each of the fire-resistant coating layers 9 has a flame-retardant agent holding plate laminated portion 40 in which a plurality of flame-retardant agent holding plates 10 are laminated in the thickness direction. The flame-retardant agent holding plate laminated portion 40 has a configuration similar to that of the above-mentioned fire-resistant wood composite material 1, and has a first direction and a second direction perpendicular to the first direction in a plan view. The fire-resistant coating layer 9 has a decorative layer 5 in addition to the flame-retardant agent holding plate laminated portion 40. As the decorative layer 5, the same one as the decorative layer 5 of the above-mentioned fire-resistant wood composite material 1 can be used. Note that the fire-resistant coating layer 9 does not necessarily have to have the decorative layer 5, and may not have the decorative layer 5. Also, each of the fire-resistant coating layers 9 may have only one flame-retardant agent holding plate 10 instead of having the flame-retardant agent holding plate laminated portion 40. Furthermore, a fire-resistant coating layer 9 having a flame-retardant agent holding plate laminate portion 40 and a fire-resistant coating layer 9 having only one flame-retardant agent holding plate 10 may coexist.

[0083] In Fig. 5(a), the portion 9e of the fire-resistant coating layer 9 extending from the portion where the load-supporting portion 8 exists is formed by a fire-resistant coating layer 9 having an L-shaped cross section, which is formed by joining the fire-resistant coating layers 9 located on both sides of a corner of the load-supporting portion 8. Alternatively, the portion 9e of the fire-resistant coating layer 9 extending from the portion where the load-supporting portion 8 exists may be formed by extending the fire-resistant coating layer 9 along one side of the load-supporting portion 8 beyond the portion 9s where the load-supporting portion 8 exists, as shown in Fig. 5(b).

[0084] The fire-resistant coating layer 9 of the fire-resistant wooden structural material 7A includes the flame retardant agent holding plate 10 in which the wood base material 20 is cut off by the flame retardant agent-containing solid matter 30 filled in the openings 21 and 22, so that, for example, when the fire-resistant coating layer 9 of the fire-resistant wooden structural material 7A burns, the fire-resistant coating layer 9 is less likely to have large cracks, and the combustion is less likely to propagate to the load-supporting portion 8. Also, the fire-resistant coating layer 9 of the fire-resistant wooden structural material 7A includes the flame retardant agent holding plate 10 in which the positions of the center points 21a of the openings 21 on one side and the center points 22a of the openings 22 on the other side are offset in both the first direction X and the second direction Y. Therefore, for example, when the fire-resistant coating layer 9 burns, the combustion can be prevented from progressing downward in the thickness direction Z, and the combustion is less likely to propagate to the load-supporting portion 8.

[0085] Next, a fireproof wooden structural material 7B, which is another embodiment of the fireproof wooden structural material of the present invention, will be described with reference to Fig. 5(c). Regarding the fireproof wooden structural material 7B shown in Fig. 5(c), differences from the fireproof wooden structural material 7A shown in Fig. 5(a) and (b) will be described. Points that are not specifically described are the same as those of the fireproof wooden structural material 7A, and the description of the fireproof wooden structural material 7A applies as appropriate.

[0086] The fireproof wooden structural member 7B shown in Fig. 5(c) is a structural square timber used as a beam in a wooden building. In the fireproof wooden structural member 7B, the fireproof coating layer 9 is arranged so as to cover three side surfaces along the axial direction of the load-bearing portion 8. The load-bearing portion 8 of the fireproof wooden structural member 7B exists from the center of the cross section to the side surface on which the fireproof coating layer 9 is not formed. The side surface of the fireproof wooden structural member 7B on which the fireproof coating layer 9 is not formed may be covered from above by placing a floor or the like thereon. Although the preferred embodiment of the fire-resistant wood composite material of the present invention has been described above, the present invention is not limited to such an embodiment and can be modified as appropriate. For example, in the fire-resistant wood composite material 1 of this embodiment, the positions of the center points 21a, 22a of the one-side opening 21 and the other-side opening 22 are offset in both the first direction X and the second direction Y, but the positions of the center points 21a, 22a of the one-side opening 21 and the other-side opening 22 may be offset in either the first direction X or the second direction Y. Even in this case, the same effect as that of the fire-resistant wood composite material 1 of this embodiment is achieved.

[0087] Moreover, the positions of the center points 21a of the one-side holes 21 in the second direction Y of the first one-side holes 21 constituting the first one-side hole row 21R adjacent to each other in the first direction X do not necessarily have to coincide with each other, and the positions of the center points 21a of the one-side holes 21 in the second direction Y may be different. For example, the first one-side hole rows 21R adjacent to each other in the first direction X may be shifted by a half pitch or by two-thirds of a pitch in the second direction Y. Moreover, the positions of the center points 21a of the one-side holes 21 in the first direction X of the first one-side holes 21 constituting the second one-side hole row 21L adjacent to each other in the second direction Y may be different. For example, the second one-side hole rows 21L adjacent to each other in the second direction Y may be shifted by a half pitch or by two-thirds of a pitch in the first direction X.

[0088] The other-side openings 22 constituting the first other-side opening row 22R adjacent in the first direction X do not necessarily have to have the same position of the center points 22a of the other-side openings 22 in the second direction Y, and the positions of the center points 22a of the other-side openings 22 in the second direction Y may be different. For example, the first other-side opening rows 22R adjacent in the first direction X may be shifted by a half pitch or by two-thirds of a pitch in the second direction Y. The other-side openings 22 constituting the second other-side opening row 22L adjacent in the second direction Y may have different positions of the center points 22a of the other-side openings 22 in the first direction X, and for example, the second other-side opening rows 22L adjacent in the second direction Y may be shifted by a half pitch or by two-thirds of a pitch in the first direction X.

[0089] In this embodiment, the fire-resistant wood composite material 1 is a rectangular panel, the first direction X is a direction parallel to one side of the panel, and the second direction Y is a direction parallel to a side perpendicular to the one side. However, the first direction X may be defined to have an angle greater than 0 degrees and less than 90 degrees with respect to the side of the panel, and the second direction Y may be defined as the direction perpendicular to the first direction X. EXAMPLES

[0090] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited to these examples.

[0091] Example 1 A flame retardant holding plate having the same structure as the flame retardant holding plate 10 shown in FIG. 2 was manufactured. Specifically, a plywood having a vertical length of 400 mm, a horizontal length of 350 mm, and a thickness of 24 mm was used as the wood substrate. The one-side opening had a diameter of 10 mm, a depth of 14 mm, and the interval between the one-side openings in the first and second directions was 20 mm. The other-side opening had a diameter of 10 mm, a depth of 14 mm, and the interval between the other-side openings in the first and second directions was 20 mm. The one-side opening was filled with a curable composition having the following composition in a volume ratio of 100% to the opening, and then heated to 60° C. and cured for 6 hours to form a flame retardant-containing solid material as a cured product. The flame retardant-containing solid material of the other-side opening was also formed in the same manner as the flame retardant-containing solid material of the one-side opening. Two flame retardant holding plates manufactured in this way were laminated in the thickness direction. The two flame retardant holding plates were laminated so that the openings formed on the opposing surfaces did not overlap. A softwood plywood having a vertical length of 400 mm, a horizontal length of 350 mm, and a thickness of 48 mm was arranged on one surface in the thickness direction of the laminated flame retardant holding plates. A resorcinol-based adhesive was used to bond the flame retardant holding plate and the plywood. The surfaces of the laminate of the flame retardant holding plate and the plywood produced in this way other than the surface on the flame retardant holding plate side were cured with a ceramic blanket and a gypsum board to prepare a test specimen of Example 1.

[0092] <Composition of the curable composition> Solid flame retardant: Boric acid, 70% by weight Curing compound: 3-glycidoxypropyltrimethoxysilane, 23% by weight Curing catalyst: Aluminum-based curing catalyst (ACS, Hope Pharmaceutical Co., Ltd.), 7% by mass

[0093] Example 2 A test specimen for Example 2 was produced in the same manner as in Example 1, except that the depth of the one-surface opening and the other-surface opening in Example 1 was changed to 20 mm.

[0094] (Combustion test 1) The test specimens obtained in Examples 1 and 2 were placed in a combustion test furnace. The test specimens were arranged so that the longitudinal direction of the surface on the side of the flame retardant agent holding plate coincided with the vertical direction. In the test specimen, the surface on the side of the flame retardant agent holding plate was the heating surface that was heated on one side. Then, the test specimens were heated for one hour by the ISO834-1 standard heating assuming a normal fire, and after the heating, the test specimens were left to cool in the furnace for four hours. In this case, in Examples 1 and 2, the temperature change was measured at the positions where the depth from the heating surface was 12 mm, 24 mm, 36 mm, and 48 mm at the upper boundary of the two boundary lines when the heating surface was divided into three equal parts in the vertical direction (referred to as Top 12, Top 24, Top 36, and Top 48 in Figs. 6 and 7), and at the positions where the depth from the heating surface was 12 mm, 24 mm, 36 mm, and 48 mm at the lower boundary of the two boundary lines (referred to as Bottom 12, Bottom 24, Bottom 36, and Bottom 48 in Figs. 6 and 7), and the temperature change over time at each position was confirmed. The temperature change over time at each position in Example 1 is shown in Fig. 6, and the temperature change over time at each position in Example 2 is shown in Fig. 7.

[0095] In Examples 1 and 2, the burning was confirmed, and it was confirmed that the board had one-hour fire resistance. Specifically, in both Examples 1 and 2, the temperatures at the positions 36 mm and 48 mm deep from the heated surface did not reach 250°C, which is the ignition temperature of wood. In other words, of the two stacked flame retardant agent holding plates, the flame retardant agent holding plate on the opposite side to the heated surface was not burning. In addition, at the positions 12 mm and 24 mm deep from the heated surface, the temperature gradually decreased after the end of heating (one hour after the start of heating), and no re-rise in temperature was observed, so it can be seen that the burning did not continue and the burning had stopped. The carbonization depth was 29 mm in Example 1 and 26 mm in Example 2. This shows that by increasing the depth of the one-side openings or the other-side openings and increasing the height of the flame retardant-containing solid material, the fire resistance of the fire-resistant wood composite material can be improved without increasing the number of layers of the flame retardant-holding plate.

[0096] Example 3 A laminate consisting of two flame retardant agent holding plates manufactured in the same manner as in Example 1 was adhered to the four sides along the height direction of a cedar pillar measuring 120 mm in length, 120 mm in width, and 1000 mm in height to prepare a test specimen for Example 3. As in Example 1, the two flame retardant agent holding plates were stacked such that the openings formed on the opposing surfaces did not overlap.

[0097] Example 4 A test specimen for Example 4 was produced in the same manner as in Example 3, except that the two flame retardant chemical holding plates were laminated so that the openings formed on the opposing surfaces of each plate completely overlapped each other (see FIG. 4).

[0098] (Combustion test 2) The test specimens obtained in Examples 3 and 4 were placed in a test furnace in an upright position so that the height direction was aligned with the vertical direction, and each of the four sides was heated for one hour using the ISO834-1 standard heating method, which assumes a normal fire. After heating, the specimens were allowed to cool in the furnace for four hours. At that time, the temperature changes were measured at the center of the height direction of the test specimens, at the four corners of the cross section of the cedar column, and at the center of each of the four sides of the cross section. The positions where the temperature changes were measured are shown by black and white dots in Figures 8 and 9. In Figures 8 and 9, the black dots indicate the four corners of the cross section of the cedar column, and the white dots indicate the center of each of the four sides of the cross section. The results of measuring the temperature changes at each position are shown in Figures 10 and 11, respectively.

[0099] In Examples 3 and 4, the extinction of fire was confirmed, and it was confirmed that the material had one-hour fire resistance. Specifically, in Examples 3 and 4, the temperatures at all positions where the temperature change was measured did not reach 250°C, which is the ignition temperature of wood. In other words, the combustion did not reach the cedar pillar. Since the extinction of fire was confirmed in both Examples 3 and 4, it can be seen that in the fire-resistant wood composite material of the present invention, the positional relationship between the laminated flame retardant agent holding plates can be arbitrarily set. In addition, when comparing Examples 3 and 4, it can be seen that Example 3 has less temperature variation and a lower maximum temperature, and therefore Example 3 has better fire resistance than Example 4. In Example 3, the two flame retardant chemical holding plates are laminated so that the openings formed on the opposing surfaces do not overlap, and in Example 4, the two flame retardant chemical holding plates are laminated so that the openings formed on the opposing surfaces completely overlap. When the two flame retardant chemical holding plates are laminated so that the openings formed on the opposing surfaces partially overlap, it is expected that the fire resistance performance will be between that of Examples 3 and 4. [Explanation of symbols]

[0100] 1 Fire-resistant wood composite 10. Flame retardant holding plate S1 One side of the flame retardant holding plate S2 Other side of flame retardant holding plate 20 Wood base material 21 Opening on one side 22 Opening on the other side 25 Hole overlap area 30 Solids containing flame retardants 5. Decorative layer 7 Fireproof wooden structural materials 8 Load support part 9 Fireproof coating layer 40 Flame retardant agent retaining plate laminate X 1st direction Y Second direction Z thickness direction

Claims

1. A flame retardant agent holding plate used for forming a fire-resistant coating layer, A first direction and a second direction perpendicular to the first direction, The present invention comprises a wood base material having non-through holes on each of one side and the other side, and a solid material containing a flame retardant agent filled in each of the holes, the opening on one surface side and the opening on the other surface side have center points offset from each other in a first direction, a second direction, or both directions; The opening on one surface side and the opening on the other surface side do not overlap in a plan view of the flame retardant agent holding plate, the flame retardant chemical holding plate has an aperture overlap region in a central region in a thickness direction thereof, in which both a part of the aperture on one surface side and a part of the aperture on the other surface side are present; The flame retardant-containing solid material is either or both of a cured product of a curable composition containing a solid flame retardant and a compact containing a solid flame retardant; The cured product of the curable composition is a product that is filled into the openings in a paste state and then cured, or a product that is filled into the openings in a solid state, A flame retardant agent holding plate that has not been impregnated with a liquid treatment agent.

2. A flame retardant agent retaining plate as described in claim 1, wherein the cured product of the curable composition is filled into the opening in a solid state.

3. A flame retardant agent retaining plate as described in claim 1 or 2, wherein the flame retardant agent-containing solid is a cured product of a curable composition containing a solid flame retardant, and the curable composition contains the solid flame retardant, a curable compound and a curing catalyst.

4. A flame retardant agent retaining plate described in any one of claims 1 to 3, wherein an adhesive is applied to the surface of the flame retardant agent-containing solid or to the peripheral surface of the opening in which the flame retardant agent-containing solid is contained.

5. The flame retardant agent holding board according to any one of claims 1 to 4, wherein the wood base material is a plywood made of a laminate of a plurality of veneers.

6. A fire-resistant wood composite material having a structure in which a plurality of flame retardant agent holding plates are laminated, A fire-resistant wood composite material, wherein the flame retardant agent-holding plate is the flame retardant agent-holding plate according to any one of claims 1 to 5.

7. A fire-resistant wooden structural member comprising a load-bearing portion made of a square timber and a fire-resistant coating layer covering three or four axial sides of the load-bearing portion, A fire-resistant wooden structural material, wherein each of the fire-resistant coating layers covering each of the side surfaces includes the flame retardant agent holding plate according to any one of claims 1 to 5.

8. The fire-resistant wooden structural material according to claim 7, wherein each of the fire-resistant coating layers has a flame-retardant agent holding plate laminated portion in which a plurality of flame-retardant agent holding plates according to any one of claims 1 to 5 are laminated in the thickness direction.

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