Fire-resistant wooden building materials

Abstract

To provide a fireproof wooden building member which delays combustion when fire occurs, and is widely usable in a building.SOLUTION: A fireproof wooden building member includes a wooden base material, and a coating layer formed in at least a part of a surface, a rear face and side faces of the wooden base material, wherein the coating layer has a plurality of hollow ceramics and a resin binder connecting the plurality of hollow ceramics, the coating layer converts heat applied to at least one of the wooden base material and the coating layer into far-infrared rays and radiates the far-infrared rays, and the plurality of hollow ceramics contain a plurality of hollow ceramics having different particle diameters.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a wooden building member, specifically a fire-resistant wooden building member having fire resistance.

Background Art

[0002] In various places, there are many buildings of various types such as houses, stores, commercial facilities, public facilities, and medical facilities. The materials used for these buildings are selected according to their characteristics, size, use, required specifications, etc. In particular, for structures such as columns, beams, outer walls, inner walls, roofs, and floors of buildings, concrete, new building materials, wood, or combinations thereof are used. Of course, concrete, new building materials, wooden members, or combinations thereof are also used for the foundation and framework parts of buildings.

[0003] In addition, materials other than concrete, new building materials, and wooden members may also be used.

[0004] Recently, not only concrete but also new building materials and wooden members are increasingly used for structures such as columns, beams, outer walls, inner walls, roofs, and floors. For example, the use of wooden members for outer walls and floors has been increasing. This is because buildings constructed with wooden members can reduce the environmental load in houses, stores, public facilities, etc.

[0005] Moreover, occupants and users can also feel relaxed physically and mentally in buildings made of wooden members. Of course, there are also advantages in enhancing the habitability. Buildings made of wooden members have advantages such as high adaptability to the outside air temperature (cool in summer and warm in winter indoors) or high adaptability to indoor humidity. Therefore, the convenience for occupants and users is also enhanced.

[0006] In addition, buildings made of wooden members bring a refreshing effect to the mental state of occupants and users. Especially in our country, since wooden buildings have been central in the past, there are high advantages for the spirituality of the Japanese people.

[0007] Here, compared with concrete and new building materials, wooden members can be lightweight. If the building members, which are the materials of a building, can be lightweight, it is possible to reduce the costs of foundation work and construction work. In addition, there is also the merit of being able to shorten the construction period.

[0008] Moreover, there is the fact that most of Japan's land is forest. Naturally, there are many trees in many forests, and there is a very large amount of wood raw materials. However, logging trees from Japanese forests to make wood does not progress from a cost perspective, and there is an aspect that domestic forest resources are not being effectively utilized. In reality, most of the wood used in processed products such as domestic buildings and furniture is imported.

[0009] If the utilization of Japan's forest resources does not progress in this way, there are problems such as the treatment of thinned wood and the replanting of forests not progressing. As a result, the cycle of forest management is not generated, and there is a problem leading to forest degradation.

[0010] In order to utilize the abundant forest resources in Japan, it is necessary for wooden members to be used in a variety of buildings. For example, wooden members may be used in structural parts such as columns, beams, exterior walls, interior walls, roofs, and floor surfaces of buildings. By this use, buildings such as houses, stores, facilities, and apartment houses are constructed. If the construction of houses, stores, facilities, apartment houses, etc. using such wooden members spreads, the utilization of Japan's forest resources will progress. In this way, Japan's forest management will be promoted.

[0011] Thus, it is desired that wooden building members be used in many buildings.

[0012] However, wooden building members are considered to burn during a fire and have weak fire response and durability. When a fire occurs, there are concerns such as being likely to lead to burning and being likely to spread to the surroundings. Due to such concerns, there is a current situation where the use of wooden building members in buildings has not spread.

[0013] Therefore, technologies for imparting fire resistance to wooden members have been proposed (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3).

Prior Art Documents

Patent Documents

[0014]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0015] Patent Document 1 discloses a wooden fire-resistant member 1 including a load-supporting portion 2, a fire-resistant coating layer 3 covering the periphery of the load-supporting portion 2, and a finished wood layer 4 provided around the outside of the fire-resistant coating layer 3, wherein the fire-resistant coating layer 3 is made of a wet fire-resistant coating material, and a moisture barrier layer 5 is formed between the load-supporting portion 2 and the fire-resistant coating layer 3, and between the fire-resistant coating layer 3 and the finished wood layer 4.

[0016] Patent Document 1 aims to prevent the disadvantages caused by moisture impregnation in fire-resistant wood by providing a moisture barrier layer such as a moisture barrier sheet.

[0017] However, the fire-resistant coating layer in Patent Document 1 is realized by spraying materials such as rock wool and white cement. Such a coating layer made of such materials has a problem that it requires a thickness to enhance the fire resistance, resulting in an increase in weight. That is, the weight of the wooden fire-resistant member increases. When building members such as wooden fire-resistant members become heavy, not only does the scale of the foundation work increase, but also the processes and labor of the construction work itself increase, leading to an increase in construction costs. There is also a concern about a decrease in safety during construction work.

[0018] Also, similar to gypsum boards, the coating layer applied by spraying materials such as rock wool can gain time until the coating layer burns during a fire. However, once the coating layer starts burning, the wood will burn all at once. This is because when heat from a fire is applied, the mechanism of heat rise comes into play.

[0019] Patent Document 2 discloses a fire-resistant wood in which the fire-resistant wood 10 includes a prismatic core material 12 made of a wood material, a heat buffer material 14A attached to the corners of the core material 12, a fire-resistant material 18A attached to the outer surface side of the core material 12, and a finishing material 20 supported by the heat buffer material 14A and covering the fire-resistant material 18A and the heat buffer material 14A.

[0020] The technology of Patent Document 2 forms a complex structure for fire resistance. However, it is necessary to form a complex structure, which increases the labor and cost of processing and is not suitable for many buildings. The construction cost also increases, and it is difficult to handle, making construction work difficult.

[0021] In addition, due to its complex shape, there is also a problem that it is not suitable for wall materials, floor materials, etc. in a building. Also, fire resistance is achieved by providing a heat buffer material inside. However, the temperature of the entire fire-resistant wood still rises due to the heat of the fire, and the fire-resistant wood will burn due to the temperature rise.

[0022] Patent Documents 1 and 2 also only focus on weakening combustion in a fire by incorporating some materials that are difficult to burn, different from wood. In reality, if the temperature rise cannot be suppressed, the fire-resistant wood will still burn during a fire.

[0023] Patent Document 3 discloses a fire-resistant modified wood material in which a plurality of unit woods 14 are joined and impregnated with a non-combustible agent for performing non-combustion, semi-non-combustion, or flame-retardant treatment on a wood material. The unit wood 14 is arranged such that its end face k becomes the front and back sides in the thickness direction of the fire-resistant modified wood material 16, and a fire-resistant modified wood into which a non-combustible agent is injected and impregnated from the end face k is disclosed.

[0024] Patent Document 3 has problems that the cost as a building material becomes extremely high in order to cope with fire during wood processing. In addition, it is difficult to ensure the distribution volume, and there is also a problem that it is difficult to use in many buildings. In addition, since the utilization is biased towards specific parts of the wood, it is difficult to effectively utilize forest resources. Also, since it is based on impregnation, there is a problem that the weight increases and the construction cost becomes high.

[0025] Moreover, since it is a building material injected with a chemical agent, there is also a concern that the residents and others will be affected by gasification after the building is completed. There is also a concern that some affected gas will be generated during a fire.

[0026] The prior art has problems such as (1) the weight increases, increasing the building material cost and the construction cost, (2) causing construction labor, (3) being difficult to achieve delaying combustion during a fire, and (4) poor usability due to the complexity of the structure of the building material.

[0027] In view of these problems, an object of the present invention is to provide a fire-resistant wooden building member that delays combustion during a fire and can be widely used in buildings.

Means for Solving the Problems

[0028] The fire-resistant wooden building member of the present invention A fire-resistant wooden building member having fire resistance, comprises a wooden base material, and a coating layer formed on at least a part of the front surface, back surface, and side surfaces of the wooden base material, The coating layer comprises a plurality of hollow ceramics, a resin binder connecting the plurality of hollow ceramics to each other, and has The coating layer converts heat applied to at least one of the wooden base material and the coating layer into far-infrared rays and radiates it, The plurality of hollow ceramics include hollow ceramics of a plurality of different particle sizes see, the wooden base material is a wall material, the particle sizes of the plurality of hollow ceramics are from 10 μm to 150 μm, the average particle size of the plurality of hollow ceramics is 40 μm, the particle sizes of the plurality of hollow ceramics include those with a particle size of 10 μm and those with a particle size of 150 μm, and the hollow ceramics with a particle size of 10 μm enter the gaps formed between the hollow ceramics with a particle size of 150 μm, the hollow ceramics have an outer surface and an internal space, at least one of the conversion of far-infrared rays on the outer surface and the conversion of far-infrared rays by diffuse reflection in the internal space, the heat applied to at least one of the wooden base material and the coating layer is converted into far-infrared rays, the plurality of hollow ceramics form a plurality of ceramic layers composed of hollow ceramics with different main particle sizes in the coating layer, each of the plurality of ceramic layers radiates far-infrared rays obtained by converting the applied heat, by the radiation of far-infrared rays by the coating layer, it is possible to suppress the temperature rise of the wooden base material due to the heat applied to the fire-resistant wooden building member, the thickness of the coating layer is defined as follows in terms of the weight of the coating material forming the coating layer per unit area of the wooden base material, Weight of the coating material: 150 g to 280 g / m 2 (per unit area of the wooden base material) is defined by, the thickness of the coating layer formed after drying the coating material is 154 μm or more and 291 μm or less 。

Advantages of the Invention

[0029] The fire-resistant wooden building member of the present invention only has a very thin coating layer applied to the surface of the wooden base material, and it is possible to suppress an increase in weight compared to the original wooden base material. As a result, the building material cost, construction cost, and labor in construction can be reduced. In addition, the safety during construction can also be enhanced.

[0030] Further, the coating layer does not exhibit fire resistance physically or chemically, but converts heat due to a fire or the like into far-infrared rays and radiates them. Thereby, it is possible to suppress an increase in the temperature of the building member due to heat such as a fire. By suppressing this increase in temperature, the combustion during a fire can be delayed, and the fire resistance that a wooden building should have can be enhanced.

[0031] Further, since only a coating layer is applied to the surface of the wooden base material, there is no complexity in the fire-resistant wooden building member, the manufacturing cost of the fire-resistant wooden building member can be reduced, and in addition, the utilization rate of the raw material wood can also be increased. As a result, the effective utilization of forest resources can be enhanced.

Brief Description of the Drawings

[0032]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0033] The fire-resistant wooden building member according to the first invention of the present invention includes a wooden base material and a coating layer formed on at least a part of the front surface, back surface, and side surface of the wooden base material. The coating layer includes a plurality of hollow ceramics and a resin binder that connects the plurality of hollow ceramics to each other. has The coating layer converts heat applied to at least one of the wooden base material and the coating layer into far-infrared rays and radiates it. The plurality of hollow ceramics include hollow ceramics having a plurality of different particle sizes.

[0034] With this configuration, while using wood as the base material, the fire resistance can be enhanced, making it applicable to various buildings. In addition, unlike building materials that laminate special fire-resistant members, the increase in weight can also be suppressed. As a result, ease of handling, ease of construction, and reduction of construction costs can also be achieved.

[0035] In the fire-resistant wooden building member according to the second invention of the present invention, in addition to the first invention, the particle size of the plurality of hollow ceramics is 10 μm to 150 μm.

[0036] With this configuration, due to the variation in particle size, heat containing various components can be efficiently and surely converted into far-infrared rays. Thereby, the fire resistance can be enhanced.

[0037] In the fire-resistant wooden building member according to the third invention of the present invention, in addition to the second invention, the average particle size of the plurality of hollow ceramics is 40 μm.

[0038] With this configuration, the formation of the coating layer can be surely performed.

[0039] In the fire-resistant wooden building member according to the fourth invention of the present invention, in addition to any one of the first to third inventions, the hollow ceramics contain a metal oxide.

[0040] With this configuration, the conversion into far-infrared rays can be efficiently performed.

[0041] In the fire-resistant wooden building member according to the fifth invention of the present invention, in addition to the fourth invention, the metal oxide contains at least one of aluminum oxide (Al2O3), magnesium oxide (MgO), ferric oxide (Fe2O3), sodium oxide (Na2O), potassium oxide (K2O), titanium dioxide (TiO2), cerium oxide (CeO2), silicon dioxide (SiO2), and antimony trioxide (Sb2O3).

[0042] With this configuration, the conversion into far-infrared rays can be efficiently performed.

[0043] In the fire-resistant wooden building member according to the sixth invention of the present invention, in addition to the fifth invention, the coating layer contains the hollow ceramics made of two or more kinds of the metal oxides.

[0044] With this configuration, conversion into far-infrared rays can be surely realized in response to combustion components and the like and combustion characteristics. It is possible to cope with various types of fires.

[0045] In the fire-resistant wooden building member according to the seventh invention of the present invention, in addition to any one of the first to sixth inventions, the resin binder is an acrylic resin.

[0046] With this configuration, the adhesion between the hollow ceramics forming the coating layer can be surely performed.

[0047] In the fire-resistant wooden building member according to the eighth invention of the present invention, in addition to any one of the first to seventh inventions, the hollow ceramics has an outer surface and an internal space, At least one of the conversion of the outer surface into far-infrared rays and the conversion of far-infrared rays by diffuse reflection in the internal space, the heat applied to at least one of the wooden base material and the coating layer is converted into far-infrared rays.

[0048] With this configuration, the fire resistance can be improved.

[0049] In the fire-resistant wooden building member according to the ninth invention of the present invention, in addition to any one of the first to eighth inventions, the plurality of hollow ceramics form a plurality of ceramic layers in the coating layer, Each of the plurality of ceramic layers radiates far-infrared rays obtained by converting the applied heat.

[0050] With this configuration, it is possible to convert into far-infrared rays corresponding to each of the combustion components.

[0051] In the fire-resistant wooden building member according to the tenth invention of the present invention, in addition to any one of the first to eighth inventions, the plurality of ceramic layers are formed by a difference in the particle size of the hollow ceramics or a method of forming the coating layer.

[0052] With this configuration, it can be converted into far-infrared rays corresponding to each of the combustion components.

[0053] In the fire-resistant wooden building member according to the 11th invention of the present invention, in addition to any one of the 1st to 10th inventions, due to the radiation of far-infrared rays by the coating layer, it is possible to suppress the temperature rise in the wooden base material due to the heat applied to the fire-resistant wooden building member.

[0054] With this configuration, the fire resistance can be improved. The fire-resistant wooden building member according to the 12th invention of the present invention, in addition to any one of the 1st to 11th inventions, the thickness of the coating layer is defined as follows in terms of the weight of the coating material forming the coating layer per unit area of the wooden base material: Weight of coating material: 150 g to 280 g / m 2 (Per unit area of wooden base material) It is defined by. With this configuration, it is possible to realize reliable conversion and radiation into far-infrared rays without excessive enhancement of heat insulation inside the building.

[0055] In the fire-resistant wooden building member according to the 13th invention of the present invention, in addition to any one of the 1st to 11th inventions, the thickness of the coating layer is 154 μm or more and 291 μm or less.

[0056] With this configuration, it is possible to realize sufficient fire resistance while suppressing weight increase with a minimum thickness.

[0057] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0058] (Embodiment 1)

[0059] (Overall outline) The overall outline of the fire-resistant wooden building member in Embodiment 1 will be described.

[0060] FIG. 1 is a perspective view of a fire-resistant wooden building member according to Embodiment 1 of the present invention. FIG. 2 is a side view of the fire-resistant wooden building member according to Embodiment 1 of the present invention. FIG. 3 is an explanatory view for explaining the configuration of a coating layer of the fire-resistant wooden building member according to Embodiment 1 of the present invention.

[0061] The fire-resistant wooden building member 1 is used for structural parts such as columns, beams, outer walls, inner walls, roofs, and floor surfaces of wooden buildings. Alternatively, it is also used for structural parts such as columns, beams, outer walls, inner walls, roofs, and floor surfaces of buildings that partly consist of wood (buildings in which wooden parts are mixed with concrete or other materials). At this time, the fire-resistant wooden building member 1 may be used for all or part of these structural parts such as columns, beams, outer walls, inner walls, roofs, and floor surfaces.

[0062] For example, in order to delay the burning of a building in the event of a fire, the fire-resistant wooden building member 1 may be used for the outer wall and the inner wall, and ordinary wooden building materials may be used for other parts.

[0063] The purpose of the fire-resistant wooden building member 1 is not to prevent it from burning completely when a fire breaks out in a wooden building, but to delay the burning time. In building standards and the like, it is also important to delay the burning rather than prevent it from burning completely when a fire breaks out in a wooden building (and its surroundings). For example, increasing the time required for the outer wall to burn down is one of the safety standards for wooden buildings.

[0064] Therefore, the fire-resistant wooden building member 1 can delay burning in the event of a fire or the like.

[0065] The wooden building member 1 includes a wooden base material 2 and a coating layer 3. The coating layer 3 is formed on at least a part of the front surface, back surface, and side surfaces of the wooden base material 2. In FIGS. 1 and 2, the coating layer 3 is formed on the front surface or the back surface of the wooden base material 2. This is an example of the formation of the coating layer 3.

[0066] For the wooden base material 2, various woods such as cedar and cypress may be used. The shape, size, thickness, etc. may be selected according to whether it is used for any of the structural parts such as columns, beams, outer walls, inner walls, roofs, and floor surfaces. In FIGS. 1 and 2, a wide wooden base material 2 is shown by taking wall materials such as outer walls and inner walls as an example.

[0067] The coating layer 3 has a plurality of hollow ceramics 31 and a resin binder 32 that connects the plurality of hollow ceramics to each other. In FIG. 3, it is shown in a state where this configuration can be understood.

[0068] As shown in FIG. 3, the coating layer 3 includes a plurality of hollow ceramics 31. The plurality of hollow ceramics 31 are connected by a resin binder 32. By this connection, a substance containing the plurality of hollow ceramics 31 can form the coating layer 3. In addition, it is formed by adhering to the wooden base material 2.

[0069] Also, the plurality of hollow ceramics 21 include hollow ceramics 31 having a plurality of different particle sizes. As shown in FIG. 3, hollow ceramics 31 having different particle sizes are included in the coating layer 3.

[0070] The coating layer 3 converts the heat applied to at least one of the wooden base material 2 and the coating layer 3 into far-infrared rays and radiates them. In FIG. 3, an arrow Y2 indicating that heat is applied to the wooden base material 2 is shown. For example, the heat of a flame in a fire or the like is applied. The coating layer 3 converts the heat applied in the direction of this arrow Y2 into far-infrared rays and radiates them like arrow X.

[0071] Alternatively, in FIG. 3, heat may be applied to the coating layer 3 in the direction of arrow Y1. Similarly, it is heat from a flame or the like due to a fire. Regarding the heat applied by such an arrow Y1, the coating layer 3 also converts it into far-infrared rays. Furthermore, the converted far-infrared rays are radiated like arrow X1.

[0072] Thus, even when heat from a flame such as a fire is applied to the fire-resistant wooden building member 1, the coating layer 3 converts this heat into far-infrared rays and radiates it externally. By continuously converting the applied heat into far-infrared rays and radiating it, it is possible to suppress the heat from staying and accumulating in the fire-resistant wooden building member 1 (wooden base material 2). This suppression slows down the burning rate due to the applied heat in the fire-resistant wooden building member 1 (wooden base material 3). By delaying the burning rate, the burning time of the fire-resistant wooden building member 1 can be extended.

[0073] Thereby, the fire resistance during a fire in a wooden building can be enhanced. As described above, fire resistance does not mean not burning at all, but rather delaying burning. This is because the coating layer 3 continuously converts heat into far-infrared rays and radiates it, suppressing the applied heat from staying or accumulating.

[0074] In particular, when heat is applied, the coating layer 3 continuously converts this heat into far-infrared rays and radiates it. By the continuousness of this process, the burning of the fire-resistant wooden building member 1 due to the applied heat can be delayed. The more it is delayed, the longer the endurance time in a fire or the like becomes. By the increase in this endurance time, the durability of the wooden building using the fire-resistant wooden building member 1 of the present invention against fires and the like is enhanced. In particular, since the fire resistance standard can be satisfied, the spread of wooden buildings can be expected.

[0075] (Far-infrared ray conversion by hollow ceramics)

[0076] As described above, the coating layer 3 converts the heat applied to the fire-resistant wooden building member 1 into far-infrared rays and radiates it. The coating layer 3 includes a plurality of hollow ceramics 31. The hollow ceramics 31 has an internal space 310. The internal space 310 converts the applied heat into far-infrared rays by diffusely reflecting the heat inside.

[0077] FIG. 4 is a schematic diagram showing a state in which the hollow ceramics converts heat into far-infrared rays. As shown in FIG. 4, the heat applied in the internal space 310 diffusely reflects. Through this diffuse reflection, the heat is converted into far-infrared rays. The converted far-infrared rays are radiated.

[0078] In this way, by including a plurality of hollow ceramics 31, the coating layer 3 can convert heat into far-infrared rays.

[0079] Moreover, the plurality of hollow ceramics 31 included in the coating layer 3 include hollow ceramics 31 with different particle sizes. Due to the different particle sizes, more diffuse reflections occur in the respective internal spaces 310 of the hollow ceramics 31. In addition, diffuse reflections also occur between the hollow ceramics 31 with different particle sizes, and the conversion of heat into far-infrared rays occurs more effectively.

[0080] Furthermore, the heat applied contains components with different wavelengths. Each of these components with different wavelengths corresponds to hollow ceramics 31 with different particle sizes. Due to this correspondence, hollow ceramics 31 with a certain particle size convert the heat of a component with a certain wavelength into far-infrared rays. Hollow ceramics 31 with another particle size convert the heat of a component with another wavelength into far-infrared rays.

[0081] In this way, by including hollow ceramics 31 with different particle sizes, the applied heat can be efficiently and surely converted into far-infrared rays. When hollow ceramics 31 with different particle sizes are included, the entire heat having components with different wavelengths can be converted into far-infrared rays. Thereby, even when heat such as that from a fire is applied to the fire-resistant wooden building member 1, it is possible to more surely delay combustion.

[0082] Moreover, the hollow ceramics 31 also exhibit a mechanism of generating and radiating far-infrared rays by converting heat on their surfaces. When heat is applied, the surfaces of the hollow ceramics 31 convert this into far-infrared rays. Thereby, the coating layer 3 can successively convert the applied heat into far-infrared rays and radiate them. Thereby, even when heat such as that from a fire is applied to the fire-resistant wooden building member 1, combustion can be delayed.

[0083] From this point of view, it is preferable that the coating layer 3 contains hollow ceramics 31 with different particle sizes. By including hollow ceramics 31 with different particle sizes, the packing density of the hollow ceramics 31 in the coating layer 3 increases. This is because the hollow ceramics 31 with medium or small particle sizes enter the gaps formed between the hollow ceramics 31 with large particle sizes.

[0084] As a result, the number density of the hollow ceramics 31 contained in the coating layer 3 increases.

[0085] If the number density increases, the total surface area of the contained hollow ceramics 31 increases. As described above, the hollow ceramics 31 convert heat into far-infrared rays on their surfaces. With the increase in the total surface area of this entire surface, the amount of conversion into far-infrared rays increases. Due to this increase, the fire resistance ability to convert the applied heat into far-infrared rays is further enhanced. In this way, the coating layer 3 containing hollow ceramics 31 with different particle sizes contributes to the improvement of the ability to convert heat into far-infrared rays.

[0086] Here, it is also preferable that the particle sizes of the plurality of hollow ceramics 31 are in the range of 10 μm to 150 μm. It is also preferable that the average particle size is 40 μm.

[0087] With the particle sizes of the hollow ceramics 31 being in such a wide range, the applied heat can be surely and efficiently converted into far-infrared rays. Although the wavelengths included vary depending on the heat, the fact that the particle sizes of the hollow ceramics 31 vary within such a wide range enables conversion into far-infrared rays for any wavelength of heat or components.

[0088] Also, with the average particle size being 40 μm, the formation of the coating layer 3 becomes easy. The coating layer 3 may be formed by applying a paint containing the hollow ceramics 31 and the resin binder 32 to the surface of the wooden base material 2 or the like. In this case, with the average particle size of the hollow ceramics 31 being 40 μm, there is the merit that application and the like become easy. There is also the merit that a coating layer 3 with an appropriate thickness can be formed.

[0089] It is also preferable that the hollow ceramics 31 contain metal oxides. By containing such metal oxides, heat can be efficiently converted into far-infrared rays. Here, the metal oxides include at least one of aluminum oxide (Al2O3), magnesium oxide (MgO), ferric oxide (Fe2O3), sodium oxide (Na2O), potassium oxide (K2O), titanium dioxide (TiO2), cerium oxide (CeO2), silicon dioxide (SiO2), and antimony trioxide (Sb2O3).

[0090] By containing these metal oxides, the hollow ceramics 31 can efficiently and surely convert heat into far-infrared rays. The metal oxides promote diffuse reflection in the internal space 310 and generate far-infrared rays during the process of diffuse reflection. In this way, the coating layer 3 containing the hollow ceramics 31 containing metal oxides can efficiently and surely convert the heat applied to the fire-resistant wooden building member 1 into far-infrared rays.

[0091] In addition, since the hollow ceramics 31 contain metal oxides, the ability and efficiency of far-infrared ray conversion by the hollow ceramics 31 are increased. As described above, the hollow ceramics 31 convert heat into far-infrared rays and radiate it through diffuse reflection in its internal space and conversion on the surface.

[0092] When the hollow ceramics 31 contain metal oxides, the conversion effect into far-infrared rays can be enhanced. That is, the amount of far-infrared rays radiated by the hollow ceramics 31 can be increased. In addition to the hollow ceramics 31 being hollow and having a plurality of particle sizes, by containing metal oxides, heat can be efficiently converted and radiated into far-infrared rays.

[0093] The resin binder 32 connects the hollow ceramics 31 to each other. By connecting them, the coating layer 3 can be formed as one layer. Here, it is also preferable that the resin binder 32 is an acrylic resin. By being an acrylic resin, the hollow ceramics 31 can be more surely connected by the resin binder 32.

[0094] In addition, since it is an acrylic resin, the weight of the coating layer 3 can be reduced.

[0095] The coating layer 3 formed in this way can convert the applied heat into far-infrared rays and radiate them. This function can suppress the applied heat from staying and accumulating in the fire-resistant wooden building member 1.

[0096] By the radiation of far-infrared conversion by such a coating layer 3, it is possible to suppress the temperature rise in the wooden base material 2 due to the heat applied to the fire-resistant wooden building member 1. Since it is possible to suppress it, combustion in a fire or the like can be suppressed, and the combustion can be delayed. By delaying this, the fire resistance performance required for wooden buildings can be achieved.

[0097] (Embodiment 2)

[0098] Next, Embodiment 2 will be described. In Embodiment 2, various variations will be described.

[0099] (Multiple ceramic layers)

[0100] A plurality of hollow ceramics 31 can form a plurality of ceramic layers in the coating layer 3 depending on the structure and particle size resulting from their connection. FIG. 5 is a schematic diagram of a coating layer in which a plurality of ceramic layers are formed by the connection structure of the hollow ceramics. In FIG. 5, the coating layer 3 has a configuration including a first ceramic layer 311 and a second ceramic layer 312.

[0101] Each of the plurality of ceramic layers radiates far-infrared rays obtained by converting the applied heat. As shown in FIG. 5, the first ceramic layer 311 radiates far-infrared rays, and together with this, the second ceramic layer 312 also radiates far-infrared rays. Each ceramic layer has a mode of radiating far-infrared rays.

[0102] When forming the coating layer 3, for example, a coating material that is a raw material for the coating layer 3 is applied to the surface of the wooden base material 2 or the like. At this time, by applying the coating material in multiple times, a plurality of ceramic layers as shown in FIG. 5 can be formed.

[0103] Since the coating layer 3 includes a plurality of ceramic layers, conversion and radiation of far-infrared rays are performed in each ceramic layer. Conversion and radiation of far-infrared rays in the first ceramic layer 311 and conversion and radiation of far-infrared rays in the second ceramic layer 312 are respectively performed. By performing this respectively, more efficient conversion into far-infrared rays is performed.

[0104] In particular, when conversion into far-infrared rays is performed in each of the ceramic layers, far-infrared ray conversion is performed at spatially different locations. Thereby, the entire large number of hollow ceramics 31 is utilized for far-infrared ray conversion.

[0105] Also, when far-infrared ray radiation is performed in each of the ceramic layers, multi-faceted and multiple far-infrared ray radiation is performed. Thereby, even when heat is applied to the fire-resistant wooden building member 1, more heat is radiated as far-infrared rays. As a result, combustion can be delayed.

[0106] Also, even when heat is applied to the fire-resistant wooden building member 1 and the coating layer 3 gradually burns off, the remaining ceramic layer can maintain its function. Thereby, the function of radiating the applied heat as far-infrared rays is maintained for a longer time, and the combustion of the fire-resistant wooden building member 1 can be delayed.

[0107] Also, the plurality of ceramic layers of the coating layer 3 may be formed depending on the particle size of the hollow ceramics 31. FIG. 6 is a schematic diagram of a coating layer including a plurality of ceramic layers formed depending on the particle size of the hollow ceramics.

[0108] For example, if a coating material containing hollow ceramics 31 of a certain particle size is applied, and then a coating material containing hollow ceramics 31 of another particle size is applied, and this is repeated by applying a coating material containing hollow ceramics 31 of yet another particle size, a plurality of ceramic layers with different particle sizes as shown in FIG. 6 can be formed.

[0109] In FIG. 6, as an example, a first ceramic layer 311, a second ceramic layer 312, and a third ceramic layer 313 are formed. Each ceramic layer is formed due to the difference in the particle size of the hollow ceramics 31.

[0110] Each of the first ceramic layer 311, the second ceramic layer 312, and the third ceramic layer 313 converts the heat applied to the refractory wooden building member 1 into far-infrared rays and emits them. This state is as shown in FIG. 6.

[0111] Each of the plurality of ceramic layers formed due to the different particle sizes of the hollow ceramics 31 can perform far-infrared conversion corresponding to each of the different wavelength components included in the applied heat. As a result, the first ceramic layer 311 converts the heat of a certain wavelength component (or temperature component) into far-infrared rays and emits them. The second ceramic layer 312 converts the heat of another wavelength component (or temperature component) into far-infrared rays and emits them. The third ceramic layer 313 converts the heat of yet another wavelength component (or temperature component) into far-infrared rays and emits them.

[0112] Also, as shown in FIG. 7, a plurality of ceramic layers may be formed in the coating layer 3. FIG. 7 is a schematic diagram of the coating layer in Embodiment 2 of the present invention. In the coating layer 3, hollow ceramics 31 of different particle sizes are included. Due to the difference in the particle size of the hollow ceramics 31 with the main particle size, a plurality of ceramic layers are formed as shown in FIG. 7.

[0113] In FIG. 7, each of the plurality of ceramic layers includes a hollow ceramic layer 31 with different particle sizes. However, the first ceramic layer 311 is a ceramic layer centered on a hollow ceramic 31 with a small particle size, the second ceramic layer 312 is a ceramic layer centered on a hollow ceramic 31 with a medium particle size, and the third ceramic layer 313 is a ceramic layer centered on a hollow ceramic 31 with a large particle size.

[0114] In this way, although the ceramic layers contain hollow ceramics 31 with different particle sizes, a plurality of ceramic layers are formed according to the main particle size. Each of these plurality of ceramic layers converts heat into far-infrared rays and emits them. By this radiation, the combustion of the fire-resistant wooden building member 1 can be delayed.

[0115] In this way, it can be converted into far-infrared rays and emitted corresponding to each of the various components contained in the applied heat. Thereby, the coating layer 3 can surely and evenly convert the heat applied to the fire-resistant wooden building member 1 into far-infrared rays and emit them. As a result, it becomes possible to further delay the combustion by heat.

[0116] Also, as described above, due to the presence of a plurality of ceramic layers, even if one of the ceramic layers burns, the remaining ceramic layers can maintain their functions. Thereby, combustion can be delayed for a longer time.

[0117] (Including hollow ceramics of different metal oxides)

[0118] The hollow ceramic 31 contains a metal oxide. Further, the metal oxide includes at least one of aluminum oxide (Al2O3), magnesium oxide (MgO), ferric oxide (Fe2O3), sodium oxide (Na2O), potassium oxide (K2O), titanium oxide (TiO2), cerium oxide (CeO2), silicon dioxide (SiO2), and antimony trioxide (Sb2O3).

[0119] Here, it is also preferable that the hollow ceramics 31 constituting the coating layer 3 contains at least two or more types of metal oxides such as aluminum oxide (Al2O3), magnesium oxide (MgO), ferric oxide (Fe2O3), sodium oxide (Na2O), potassium oxide (K2O), titanium oxide (TiO2), cerium oxide (CeO2), silicon dioxide (SiO2), and antimony trioxide (Sb2O3).

[0120] By including hollow ceramics 31 made of two or more different types of metal oxides in the coating layer 3, each hollow ceramics 31 can convert heat into far-infrared rays corresponding to different components (such as wavelength components and temperature components) of the applied heat. The hollow ceramics 31 of a certain metal oxide converts the heat of a certain component into far-infrared rays, and the hollow ceramics 31 of another type of metal oxide converts the heat of another component into far-infrared rays.

[0121] In this way, by having the hollow ceramics 31 composed of a plurality of types of metal oxides form the coating layer 3, the applied heat can be uniformly and surely converted into far-infrared rays. The far-infrared rays after this conversion are radiated, and the combustion due to heat can be surely delayed.

[0122] (Thickness of the coating layer) (Thickness from the perspective of coating formation of the coating layer 3)

[0123] The coating layer 3 is formed by applying a coating material, which is a coating agent, to the surface of the wooden base material 2 or the like. The amount of the coating material to be applied is preferably in the following range per unit area of the wooden base material 2. Weight of the coating material to be applied 150 g~280 g / m 2

[0124] It is preferable that a coating material with a weight in this range per unit area is applied to the surface of the wooden base material 2 or the like to form the coating layer 3 (the coating layer 3 is formed by applying and drying the coating material). That is, the thickness of the coating layer 3 is defined by the weight of the coating material applied per unit area.

[0125] By setting the thickness of the coating layer 3 according to this definition, conversion and radiation into far-infrared rays sufficient to delay combustion are achieved. Also, when it is too thick, the air contained in the hollow ceramics 31 has a heat-insulating effect. Therefore, if the thickness of the coating layer 3 becomes thicker than this, the total amount of this heat-insulating effect may become too large and may impair the habitability inside the building, etc.

[0126] From these facts, it may be possible to set the lower limit and upper limit of the weight as described above.

[0127] (Thickness from the perspective of the coating layer formed after drying) When the coating material applied with the above weight per unit area dries, the thickness of the coating layer becomes 154 μm or more and 291 μm or less. Defining the thickness from such a perspective is also suitable. With this thickness, a sufficient level of fire resistance can be ensured. If it is thinner than 154 μm, the conversion and radiation into far-infrared rays sufficient to delay combustion become insufficient. If it is thicker than 291 μm, there are demerits such as demerits in terms of cost and difficulty in radiating the converted far-infrared rays.

[0128] Therefore, it is preferable that the thickness is within this range.

[0129] Note that the air contained in the hollow ceramics 31 has a heat-insulating effect. Therefore, if the thickness of the coating layer 3 becomes thicker than this, the total amount of this heat-insulating effect may become too large and may impair the habitability inside the building, etc.

[0130] Therefore, it is preferable that the thickness of the coating layer is about this.

[0131] In particular, when forming the coating layer 3 by applying the coating material, it is necessary to apply an appropriate amount of the coating material. From this necessary amount of application, the above thickness is derived.

[0132] (Building) By using the fire-resistant wooden building member 1 described in Embodiments 1 and 2, a wooden building (including a building with only a part of the wooden part) is constructed. Such a building uses the fire-resistant wooden building member 1 where necessary. For example, it is used for wall materials, columns, etc.

[0133] By using the fire-resistant wooden detection member 1 for these parts, even if a fire breaks out in the building, its combustion can be delayed, and appropriate evacuation and fire extinguishing can be realized. Thereby, a wooden building with high fire resistance can be realized. As described above, the fire resistance in a wooden building (the same applies to other buildings) does not mean that it does not burn at all, but rather that the combustion is sufficiently delayed. This is because if the combustion can be delayed, evacuation and fire extinguishing can be realized.

[0134] To make a wooden building not burn at all (or approach this state), it is necessary to combine a flame-retardant material on the surface or inside of the wooden building member. This will increase the weight of the wooden building member and also increase the construction cost including foundation work.

[0135] Since the fire-resistant wooden building member 1 of the present invention only has a very thin coating layer 3, there is almost no increase in weight. Therefore, it is possible to suppress an increase in construction cost. As a result, it is also possible to widely spread wooden buildings that meet the fire resistance standards. If so, the unused forest resources in Japan can be utilized, which also leads to the protection of forests in Japan.

[0136] (Embodiment 3)

[0137] Next, Embodiment 3 will be described. In Embodiment 3, the experimental results of the fire resistance ability of the fire-resistant wooden building member will be described.

[0138] The experiment fixes a wooden building member without a coating layer and a wooden building member with a coating layer (including variations in the formation of the coating layer), and applies fire from one side with a gas burner at 850 °C to 1000 °C. That is, fire is applied from one side to cause combustion. In this state, two measurements were carried out: (1) measuring the temperature rise on the reverse side (non-combustion surface), and (2) measuring the time until it burns through.

[0139] Figure 8 is a photograph showing the state of conducting the fire resistance experiment. Figure 8 is a photograph showing the overall experimental state. Figure 9 is a photograph showing the measurement of the temperature of the combustion surface where heat (flame) is applied to the wooden building member, which is the object, by a burner in the fire resistance experiment. Figure 10 is a photograph showing the state of measuring the temperature of the non-combustion surface on the reverse side.

[0140] As shown in Figures 8 and 9, fix and set the wooden building member. Apply fire from one side with a gas burner at 850 °C to 1000 °C. That is, one side becomes the combustion surface. By continuously applying fire to the combustion surface, the temperature of the wooden building member rises and it can be burned. The temperature rise due to the progress of this combustion is also transmitted to the non-combustion surface on the reverse side.

[0141] As shown in Figure 9, it can be seen that 954 °C of heat is being applied to the combustion surface. Due to such application of heat, the combustion of the wooden building member progresses. Heat is transmitted to the inside of the wooden building member, and the temperature of the non-combustion surface on the reverse side also rises. Figure 10 shows the state of measuring the temperature rise of this non-combustion surface.

[0142] Also, as shown in Figure 10, the temperature rise is measured in conjunction with the passage of time from the start of combustion. Thus, the following two points are being measured as described above.

[0143] (1) Measure the temperature rise on the reverse side (non-combustion surface) (2) Measure the time until it burns through

[0144] By measuring these two points, the required fire resistance can be confirmed. As described above, the fire resistance of wooden building members does not mean that they do not burn at all, but rather that sufficient time is ensured until they burn out. That is, it is sufficient if (1) the temperature rise is suppressed and (2) there is sufficient time until they burn out.

[0145] Figure 11 is a graph showing the experimental results.

[0146] In the experiment, wooden building members with different coating layers were used as samples for the first to fifth times, and the experiment was conducted by the method shown in Figures 8 to 10. All samples from the first to fifth times used a 15-mm-thick sugi board as the wooden base material.

[0147] First sample: Only the wooden base material of a 15-mm sugi board. There is no coating layer (comparative example)

[0148] Second sample: A fire-resistant wooden building member with a coating layer formed by applying a coating material twice only on the heated surface of the wooden base material of a 15-mm sugi board. There is no coating layer on the unheated surface.

[0149] Third sample: A fire-resistant wooden building member with a coating layer formed by applying a coating material twice only on the unheated surface of the wooden base material of a 15-mm sugi board. There is no coating layer on the heated surface.

[0150] Fourth sample: The same as the third sample

[0151] Fifth sample: A wooden building member with a coating layer formed by applying a coating agent once on the heated surface of a 15-mm sugi board wooden base material and applying the coating agent twice on the unheated surface to form a coating layer.

[0152] The experimental results in Figure 11 are as follows.

[0153] First sample: The wooden building member without a coating layer rose to 150°C in about 10 minutes, and when the heated surface was exposed to flames, it burned out to the unheated surface. Naturally, this is insufficient.

[0154] Second sample: It rises to 280°C in about 15 minutes. Also, the temperature rise 10 minutes after the first sample burned out is 150°C, which is about the same. However, the endurance time until it burns out is 15 minutes, and compared to the first wooden building member, the fire resistance time has been improved by more than 50%. Therefore, it was confirmed that the fire resistance ability has been improved.

[0155] Third sample: The time until it burns out is about 24 minutes, which is nearly 2.5 times that of the first sample, and it was confirmed that the fire resistance ability has been sufficiently improved. Also, the temperature rise 24 minutes after it burns out is 200°C or less, and the temperature rise is suppressed including the temperature rise curve. In particular, due to the suppression of the rise curve, even if a fire breaks out in a building where wooden building members are used, it can protect the people inside and ensure sufficient evacuation time until the fire is extinguished.

[0156] Fourth sample: The time until it burns out is about 30 minutes, and the fire resistance ability and fire resistance time are further improved. The temperature rise curve is the same as that of the third sample.

[0157] Fifth sample: The time until it burns out is nearly 40 minutes, and the fire resistance ability and fire resistance time are further improved. The temperature rise curve is the same as that of the third sample.

[0158] In the second to fifth samples, which are fire-resistant wooden building members with a coating layer formed, the fire resistance time, fire resistance ability, and temperature rise are all improved. As a result, it was confirmed that the required fire resistance ability is provided.

[0159] Also, even if a fire breaks out in a building where these fire-resistant wooden building members are used, they can protect the people inside and ensure sufficient evacuation time until the fire is extinguished.

[0160] As described above, the effect of the fire-resistant wooden building member of the present invention was also confirmed from the actual fire resistance experiment.

[0161] The fire-resistant wooden building members described in the above Embodiments 1 to 3 are examples for explaining the gist of the present invention, and include modifications and alterations within the scope not departing from the gist of the present invention.

Explanation of Signs

[0162] 1 Fire-resistant wooden building member 2 Wooden base material 3 Coating layer 31 Hollow ceramics 32 Resin binder 310 Internal space 311 First ceramic layer 312 Second ceramic layer 313 Third ceramic layer

Claims

Claim 1. A fire-resistant wooden building member having fire resistance, comprising: a wooden base material; a coating layer formed on at least a part of the front surface, back surface and side surfaces of the wooden base material, wherein the coating layer includes a plurality of hollow ceramics; and a resin binder connecting the plurality of hollow ceramics to each other, and has the coating layer converts heat applied to at least one of the wooden base material and the coating layer into far-infrared rays and radiates the far-infrared rays, the plurality of hollow ceramics include hollow ceramics having a plurality of different particle sizes, the wooden base material is a wall material, the particle size of the plurality of hollow ceramics is 10 μm to 150 μm, the average particle size of the plurality of hollow ceramics is 40 μm, the particle size of the plurality of hollow ceramics includes those having a particle size of 10 μm and those having a particle size of 150 μm, and the hollow ceramics having a particle size of 10 μm enter into the gaps formed between the hollow ceramics having a particle size of 150 μm, the hollow ceramics have an outer surface and an internal space, at least one of the conversion of heat into far-infrared rays on the outer surface and the conversion of heat into far-infrared rays by diffuse reflection in the internal space, the heat applied to at least one of the wooden base material and the coating layer is converted into far-infrared rays, the plurality of hollow ceramics form a plurality of ceramic layers made of hollow ceramics having different main particle sizes in the coating layer, each of the plurality of ceramic layers radiates far-infrared rays obtained by converting the applied heat, by the radiation of far-infrared rays by the coating layer, it is possible to suppress the temperature rise of the wooden base material due to the heat applied to the fire-resistant wooden building member, the thickness of the coating layer is defined as follows in terms of the weight of the coating material forming the coating layer per unit area of the wooden base material: Weight of the coating material: 150 g to 280 g / m 2 (per unit area of the wooden base material) and is defined by the thickness of the coating layer formed after drying the coating material is 154 μm or more and 291 μm or less, a fire-resistant wooden building member. Claim 2 The fire-resistant wooden building member according to claim 1, wherein the hollow ceramics contain a metal oxide. Claim 3 The metal oxide is aluminum oxide (Al ２ O ３ ), magnesium oxide (MgO), ferric oxide (Fe2O3), sodium oxide (Na ２ O), potassium oxide (K ２ O), titanium oxide (TiO ２ ), cerium oxide (CeO ２ ), silicon dioxide (SiO ２ ), antimony trioxide (Sb ２ O ３ ), and the refractory wooden building member according to claim 2, containing at least one of them. Claim 4 The fire-resistant wooden building member according to claim 3, wherein the coating layer includes the hollow ceramics made of two or more types of the metal oxides. Claim 5 The fire-resistant wooden building member according to any one of claims 1 to 4, wherein the resin binder is an acrylic resin. Claim 6 A building constructed using the fire-resistant wooden building member according to any one of claims 1 to 5.

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