Composition for structure, structure, and method for manufacturing structure

Abstract

To provide a wooden building 2-hour fireproof structure having good processing moldability, safety after pulverization, waterproofness, fire resistance, flame retardancy and the like from a safe material which is inexpensive and not harmful to a human body.SOLUTION: Provided are: a composition for a structure containing (A) inorganic powder with an average particle size of 500 μm or less or wood powder with an average particle size of 212 μm or less, (B) a room-temperature curing binder containing water glass and silica powder having an average particle diameter of 5 nm or less, and (C) a solvent; and a structure for molding and curing the composition for the structure.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a structural composition, a structure, and a method for manufacturing a structure, and more particularly to a structural composition, a structure, and a method for manufacturing a structure, which are capable of forming a wooden building with excellent recyclability. [Background technology]

[0002] In the case of members that support vertical loads, such as columns and beams in wooden buildings, fire-resistant construction is required to have the ability to prevent the spread and collapse of the building until the fire is extinguished, both in the case of normal fires that are expected to occur outdoors and normal fires that are expected to occur indoors, and performance is set at 30 minutes, 1 hour, 2 hours, or 3 hours depending on the member and number of floors. In tests to obtain Ministerial Certification of fire-resistant construction under the Building Standards Act, it is required that the fire should stop naturally without risk of re-ignition after heating has ended, and the current evaluation does not allow structural wood to char until the end of the test.

[0003] Certified types of wood-based fire-resistant construction are broadly classified into "covered type," in which the wooden parts are covered with a fire-resistant coating such as reinforced gypsum board; "flame-stopping type," in which a fire-stopping layer is provided to stop the combustion midway so that the wood in the load-bearing parts does not burn; and "steel-frame built-in type," in which the steel frame is covered with fire-resistant wood to stop the wood combustion midway and suppress the rise in the steel frame temperature. However, there are disadvantages to the "covered type," in that the wood is not exposed, the "flame-stopping type" is complicated to manufacture (for example, the fire-stopping layer needs to be flame-retardant), and the "steel-frame built-in type" is currently limited in the types of materials that can be used. Currently, simple two-hour fire-resistant construction for wooden buildings mainly uses three layers of fire-resistant gypsum board, 64 mm thick. Gypsum board is inexpensive, but there are risks involved when disposing of it. Specifically, for example, there is a risk that materials that have been treated as industrial waste and buried underground may generate hydrogen sulfide under certain conditions (the presence of sulfate-reducing bacteria, the presence of organic matter that serves as a carbon source for sulfate-reducing bacteria, the retention of moisture appropriate for the proliferation of sulfate-reducing bacteria, etc.) Even if they are recycled, these problems have not been completely resolved.

[0004] So, one idea for reducing the large amount of waste from used structures is to think not about how to dispose of them, but to turn the structures themselves, which are the entry point into the waste, into environmentally friendly recyclable materials, thereby reducing the amount of waste from used structures and solving the garbage problem.

[0005] One method for utilizing recyclable materials is to crush used structures and reshape them. To use them in this way, the structures must be low-cost, have good moldability, and be safe after crushing.

[0006] As a method for using used structures after crushing, an organic-inorganic composite composition is considered. The organic-inorganic composite composition (Patent Document 1) proposed as an organic-inorganic composite composition is an organic-inorganic composite composition in which silica particles are finely and substantially uniformly dispersed in an organic synthetic resin, and is characterized in that it is obtained by mixing water glass into an aqueous emulsion of the organic synthetic resin, and further adding an acid to aggregate the organic synthetic resin and silica sol (Claim 1 of Patent Document 1, etc.).

[0007] However, this organic-inorganic composite composition has the drawback that it cannot be molded at room temperature or low temperature because silica particles are finely and uniformly dispersed in order to improve the properties of organic synthetic resins such as thermoplastic resins (Patent Document 1, paragraph 0001).In addition, the use of resin makes it difficult to use in terms of fire resistance. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2008-101049 A Summary of the Invention [Problem to be solved by the invention]

[0009] The object of the present invention is to provide a structural composition which is inexpensive and capable of forming structures having good processability and formability, safety after crushing, and furthermore, lightweight, waterproofness, fire resistance, etc., from safe materials which are not harmful to the human body, and to obtain structural materials for wooden buildings which are easy to recycle, easy to process, and have fire resistance. [Means for solving the problem]

[0010] The present invention relates to a composition for a structure, a structure, and a method for producing a structure, which have the following features and thereby solve the above problems. [1] (A) an inorganic powder having an average particle size of 500 μm or less and a wood powder having an average particle size of 212 μm or less; (B) a room temperature curing binder containing water glass and silica powder with an average particle size of 10 nm or less; (C) a solvent; A composition for a 2-hour fire-resistant structure, comprising: [2] A structure which is a cured product of the structural composition described in [1] above. [3] The structure according to the above [2], having a thickness of 3 to 300 mm. [4] A structure having two or more types of the structure described in [2] or [3] above, and having a fire resistance of 2 hours or more. [5] A method for producing a structure, comprising curing the structure composition described in [1] above. [6] The method for producing the structure according to the above [5], wherein the curing is carried out at 0 to 40°C. [7] A method for producing a structure having a fire resistance of 2 hours or more, comprising injecting the structural composition described in [1] above into a plastic mold, hardening the composition, and then removing the composition from the plastic mold. [8] A method for producing a structure having a fire resistance of 2 hours or more, comprising bonding the structure having a fire resistance of 2 hours or more described in [4] above with a fire-resistant adhesive. Effect of the Invention

[0011] According to the present invention [1], it is possible to provide a low-cost composition for structures that can be formed from safe materials that are not harmful to the human body, and that have good processability, safety after crushing, and furthermore, lightweight, waterproof, fireproof, and flame-retardant properties.

[0012] According to the present invention [4], it is possible to provide a structure having good processability, safety after crushing, and further having light weight, waterproofness, and fire resistance, and having a fire resistance of 2 hours or more.

[0013] According to the present invention [5], a structure having low cost, good processability, safety after crushing, light weight, waterproofness, and a predetermined fire resistance can be produced inexpensively and easily. [Brief description of the drawings]

[0014] [Figure 1] This is an explanatory diagram of a simple test for examining 2-hour fire resistance. [Diagram 2] FIG. 2 is an explanatory diagram of an area where an interlayer adhesive and a joint adhesive are used. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] [Structure composition] The structural composition of the present invention (hereinafter referred to as the composition) is (A) an inorganic powder having an average particle size of 500 μm or less or a wood powder having an average particle size of 212 microns or less; (B) a room temperature curing binder containing water glass and silica powder with an average particle size of 10 nm or less; (C) a solvent; This composition makes it possible to provide a structural composition capable of forming a structure having good processability, safety after crushing, and furthermore, light weight, waterproofness, fire resistance, flame retardancy, etc., from a low-cost and safe material. Here, fire resistance performance is the performance required for a part of a building to prevent the collapse and spread of the building due to a normal fire until the fire is extinguished, and in the case of a 2-hour fire-resistant structure, it means that after 2 hours of heating in a fire-resistant furnace according to a heating curve (ISO834), the fire-resistant coating layer of the member completely stops burning by itself within 24 hours after leaving it in the fire-resistant furnace, and the structural part (wooden structural support member) is not damaged (non-carbonized).

[0016] From the viewpoint of reducing weight, the shape of the inorganic powder having an average particle size of 500 μm or less, which is component (A), is preferably hollow bead-like. From the viewpoint of fire resistance, the material used is preferably ceramic such as pottery. If reducing weight is not required, solid powder such as pottery, which has been used for a long time, can be used. Examples of inorganic powders that can be used include pottery powder, shell powder, coral powder, rice husk (rice husk) powder, metal powder, etc. Also, as for wood flour powder, wood flour having self-extinguishing properties is preferred. Average particle size A size of 212μ or less is preferred, and here, wood flour powder with an average particle size of 212μm or less is a powder that has passed through a sieve with a nominal mesh size of 212μm. The average particle size of the inorganic powder or wood flour powder of component (A) is preferably 100μm or less, more preferably 50μm or less, and even more preferably 10μm or less. It is preferable to include ceramic hollow beads (e.g., B-05, W-3, etc., manufactured by Showa Chemical Industry Co., Ltd.) because it is possible to suppress shrinkage during curing, to reduce weight, and to reduce the thermal conductivity of the structure. In addition, when the ceramic hollow beads are added to the composition, it is possible to make the ceramic hollow beads less likely to be crushed and to increase the compressive strength.

[0017] The component (A) may be used alone or in combination of two or more kinds.

[0018] Component (B) is a room temperature curing binder containing water glass and silica powder with an average particle size of 10 nm or less. If the average particle size of the silica powder is 10 nm or more, it is difficult to cure in a room temperature environment, so one with an average particle size of 10 nm or less is used here. Here, room temperature refers to a range of 0 to 40°C. By being able to cure the structure in a room temperature environment, it is possible to improve the workability of the fire-resistant building material. The water glass is a concentrated solution of an alkali silicate, and is not particularly limited, and examples thereof include sodium silicate and lithium silicate. One example is Na 2 O: 1 mol per SiO 2 It is a colorless, highly viscous aqueous solution containing 2 to 4 mol of silica. A commercially available product can be used for this water glass. For example, a mixture of lithium silicate and sodium silicate can be used for this water glass. The water glass may be used alone or in a mixture of two or more types. An example of a silica powder having an average particle size of 10 nm or less is dry silica powder manufactured by Tokuyama Corporation (product name: Reoloseal (registered trademark) QS-30, a powder having an average primary particle size of 7 nm). The silica powder may be used alone or in a mixture of two or more types. An example of a commercially available product of component (B) is room temperature curing waterproof flame retardant binder BW-35 manufactured by Japan Nano Coat Co., Ltd. (average particle size of silica: 7 nm; pure water: 65 to 70 wt%, sodium silicate + lithium silicate: Na 2 O: 2-8wt% + Li 2 O: 1-3%, SiO 2 The average particle size is a value based on the number of particles measured by dynamic light scattering using a ZETASIZER (registered trademark)-nano manufactured by Malvern Panalytical. The amount of water glass is preferably 40 to 90 parts by mass in 100 parts by mass of component (B).

[0019] The amount of (A) inorganic powder having an average particle size of 500 μm or less is preferably 10 to 60 parts by mass, and more preferably 30 to 50 parts by mass, per 100 parts by mass of the composition. The amount of (A) wood flour powder having an average particle size of 212 μm or less is preferably 10 to 30 parts by mass, and more preferably 12 to 20 parts by mass, per 100 parts by mass of the composition.

[0020] When component (B) is binder BW-35 manufactured by Japan Nano Coat Co., Ltd., the amount is preferably 40 to 90 parts by mass, and more preferably 40 to 50 parts by mass, per 100 parts by mass of the composition. If component (B) exceeds 90 parts by mass, the composition has a low viscosity and is difficult to form, and if it is less than 40 parts by mass, the composition cannot be held and molded.

[0021] The solvent (C) is used in an amount of 0.1 to 10 parts by mass to adjust the viscosity of the composition when dried. From the viewpoint of the drying speed after application, the solvent used is preferably water (pure). Optionally, a small amount of a high boiling point solvent such as a glycol may be added.

[0022] If necessary, additives such as a flame retardant auxiliary can be further added to the composition within the scope of the present invention.

[0023] The composition can be obtained, for example, by stirring, melting, mixing, and dispersing various materials, solvents, and other additives, simultaneously or separately, while adding heat treatment as necessary. The device for mixing, stirring, dispersing, etc. is not particularly limited, but a propeller stirrer, a jet mill, an anchor type stirrer, a mortar mixer, a ball mill, a planetary mixer, a bead mill, etc. can be used. These devices may also be used in appropriate combination. When hollow beads are used, a device that does not crush the beads is preferable.

[0024] Since the composition of the present invention has good releasability from a plastic mold, it can be molded using a plastic mold that is inexpensive and easy to make. Of course, it can also be molded by hand like clay.

[0025] In addition, for component (A), in the case of inorganic powder, naturally occurring shells, ash, etc. may be used. Therefore, since the materials for component (A), both inorganic powder and wood powder, are found all over the world, it is very easy to procure the materials.

[0026] [Structure] (A) an inorganic powder having an average particle size of 500 μm or less or a wood powder having an average particle size of 212 μm or less; (B) a room temperature curing binder containing water glass and silica powder with an average particle size of 10 nm or less; (C) Solvent and The structural composition comprising the above component (A) is cured.

[0027] This structure can be used not only as a fire-resistant member, but also as a structural member and as an interior and exterior building material.

[0028] This structure exhibits remarkable effects, particularly when hollow beads are used as the component (A) in addition to inorganic powder having an average particle size of 500 μm or less, that is very lightweight, has a heat insulating and sound absorbing effect, and can be manufactured inexpensively due to the bulking effect. In addition, the structure can be recycled by crushing it into powder of an appropriate size and using it, so that it is suitable for a recycling-oriented society. The preferred thickness of one structure is 3 to 300 mm. If it is thinner than 3 mm, it is easy to deform when dried, and if it is thicker than 300 mm, it takes time to mold and is easy to collapse. In order to form a structure having a fire resistance of 2 hours or more using this structure, it is preferable to combine two or more layers of this structure. The thickness of the structure that is considered to have a predetermined fire resistance after performing a simple fire resistance test for 2 hours is 550 to 700 mm. The specific structure will be described in Examples 1 to 4 described later.

[0029] [Method for manufacturing the structure] The method for producing a structure of the present invention is a method for curing the above-mentioned structural composition, and the curing is preferably carried out at 0 to 40° C. A more characteristic method for producing a structure of the present invention is a method in which the above-mentioned structural composition is injected into a plastic mold, cured, and then removed from the plastic mold.

[0030] The above-mentioned structural composition has releasability from a plastic mold. The above-mentioned structural composition can be cured by drying at room temperature or at a low temperature of 100°C or less, so that the manufacturing cost can be reduced. In addition, a manufacturing method of a structure having a fire resistance of 2 hours or more, in which structures having a fire resistance of 2 hours or more are bonded together with an adhesive, is also preferred.

[0031] Plastic molds can be easily made using a three-dimensional printer or the like, and therefore can be produced inexpensively. In addition, the curing temperature of the above-mentioned structural composition is low, so the mold is less likely to deteriorate. EXAMPLES

[0032] The present invention will be described with reference to examples, but the present invention is not limited thereto. In the following examples, parts and % indicate parts by mass and % by mass, unless otherwise specified.

[0033] (A) For the inorganic powder having an average particle size of 500 μm or less, B-05 manufactured by Showa Chemical Industry Co., Ltd. was used. B-05 manufactured by Showa Chemical Industry Co., Ltd. is a hollow ceramic bead. Moreover, instead of inorganic powder, wood powder with an average particle size of 212 microns or less was used. (B) BW-35 manufactured by Japan Nano Coat Co., Ltd. was used as the binder. (C) Pure water was used as the solvent.

[0034] <2-hour simple fire resistance test> In the following, a 2-hour fire-resistant structure is placed in a fire-resistant furnace according to the heating curve (compliant with ISO834) and left in the furnace for 2 hours. If the fire-resistant coating layer of the components has completely stopped burning by itself within 24 hours and the structural parts (wooden structural support components) are not damaged (not carbonized), then the structure is deemed to have passed the test (however, this does not mean that the structure has passed the certification test as a fire-resistant structure).

[0035] [ reference Example 1 A composition was prepared by mixing 40 parts by mass of ceramic hollow beads (B-05 manufactured by Showa Chemical Industry Co., Ltd.) and 60 parts by mass of BW-35 manufactured by Japan Nano Coat Co., Ltd. The composition was molded to prepare a structure with a thickness of 300 mm. Figures 1 and 2 show explanatory diagrams of the 2-hour fire resistance test. The central figure in Figure 1 shows an overall view of the model test specimen. The right side of Figure 1 is a top view seen from the height of a at the top of the central figure, and the left side of Figure 1 is a cross-sectional view at half height in the height direction of the cedar laminated timber indicated by the thick dot in the central figure. Figure 2 corresponds to b.sec in Figure 1 and shows the area where the interlayer adhesive and joint adhesive were used. As can be seen from Figure 1, the upper and lower surfaces of the cedar laminated timber pillar are sandwiched between calcium silicate boards, and the temperature was measured at approximately the center in the height direction. As can be seen from Figure 2, the four sides of the cedar laminated timber pillar were glued with eight structural members (two structural members for each side of the cedar laminated timber). The dashed and dotted lines in Figure 2 indicate the areas where interlayer adhesive was used, and the dashed lines indicate the areas where joint adhesive was used. An interlayer adhesive was used to bond the large surfaces of the cedar laminated timber and the structural member, and a joint adhesive was used to bond the end faces of the structural member. The joint adhesive was used to bond the cedar laminated timber so that heat from the calcium silicate boards sandwiched above and below would not easily reach the cedar laminated timber. For example, Nichias Corporation's Insulation Adhesive can be used as the interlayer adhesive, and AS Bond can be used as the joint adhesive.

[0036] Two structural members were used on each side of a 120 mm x 120 mm x 300 mm cedar laminated lumber, covering the entire surface with a total thickness of 600 mm. Example 1 passed the two-hour simplified fire resistance test.

[0037] Example 2 A composition was prepared by mixing 13 parts by mass of wood powder with a particle size of 212 μm or less and 87 parts by mass of BW-35 manufactured by Japan Nano Coat Co., Ltd. The composition was molded to prepare a structure with a thickness of 300 mm. As in Example 1, two structures were used on each side of a 120 mm x 120 mm x 300 mm cedar laminated timber, covering the structure with a total thickness of 600 mm. Example 2 passed the two-hour simplified fire resistance test.

[0038] Comparative Example 1 Instead of the structure, 8 pieces of 120mm thick fire-retardant treated wood were used per side of a 120mm x 120mm x 300mm cedar laminated timber, with a total thickness of 960mm, to cover the cedar laminated timber. Tests were conducted in the same manner as in Example 1 for the rest of the structure, but the 2-hour simplified fire resistance test was not passed.

[0039] Comparative Example 2 reference Instead of one sheet of the outer structure of Example 1, two sheets of 120mm thick fire-retardant treated cedar laminated lumber are used. reference Combined with the 300mm structure of Example 1, the total thickness was 540mm, and the cedar laminated timber was covered. reference The test was carried out in the same manner as in Example 1, but the product did not pass the two-hour simplified fire resistance test.

[0040] Comparative Example 3 reference Instead of one outer structure of Example 1, one oak board of 250mm thickness is used. reference Combined with the 300mm structure of Example 1, the cedar laminated timber was covered with a total thickness of 550mm. reference The test was carried out in the same manner as in Example 1, but the product did not pass the two-hour simplified fire resistance test.

[0041] Example 3 reference Instead of the single outer structure of Example 1, a 250 mm thick silica (SiO 2 ) and alumina (Al 2 O 3 ) is the main component of the ceramic wool board, referenceThis was combined with the 300 mm thick structure of Example 1, and the cedar laminated timber was covered to a total thickness of 550 mm. reference Example 3 passed the two-hour simplified fire resistance test.

[0042] Comparative Example 4 reference Instead of one of the outer structures in Example 1, a single 250mm thick board made of fibrous basalt, silica, blast furnace slag, and other main raw materials was used. reference Combined with 300 mm of the structure of Example 1, the total thickness was 550 mm, and the cedar laminated timber was covered. It did not pass the two-hour simple fire resistance test.

[0043] Example 4 reference Instead of one outer structure of Example 1, one structure of Example 2 with a thickness of 150 mm was used, and one ceramic wool structure of Example 3 with a thickness of 250 mm was combined on the outside of that, resulting in a total thickness of 700 mm, covering the cedar laminated wood. Example 4 passed the two-hour simple fire resistance test.

[0044] Comparative Example 5 reference Although the component (B) in Example 1 was changed to an aqueous sodium silicate solution (sodium silicate No. 3) manufactured by Fuji Chemical Co., Ltd. and the other conditions were the same, molding did not go well.

[0045] Comparative Example 6 reference Although the component (B) in Example 1 was changed to Nissan Chemical Lithium Silicate Aqueous Solution 45 and the other conditions were the same, molding did not go well.

[0046] Comparative Example 7 reference A composition was created in which component (A) of Example 1 was sieved through a 500 μm sieve using Showa Chemical Industry Co., Ltd.'s B-03 to make all hollow beads sized at 500 μm or more, and the rest of the conditions were the same as in Example 1. However, as a preliminary test, the molded product melted in an electric furnace at 1000°C, so it was not possible to create a composition that satisfied the conditions of this test.

[0047] Comparative Example 8 reference Although the component (B) in Example 1 was changed to Snowtex (registered trademark) ST-C (average particle size: 12 nm) manufactured by Nissan Chemical Industries, Ltd. and the other conditions were the same as those in Example 1, molding was not successful.

[0048] Comparative Example 9 A composition was created using component (A) of Example 2, with all wood flour particles having a size of 212 μm or more, and testing was performed under the same conditions as in Example 2. However, preliminary testing showed that the wood flour itself ignited, and it was not possible to create a composition that satisfied the conditions of this test. [Industrial Applicability]

[0049] The structural composition of the present invention can form a wooden building structure having a fire resistance of 2 hours or more, and the formed structure can be used as a structural member, interior material, exterior material, or other building material.

Claims

[Claim 1] (A) wood flour powder having an average particle size of 212 μm or less; (B) a room temperature curing binder containing water glass and silica powder having an average particle size of 10 nm or less; (C) a solvent; and A structure in which a composition comprising the above is cured in a room temperature environment, The thickness of the structure is 150 to 300 mm; A structure comprising two or more sheets of the structure bonded together with a fire-resistant adhesive.

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