Flat deck, fire compartment structure and flat deck manufacturing method

Abstract

To provide a flat deck, a fireproof partitioned structure, and a production method of the flat deck excellent in a fireproof property as well as allowing connection using ribs.SOLUTION: A flat deck 1 of the present invention is provided with a flat part 11, ribs 12 (121), 122) projected from one 11D of surfaces of the flat part 11, and filler 13 placed inside of the ribs 12, wherein the rib 12 comprises a cavity part 12a having a cavity thereinside, and a connection part 12b connecting the cavity part 12a and the one 11D of surfaces, and the filler 13 is filled inside of the cavity part 12a so as not to be filled in a part of the connection part 12b.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a flat deck used in a building structure, a fire compartment structure, and a method for manufacturing a flat deck. [Background technology]

[0002] Conventionally, flat decks have been used to construct floor or roof structures of building structures such as reinforced concrete and steel-reinforced concrete. A flat deck has a plurality of ribs extending in the longitudinal direction and having internal cavities formed on the underside of the flat portion, and has a flat upper surface (see, for example, Patent Document 1). In floor or roof structures, flat decks are used, for example, as formwork material for pouring concrete onto the upper surface of the flat portion.

[0003] In architectural structures, fire compartment structures are often formed using facing materials such as gypsum board. To prevent the spread of flames in the event of a fire and to ensure sound insulation and thermal insulation in compartments other than the fire compartment structure, it is necessary to eliminate gaps between the fire compartment structure and the floor structure or roof structure. For example, if a flat deck is installed on the floor structure, when a partition material for forming a compartment such as a fire compartment structure is butted against its underside, gaps will form between the floor structure and the partition material due to the cavities inside the ribs. Therefore, in the area where the partition material butts, the ribs must be removed by cutting the flat deck, for example. The rib removal work is usually performed on-site after the concrete has been poured. Removing the ribs on the construction site is time-consuming and poses safety issues.

[0004] To solve this problem, a flat deck with ribs filled with filler has been proposed. When the flat deck is filled with filler, the cavities inside the ribs prevent gaps from forming between the floor structure and the partition material, making it possible to omit the work of removing the ribs. Furthermore, when constructing a plurality of flat decks side by side, it is known to connect the flat decks by inserting claws provided at the ends of the flat decks into the ribs of adjacent flat decks. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-110453 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in flat decks with ribs filled with filler, the claws cannot be inserted properly due to the filler, making it impossible to connect the flat decks using the ribs, making installation difficult.

[0007] Therefore, the present invention can provide a flat deck, a fire compartment structure, and a method for manufacturing a flat deck that can be connected using ribs and has excellent fire resistance. [Means for solving the problem]

[0008] The gist of the present invention is as follows. [1] A flat deck comprising a flat portion, a rib protruding from one surface of the flat portion, and a filler provided inside the rib, wherein the rib has a hollow portion with a cavity inside and a connecting portion connecting the hollow portion to the one surface, and the filler is filled inside the hollow portion so as not to fill at least a portion of the connecting portion. [2] A flat deck as described in [1], in which the connecting portion can fit into the claw portion of an adjacent flat deck. [3] A flat deck according to [1] or [2], wherein the filling is a foam. [4] The flat deck according to any one of [1] to [3], wherein the filler is an organic foam. [5] The flat deck described in [4], wherein the organic foam is urethane foam. [6] The density of the packing is 10 kg / m 3 More than 200kg / m 3 A flat deck according to any one of [1] to [5] below. [7] The filling material has a radiant heat intensity of 50 kW / m in a heat generation test using a cone calorimeter in accordance with ISO 5660-1. 2 The total heat generation amount for 20 minutes after the start of heating is 8MJ / m 2 A flat deck according to any one of [1] to [6] below. [8] The flat deck according to any one of [1] to [7], wherein the rib has an injection port at the bottom for injecting the filling material. [9] A fire compartment structure comprising a flat deck according to any one of [1] to [8] and a non-combustible material filling the spaces between the ribs on one side of the flat portion of the flat deck.

[10] A method for manufacturing a flat deck comprising a flat portion, a rib protruding from one surface of the flat portion, and a filler provided inside the rib, wherein the rib has a hollow portion with a cavity inside and a connecting portion connecting the hollow portion to the one surface, the method comprising a step of eliminating at least some of the gaps in the connecting portion and filling the filler inside the rib. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a flat deck, a fire compartment structure, and a method for manufacturing a flat deck that can be connected using ribs and has excellent fire resistance. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1(a) is a plan view showing a flat deck according to an embodiment of the present invention, and FIG. 1(b) is a cross-sectional view taken along the line AA in FIG. 1(a). [Figure 2] FIG. 3 is a cross-sectional view showing a connected state of the flat deck according to the embodiment of the present invention. [Figure 3] 1A to 1C are perspective views showing steps in a first manufacturing method of a flat deck according to an embodiment of the present invention. [Figure 4] 5A to 5C are perspective views showing steps in a second manufacturing method of a flat deck according to an embodiment of the present invention. [Figure 5] 1 is a cross-sectional view showing a fire compartment structure according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] As shown in Figures 1(a) and (b), the flat deck 1 according to an embodiment of the present invention comprises a flat portion 11, ribs 12 (121, 122) protruding from one surface 11D of the flat portion 11 and having a hollow space therein, and a filler 13 provided inside the rib 12.

[0012] The flat deck 1 has a flat portion 11 having an upper surface 11U that is flat or has minute irregularities formed thereon, and a lower surface 11D of the flat portion 11 from which a plurality of ribs 121, 122 protrude. The ribs 121, 122 are arranged in the horizontal direction (the X-axis direction in FIG. 1). While FIG. 1 shows an example in which two ribs are provided, the number of ribs is not particularly limited. Each of the ribs 121, 122 is a protrusion with an internal cavity and extends in the vertical direction (the Y-axis direction in FIG. 1). Both ends of each rib 12 in the longitudinal direction are configured to be closed, and can be closed by crushing, or can be configured using a closing member. The flat deck 1 can be obtained, for example, by roll forming or press forming a metal plate such as a steel plate or other material.

[0013] As shown in Figure 1(b), the cross-sectional shape of the rib 12 of the flat deck 1 includes a hollow portion 12a with a hollow formed therein and a connecting portion 12b that connects the lower surface 11D and the hollow portion 12a. The cross-sectional shape of the cavity formed by the hollow portion 12a is not particularly limited and can be various shapes such as a triangle, a rectangle, or a circle, as long as a hollow is formed inside. The connecting portion 12b is arranged so that its width narrows from the hollow portion 12a and a pair of plate-like portions meet, and each plate-like portion connects the upper end of the hollow portion 12a to the lower surface 11D.

[0014] The flat deck includes a claw portion 14 that protrudes from one surface 11D of the flat portion 11 and connects to the rib 12 of an adjacent flat deck. The claw portion 14 is provided on a side end portion 18A of the flat portion 11. The claw portion 14 is formed, for example, by bending the flat portion 11. The claw portion 14 can be fitted into the connecting portion 12b of an adjacent flat deck 1. As shown in FIG. 2, the flat deck 1 can connect adjacent flat decks 1 by inserting and fitting the claw portion 14 into the connecting portion 12b of the adjacent flat deck 1. Note that, as shown in FIG. 2, the claw portion 14 is inserted into the gap between the pair of plate-shaped portions that make up the connecting portion 12b and fitted thereto.

[0015] In this embodiment, the filler 13 is a foam. By using a foam as the filler 13, the specific gravity is reduced, and the weight of the entire building material can be reduced. The foam used for the filler 13 is preferably an organic foam. The organic foam for the filler 13 is preferably one selected from the group consisting of, for example, urethane foam, phenol foam, styrene foam, PVC foam, and polyolefin foam such as polyethylene foam, and among these, either urethane foam or phenol foam is more preferable, and urethane foam is even more preferable. Furthermore, examples of foams (inorganic foams) other than organic foams include water glass and foamed concrete.

[0016] The filler 13 is filled inside the hollow portion 12a so as not to fill at least a portion of the connecting portion 12b of the rib 121. As described below, a foam as the filler 13 is typically injected into the hollow portion 12a of the rib 121 and foamed to fill it. Therefore, when a foam is used as the filler 13, the foam fills not only the hollow portion 12a but also the gaps of the connecting portion 12b. In this embodiment, however, as described in the manufacturing method described below, the filler 13 is not filled in a portion of the gaps of the connecting portion 12b, leaving an unfilled portion 15 in the connecting portion 12b. Therefore, by fitting the claw portion 14 into the unfilled portion 15, it is possible to connect a pair of flat decks while filling the hollow portion 12a of the rib 121 with the filler 13. Therefore, the flat deck can be connected to other flat decks using the ribs and can have excellent fire resistance.

[0017] 1(b), it is preferable that the filler 13 is not filled in the entire gap of the connecting portion 12b, and that the entire gap of the connecting portion 12b is left as an unfilled portion 15. However, as long as the claw portion 14 can fit into the connecting portion 12b, the unfilled portion 15 may be a part of the gap of the connecting portion 12b of the rib 121. For example, the gap above the connecting portion 12b may be left as an unfilled portion, and the gap below may be filled with the filler 13 and left as a filled portion. 1, the claw portion 14 is generally provided in a part of the side end portion 18A of the flat portion 11 (i.e., a part in the Y-axis direction), but a part of the connecting portion 12b in the Y-axis direction may be left unfilled in accordance with the position of the claw portion 14 so that the claw portion 14 can fit in. Therefore, for example, as long as the claw portion 14 can fit in, only a part of the gap above the connecting portion 12b may be left unfilled, and the other part may be filled.

[0018] 1, of the plurality of ribs 121, 122 whose hollow portions are filled with filler, it is preferable that an unfilled portion 15, which is not filled with filler, is provided at the connecting portion 12b of at least one of the ribs 121. However, from the viewpoint of ease of manufacturing, etc., all of the ribs 121, 122 may be provided with unfilled portions 15, which are not filled with filler. Furthermore, the rib 121 on which the unfilled portion 15 is provided is preferably the rib provided closest to the side end 18B among the multiple ribs aligned in the X-axis direction of the flat deck so that the claw portion 14 can fit in. The rib provided closest to the side end 18B can easily fit in with the claw portion 14. Furthermore, when multiple flat decks 1 are connected together, the overlapping portions of the flat decks in the X-axis direction can be reduced.

[0019] Each of the ribs 121, 122 has an injection port 16 (see FIG. 3) at its bottom surface for injecting a filler. By having the injection port 16 at its bottom surface, the ribs 121, 122 can inject the filler 13 from the bottom surface, allowing the filler 13 to be distributed throughout the entire hollow portion 12a of the rib, and also making it difficult for the filler to seep into the gaps in the connecting portions 12b during injection. In addition, the bottom surface portion is preferably the surface that forms the bottom surface of the rib in the case of a triangle or a rectangle as shown in Figure 1, but in the case of structures other than a triangle or a rectangle, such as a circle, the bottom surface portion is the part that can be seen from the bottom side. Furthermore, one injection port 16 may be provided in each rib, or two or more injection ports 16 may be provided.

[0020] From the viewpoint of enhancing fire resistance, the filler 13 is preferably a fire-resistant material. The fire-resistant material means a material that exhibits performance equivalent to a fire-retardant material (hereinafter referred to as "fire-retardant material") as defined in the Building Standards Act and the Enforcement Order of the Building Standards Act, but is preferably a material that exhibits performance equivalent to a quasi-noncombustible material (hereinafter referred to as "quasi-noncombustible material"), and more preferably a material that exhibits performance equivalent to a noncombustible material (hereinafter referred to as "noncombustible material"). Performance equivalent to a fire-retardant material means a material that exhibits a radiant heat intensity of 50 kW / m in a heat generation test using a cone calorimeter tester in accordance with ISO5660-1.2 When heated at 5 minutes, the total heat generated is 8MJ / m 2 In addition, performance equivalent to semi-non-combustible materials means that the total heat generated after 10 minutes is 8MJ / m 2 In addition, performance equivalent to non-combustible materials means that the total heat generated after 20 minutes is 8MJ / m 2 It means the following:

[0021] The organic foam such as urethane foam used as filler 13 may have performance equivalent to at least one of a flame-retardant material, a semi-non-combustible material, and a non-combustible material, and preferably has performance equivalent to a non-combustible material. When measuring the organic foam in accordance with the ISO-5660 test method, a test sample is prepared by cutting the organic foam into a length of 10 cm, a width of 10 cm, and a thickness of 5 cm, and a heat generation test is performed using the test sample with a cone calorimeter tester.

[0022] The density of the filler 13 is not particularly limited, but is preferably 10 kg / m 3 More than 200kg / m 3 It is preferable that the saturation is 20 kg / m or less. 3 More than 175kg / m 3 More preferably, it is 30 kg / m or less. 3 More than 150kg / m 3 It is more preferable that the density of the filler 13 is equal to or less than the upper limit. By setting the density of the filler 13 equal to or less than the upper limit, the filler 13 becomes lightweight, and the load on the building structure can be reduced. Furthermore, by setting the density of the filler 13 equal to or more than the lower limit, the desired flame retardancy and non-combustibility can be easily achieved. The density of the filler 13 refers to the core density of the filler 13, excluding the skin layer which is the interface between the filler 13 and the inner surface of the rib 12.

[0023] <Flat deck manufacturing method> The method for manufacturing a flat deck according to this embodiment will be described below. The method for manufacturing a flat deck according to this embodiment is a method for manufacturing a flat deck that includes a flat portion 11, a rib 12 protruding from one surface 11D of the flat portion 11, and a filler 13, wherein the rib 12 has a hollow portion 12a having an internal cavity and a connecting portion 12b that connects the hollow portion 12a to the one surface 11D. The method for manufacturing a flat deck according to this embodiment includes a step of eliminating at least some of the gaps in the connecting portion 12b and filling the inside of the rib 12 with the filler 13. According to the above manufacturing method, the filler 13 can be filled into the hollow portion 12a so as not to fill at least a part of the connecting portion 12b. Hereinafter, the flat deck manufacturing method according to this embodiment will be described in more detail as first and second manufacturing methods.

[0024] A first manufacturing method for the flat deck according to this embodiment will be described with reference to FIG. In the first manufacturing method, first, a material is bent to form a rib 12 (cavity portion 12a, connecting portion 12b) protruding from one surface 11D of the flat portion 11 and having an internal cavity (see FIG. 3(a)). Next, the connecting portion 12b of the rib 12, which forms the unfilled portion 15, is compressed from both sides to eliminate any gaps (see FIG. 3(b)). Next, with the connecting portion 12b compressed from both sides to eliminate any gaps, a material for the filler 13 is introduced through an injection port 16 formed in the bottom portion of the hollow portion 12a of the rib 12, and the hollow portion 12a is filled with the filler 13. After the hollow portion 12a of the flat deck 1 formed through the above steps is filled with the filler 13, the pressure on the connecting portion 12b from both sides is released, and the unfilled portion 15 is formed, in which the filler 13 is not filled in the connecting portion 12b and the connecting portion 12b can fit with the claw portion 14 (see FIG. 3(c)).

[0025] A second manufacturing method for the flat deck according to this embodiment will be described with reference to FIG. In the second manufacturing method, first, a material is bent to form a rib 12 (cavity portion 12a, connecting portion 12b) protruding from one surface 11D of the flat portion 11 and having a cavity therein. Next, a spacer 17 is placed in the connecting portion 12b of the rib 12, which forms the unfilled portion 15, to eliminate gaps in the connecting portion 12b (see FIG. 4(a)). Next, with the spacer 17 eliminating gaps in the connecting portion 12b, a material for the filler 13 is injected through an injection port 16 formed in the bottom portion of the hollow portion 12a of the rib 12, filling the hollow portion 12a with the filler 13. After filling the hollow portion 12a with the filler 13, the flat deck 1 formed through the above steps has the spacer 17 removed, leaving the connecting portion 12b unfilled with the filler 13, forming an unfilled portion 15 in which the connecting portion 12b can fit with the claw portion 14 (see FIG. 4(b)). Furthermore, according to the second manufacturing method, by adjusting the position where the spacer 17 is arranged, part of the connecting portion 12b of the rib 12 can be made into the unfilled portion 15.

[0026] <Urethane foam> The urethane foam that constitutes the filler 13 will be described in more detail. The urethane foam used in this embodiment is formed by curing and foaming a urethane resin composition. The urethane resin contained in the urethane foam is a reaction product obtained by mixing and reacting a polyisocyanate compound and a polyol compound. The urethane resin composition is in a liquid state immediately after being prepared by mixing the various components so that it can be easily injected into the interior of the rib 12 and fill the hollow portion 12a of the rib 12 without any gaps. A suitable application method for the urethane foam that fills and closes the hollow portion 12a of the rib 12 is discharge filling using a discharge device that discharges a liquid urethane resin composition. For example, if the urethane resin composition is a two-component curing type, the discharge device used should be one that has a mixing section that mixes the first and second components and a discharge port that discharges the resulting mixed urethane resin composition. Examples of such discharge devices that can be used include high-pressure foaming machines, low-pressure foaming machines, other mixing and dispensing systems, spray guns, and caulking guns.

[0027] The urethane resin composition that forms the urethane foam generally contains a polyisocyanate compound and a polyol compound. Examples of polyisocyanate compounds used in urethane foams include aromatic polyisocyanates, alicyclic polyisocyanates, and aliphatic polyisocyanates. Examples of aromatic polyisocyanates include phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, dimethyldiphenylmethane diisocyanate, triphenylmethane triisocyanate, naphthalene diisocyanate, and polymethylene polyphenyl polyisocyanate.

[0028] Examples of alicyclic polyisocyanates include cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and dimethyldicyclohexylmethane diisocyanate. Examples of the aliphatic polyisocyanate include methylene diisocyanate, ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, and hexamethylene diisocyanate. The polyisocyanate compounds may be used singly or in combination of two or more. The polyisocyanate compound is preferably diphenylmethane diisocyanate (MDI) because it is easy to use and readily available.

[0029] Examples of the polyol compound include polylactone polyol, polycarbonate polyol, aromatic polyol, alicyclic polyol, aliphatic polyol, polyester polyol, polymer polyol, and polyether polyol. Examples of polylactone polyols include polypropiolactone glycol, polycaprolactone glycol, and polyvalerolactone glycol. Examples of polycarbonate polyols include polyols obtained by dealcoholization reaction of a hydroxyl group-containing compound such as ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, octanediol, or nonanediol with diethylene carbonate or dipropylene carbonate.

[0030] Examples of aromatic polyols include bisphenol A, bisphenol F, phenol novolac, and cresol novolac. Examples of alicyclic polyols include cyclohexanediol, methylcyclohexanediol, isophoronediol, dicyclohexylmethanediol, and dimethyldicyclohexylmethanediol. Examples of the aliphatic polyol include ethylene glycol, propylene glycol, butanediol, pentanediol, and hexanediol.

[0031] Examples of polyester polyols include polymers obtained by dehydration condensation of polybasic acids and polyhydric alcohols, polymers obtained by ring-opening polymerization of lactones such as ε-caprolactone and α-methyl-ε-caprolactone, and condensates of hydroxycarboxylic acids and the above-mentioned polyhydric alcohols. Specific examples of polybasic acids include adipic acid, azelaic acid, sebacic acid, terephthalic acid, isophthalic acid, and succinic acid. Specific examples of polyhydric alcohols include bisphenol A, ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, diethylene glycol, 1,6-hexane glycol, and neopentyl glycol. Specific examples of hydroxycarboxylic acids include castor oil and reaction products of castor oil and ethylene glycol.

[0032] Examples of polymer polyols include polymers obtained by graft polymerizing the above-mentioned aromatic polyols, alicyclic polyols, aliphatic polyols, polyester polyols, etc. with ethylenically unsaturated compounds such as acrylonitrile, styrene, methyl acrylate, and methacrylate; polybutadiene polyols; modified polyols of polyhydric alcohols; and hydrogenated products thereof. Examples of modified polyols of polyhydric alcohols include those obtained by modifying raw material polyhydric alcohols by reacting them with alkylene oxides. Examples of polyhydric alcohols used in the modified polyol include trihydric alcohols such as glycerin and trimethylolpropane; tetrahydric to octahydric alcohols such as pentaerythritol, sorbitol, mannitol, sorbitan, diglycerin, and dipentaerythritol; sucrose, glucose, mannose, fructose, methyl glucoside, and derivatives thereof; phenol, phloroglucin, cresol, pyrogallol, catechol, hydroquinone, bisphenol A, bisphenol F, bisphenol S, phenol polybutadiene polyols such as 1-hydroxynaphthalene, 1,3,6,8-tetrahydroxynaphthalene, anthrol, 1,4,5,8-tetrahydroxyanthracene, and 1-hydroxypyrene; castor oil polyols; polymers or copolymers of hydroxyalkyl (meth)acrylates; and polyfunctional polyols (e.g., having 2 to 100 functional groups) such as polyvinyl alcohol; and condensates of phenol and formaldehyde (novolak).

[0033] The method for modifying the polyhydric alcohol is not particularly limited, but a method of adding alkylene oxide (hereinafter abbreviated as AO) is preferably used. Examples of AO include AOs having 2 to 6 carbon atoms, such as ethylene oxide (hereinafter abbreviated as EO), 1,2-propylene oxide (hereinafter abbreviated as PO), 1,3-propylene oxide, 1,2-butylene oxide, and 1,4-butylene oxide. Among these, PO, EO and 1,2-butylene oxide are preferred from the viewpoint of properties and reactivity, and PO and EO are more preferred. When two or more kinds of AO are used (for example, PO and EO), the addition method may be block addition or random addition, or a combination of these.

[0034] Examples of polyether polyols include polymers obtained by ring-opening polymerization of at least one alkylene oxide such as ethylene oxide, propylene oxide, or tetrahydrofuran in the presence of at least one low-molecular-weight active hydrogen compound having two or more active hydrogens. Examples of low-molecular-weight active hydrogen compounds having two or more active hydrogens used in polyether polyols include diols such as bisphenol A, ethylene glycol, propylene glycol, butylene glycol, and 1,6-hexanediol; triols such as glycerin and trimethylolpropane; and amines such as ethylenediamine and butylenediamine.

[0035] The polyol used in the urethane foam is preferably a polyester polyol or a polyether polyol, more preferably a polyester polyol, because of its significant effect of reducing the total heat generated when burned. Among these, it is preferable to use a polyester polyol having a molecular weight of 200 to 800, and more preferably a polyester polyol having a molecular weight of 300 to 500.

[0036] The isocyanate index of the urethane resin is preferably in the range of 120 to 1,000, more preferably in the range of 200 to 800, and even more preferably in the range of 300 to 600. If the isocyanate index is 120 or higher, the isocyanate groups will be in excess of the hydroxyl groups, which will facilitate trimerization and make it easier to impart non-flammability. On the other hand, if the isocyanate index is 1,000 or lower, a good balance between non-flammability and production costs will be achieved.

[0037] The isocyanate index can be calculated by the following method. Isocyanate Index = number of equivalents of polyisocyanate ÷ (number of equivalents of polyol + number of equivalents of water) × 100 Here, each equivalent number can be calculated as follows: Polyisocyanate equivalent number = Amount of polyisocyanate used (g) × NCO content (mass%) / Molecular weight of NCO (mol) × 100 Equivalent weight of polyol = OHV × amount of polyol used (g) ÷ molecular weight of KOH (mmol) OHV is the hydroxyl value of the polyol (mg KOH / g). Equivalents of water = Amount of water used (g) / Molecular weight of water (moles) × Number of OH groups in water In the above formulas, the molecular weight of NCO is 42 (mol), the molecular weight of KOH is 56,100 (mmol), the molecular weight of water is 18 (mol), and the number of OH groups in water is 2.

[0038] Flame retardants To impart flame retardancy to the urethane foam, it is preferable to add a flame retardant, such as a liquid flame retardant such as a phosphate ester, etc. To further improve flame retardancy, it is more preferable to add at least one selected from red phosphorus, phosphate-containing flame retardants, bromine-containing flame retardants, boron-containing flame retardants, antimony-containing flame retardants, and metal hydroxides. The flame retardant used in the urethane foam more preferably contains red phosphorus and a phosphate ester from the viewpoints of non-flammability, ease of handling, etc. Also preferred is a flame retardant consisting of red phosphorus, a phosphate ester, and at least one selected from a phosphate-containing flame retardant, a bromine-containing flame retardant, a boron-containing flame retardant, an antimony-containing flame retardant, and a metal hydroxide.

[0039] <Red phosphorus> There is no limitation on the red phosphorus used in the present invention, and commercially available products can be appropriately selected and used. The red phosphorus does not need to be blended as simple red phosphorus, and may be appropriately surface-treated. The amount of red phosphorus in the urethane foam is preferably in the range of 3.0 to 18 parts by mass, and more preferably 4.0 to 12 parts by mass, per 100 parts by mass of the urethane resin. By adjusting the amount of red phosphorus to be equal to or greater than the above-mentioned lower limit, the self-extinguishing properties of the urethane foam are maintained, and non-flammability is easily imparted to the urethane foam. Furthermore, by adjusting the amount of red phosphorus to be equal to or less than the above-mentioned upper limit, foaming of the urethane resin composition is not inhibited. As described above, the urethane resin is a reaction product of a polyisocyanate compound and a polyol compound, and 100 parts by mass of the urethane resin refers to the total of 100 parts by mass of the polyisocyanate compound and the polyol compound in the urethane resin composition.

[0040] <Phosphate ester> The phosphate ester is not particularly limited, but it is preferable to use a monophosphate ester, a condensed phosphate ester, etc. A monophosphate ester is a compound having one phosphorus atom in the molecule. The monophosphate ester is not particularly limited, and examples thereof include trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri(2-ethylhexyl) phosphate, tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tris(isopropylphenyl) phosphate, tris(phenylphenyl) phosphate, trinaphthyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, diphenyl phosphate, Examples of the acryloyloxyethyl phosphate include diphenyl(2-ethylhexyl)phosphate, di(isopropylphenyl)phenyl phosphate, monoisodecyl phosphate, 2-acryloyloxyethyl acid phosphate, 2-methacryloyloxyethyl acid phosphate, diphenyl-2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, melamine phosphate, dimelamine phosphate, melamine pyrophosphate, and tris(β-chloropropyl)phosphate.

[0041] The condensed phosphate ester is not particularly limited, but examples thereof include condensed phosphate esters such as trialkyl polyphosphate, resorcinol polyphenyl phosphate, resorcinol poly(di-2,6-xylyl) phosphate (manufactured by Daihachi Chemical Industry Co., Ltd., product name PX-200), hydroquinone poly(2,6-xylyl) phosphate, and condensates thereof. Examples of commercially available condensed phosphate esters include resorcinol polyphenyl phosphate (trade name CR-733S), bisphenol A polycresyl phosphate (trade name CR-741), aromatic condensed phosphate ester (trade name CR747), resorcinol polyphenyl phosphate (manufactured by ADEKA Corporation, trade name Adekastab PFR), and bisphenol A polycresyl phosphate (trade names FP-600 and FP-700).

[0042] Among the above, it is preferable to use monophosphate esters, and it is more preferable to use tris(β-chloropropyl)phosphate, because they are effective in reducing the viscosity of the composition before curing and in reducing the initial heat generation. The phosphate esters may be used alone or in combination of two or more.

[0043] The amount of the phosphate ester blended is preferably in the range of 1.5 to 50 parts by mass, more preferably in the range of 1.5 to 20 parts by mass, even more preferably in the range of 2.0 to 15 parts by mass, and most preferably in the range of 2.0 to 10 parts by mass, per 100 parts by mass of the urethane resin. By adjusting the amount of the phosphate ester to the above lower limit or more, cracking of the dense residue formed from the urethane foam in the event of a fire can be prevented. Furthermore, by adjusting the amount of the phosphate ester to the above upper limit or less, foaming of the urethane resin composition is not inhibited. Furthermore, by adjusting the amount within the above range, non-flammability can be easily imparted.

[0044] <Phosphate-containing flame retardants> Examples of phosphate-containing flame retardants include phosphates formed from salts of various phosphoric acids and at least one metal or compound selected from metals of Groups IA to IVB of the periodic table, ammonia, aliphatic amines, and aromatic amines. The phosphoric acid is not particularly limited, and examples thereof include various phosphoric acids such as monophosphoric acid, pyrophosphoric acid, and polyphosphoric acid. Examples of metals in Groups IA to IVB of the periodic table include lithium, sodium, calcium, barium, iron (II), iron (III), and aluminum. Examples of aliphatic amines include methylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, and piperazine. Examples of aromatic amines include pyridine, triazine, melamine, and ammonium. The phosphate-containing flame retardant may be subjected to a known treatment for improving water resistance, such as treatment with a silane coupling agent or coating with a melamine resin.

[0045] Specific examples of phosphate-containing flame retardants include monophosphates, pyrophosphates, and polyphosphates. The monophosphate salt is not particularly limited, and examples thereof include ammonium salts such as ammonium phosphate, ammonium dihydrogen phosphate, and diammonium hydrogen phosphate; sodium salts such as monosodium phosphate, disodium phosphate, trisodium phosphate, monosodium phosphite, disodium phosphite, and sodium hypophosphite; potassium salts such as monopotassium phosphate, dipotassium phosphate, tripotassium phosphate, monopotassium phosphite, dipotassium phosphite, and potassium hypophosphite; lithium salts such as monolithium phosphate, dilithium phosphate, trilithium phosphate, monolithium phosphite, dilithium phosphite, and lithium hypophosphite; barium salts such as barium dihydrogen phosphate, barium hydrogen phosphate, tribarium phosphate, and barium hypophosphite; magnesium salts such as magnesium monohydrogen phosphate, magnesium hydrogen phosphate, trimagnesium phosphate, and magnesium hypophosphite; calcium salts such as calcium dihydrogen phosphate, calcium hydrogen phosphate, tricalcium phosphate, and calcium hypophosphite; and zinc salts such as zinc phosphate, zinc phosphite, and zinc hypophosphite.

[0046] The polyphosphate is not particularly limited, but examples thereof include ammonium polyphosphate, piperazine polyphosphate, melamine polyphosphate, ammonium amide polyphosphate, and aluminum polyphosphate. Among these, it is preferable to use monophosphates, and more preferable to use ammonium dihydrogen phosphate, because the self-extinguishing properties of the phosphate-containing flame retardant are improved. The phosphate-containing flame retardants may be used singly or in combination of two or more.

[0047] The amount of the phosphate-containing flame retardant is preferably in the range of 1.5 to 50 parts by mass, more preferably 1.5 to 20 parts by mass, even more preferably 2.0 to 15 parts by mass, and most preferably 2.0 to 10 parts by mass, per 100 parts by mass of the urethane resin. When the amount of the phosphate-containing flame retardant is equal to or greater than the lower limit, the self-extinguishing properties of the urethane foam are maintained and fire resistance is easily imparted, whereas when the amount of the phosphate-containing flame retardant is equal to or less than the upper limit, foaming of the urethane resin composition is not inhibited.

[0048] Bromine-containing flame retardants The bromine-containing flame retardant is not particularly limited as long as it is a compound containing bromine in its molecular structure, and examples thereof include aromatic brominated compounds. Specific examples of aromatic brominated compounds include monomeric organic bromine compounds such as hexabromobenzene, pentabromotoluene, hexabromobiphenyl, decabromobiphenyl, hexabromocyclodecane, decabromodiphenyl ether, octabromodiphenyl ether, hexabromodiphenyl ether, bis(pentabromophenoxy)ethane, ethylene-bis(tetrabromophthalimide), and tetrabromobisphenol A. Other examples include brominated polycarbonates such as polycarbonate oligomers produced using brominated bisphenol A as a raw material and copolymers of polycarbonate oligomers and bisphenol A; brominated epoxy compounds such as diepoxy compounds produced by reacting brominated bisphenol A with epichlorohydrin and monoepoxy compounds obtained by reacting brominated phenols with epichlorohydrin; halogenated bromine compound polymers such as poly(brominated benzyl acrylate), brominated polyphenylene ether, brominated bisphenol A, condensates of cyanuric chloride and brominated phenol, brominated (polystyrene), poly(brominated styrene), brominated polystyrenes such as crosslinked brominated polystyrene, and crosslinked or non-crosslinked brominated poly(methylstyrene). From the viewpoint of controlling the amount of heat generated in the early stage of combustion, brominated polystyrene, hexabromobenzene, and the like are preferred, with hexabromobenzene being more preferred. The bromine-containing flame retardants may be used singly or in combination of two or more.

[0049] The amount of the bromine-containing flame retardant used in the present invention is preferably in the range of 1.5 to 50 parts by mass, more preferably 1.5 to 20 parts by mass, even more preferably 2.0 to 15 parts by mass, and most preferably 2.0 to 10 parts by mass, per 100 parts by mass of the urethane resin. When the blending amount of the bromine-containing flame retardant is equal to or greater than the lower limit, the self-extinguishing properties of the urethane foam are maintained and fire resistance is easily imparted, while when the blending amount of the bromine-containing flame retardant is equal to or less than the upper limit, foaming of the urethane resin composition is not inhibited.

[0050] <Boron-containing flame retardants> Examples of boron-containing flame retardants include borax, boron oxide, boric acid, and borate salts. Examples of boron oxide include diboron trioxide, boron trioxide, diboron dioxide, tetraboron trioxide, and tetraboron pentoxide. Examples of borates include borates of alkali metals, alkaline earth metals, elements of Groups 4, 12 and 13 of the periodic table, and ammonium. Specific examples include alkali metal borates such as lithium borate, sodium borate, potassium borate, and cesium borate; alkaline earth metal borates such as magnesium borate, calcium borate, and barium borate; zirconium borate, zinc borate, aluminum borate, and ammonium borate. Preferably, the boron-containing flame retardant is a borate, more preferably zinc borate. The boron-containing flame retardants may be used alone or in combination of two or more.

[0051] The amount of the boron-containing flame retardant is preferably in the range of 1.5 to 50 parts by mass, more preferably 1.5 to 20 parts by mass, even more preferably 2.0 to 15 parts by mass, and most preferably 2.0 to 10 parts by mass, per 100 parts by mass of the urethane resin. When the blending amount of the boron-containing flame retardant is equal to or greater than the lower limit, the self-extinguishing properties of the urethane foam are maintained and fire resistance is easily imparted, whereas when the blending amount of the boron-containing flame retardant is equal to or less than the upper limit, foaming of the urethane resin composition is not inhibited.

[0052] <Antimony-containing flame retardants> Examples of the antimony-containing flame retardant used in the present invention include antimony oxide, antimonates, and pyroantimonates. Examples of antimony oxides include antimony trioxide and antimony pentoxide. Examples of antimonate salts include sodium antimonate and potassium antimonate. Examples of pyroantimonate salts include sodium pyroantimonate and potassium pyroantimonate. Preferably, the antimony-containing flame retardant is antimony oxide. The antimony-containing flame retardants may be used singly or in combination of two or more.

[0053] The amount of antimony-containing flame retardant blended is preferably in the range of 1.5 to 50 parts by mass, more preferably 1.5 to 20 parts by mass, even more preferably 2.0 to 15 parts by mass, and most preferably 2.0 to 10 parts by mass, per 100 parts by mass of urethane resin. By blending the amount of antimony-containing flame retardant at or above the lower limit, the self-extinguishing properties of the urethane foam are maintained, and fire resistance is easily imparted. Furthermore, by blending the amount of antimony-containing flame retardant at or below the upper limit, foaming of the urethane resin composition is not inhibited.

[0054] <Metal hydroxide> Examples of metal hydroxides include magnesium hydroxide, calcium hydroxide, aluminum hydroxide, iron hydroxide, nickel hydroxide, zirconium hydroxide, titanium hydroxide, zinc hydroxide, copper hydroxide, vanadium hydroxide, tin hydroxide, etc. The metal hydroxides may be used alone or in combination of two or more.

[0055] The amount of metal hydroxide blended is preferably in the range of 1.5 to 50 parts by mass, more preferably 1.5 to 20 parts by mass, even more preferably 2.0 to 15 parts by mass, and most preferably 2.0 to 10 parts by mass, per 100 parts by mass of urethane resin. When the amount of metal hydroxide blended is equal to or greater than the lower limit, the self-extinguishing properties of the urethane foam are maintained, and fire resistance is easily imparted. Furthermore, when the amount of metal hydroxide blended is equal to or less than the upper limit, foaming of the urethane resin composition is not inhibited.

[0056] Preferred combinations of the flame retardants include, for example, any of the following (a) to (n), and among these, a combination containing at least red phosphorus and a phosphate ester is preferred. (a) Red phosphorus and phosphate esters (b) Red phosphorus and phosphate-containing flame retardants (c) Red phosphorus and bromine-containing flame retardants (d) Red phosphorus and boron-containing flame retardants (e) Red phosphorus and antimony-containing flame retardants (f) Red phosphorus and metal hydroxides (g) Red phosphorus, phosphate ester and phosphate-containing flame retardants (h) Red phosphorus, phosphate esters and bromine-containing flame retardants (i) Red phosphorus, phosphate esters and boron-containing flame retardants (j) Red phosphorus, phosphate-containing flame retardants and bromine-containing flame retardants (k) Red phosphorus, phosphate-containing flame retardants and boron-containing flame retardants (l) Red phosphorus, bromine-containing flame retardants and boron-containing flame retardants (m) Red phosphorus, phosphate esters, phosphate-containing flame retardants and bromine-containing flame retardants (n) Red phosphorus, phosphate esters, phosphate-containing flame retardants, bromine-containing flame retardants and boron-containing flame retardants

[0057] The total amount of flame retardant blended is preferably in the range of 4.5 to 70 parts by mass, more preferably in the range of 4.5 to 40 parts by mass, even more preferably in the range of 4.5 to 30 parts by mass, and most preferably in the range of 4.5 to 20 parts by mass, per 100 parts by mass of urethane resin. When the amount of the flame retardant is equal to or greater than the lower limit, the urethane foam is more easily rendered non-flammable. Furthermore, cracking of the dense residue formed from the urethane foam during a fire can be prevented. When the amount of the flame retardant is equal to or less than the upper limit, foaming of the urethane resin composition is not inhibited by the flame retardant.

[0058] The urethane foam of the present invention is formed by curing and foaming a urethane resin composition, as described above. The urethane resin composition contains the polyol compound, isocyanate compound, and flame retardant, and generally further contains a catalyst, a blowing agent, and a foam stabilizer.

[0059] "catalyst" The urethane resin composition may contain, as a catalyst, for example, a resinification catalyst, a trimerization catalyst, or both, but preferably contains both. The resinification catalyst is a catalyst that promotes the reaction between a polyol compound and a polyisocyanate.

[0060] Examples of the resinification catalyst include nitrogen atom-containing catalysts such as triethylamine, N-methylmorpholine bis(2-dimethylaminoethyl) ether, N,N,N',N",N"-pentamethyldiethylenetriamine, N,N,N'-trimethylaminoethyl-ethanolamine, bis(2-dimethylaminoethyl) ether, N-methyl,N'-dimethylaminoethylpiperazine, and imidazole compounds in which the secondary amine functional group in the imidazole ring is substituted with a cyanoethyl group. The amount of resinification catalyst to be added is preferably in the range of 0.02 to 5 parts by mass, more preferably in the range of 0.04 to 3 parts by mass, even more preferably in the range of 0.04 to 2 parts by mass, and most preferably in the range of 0.06 to 1 part by mass, per 100 parts by mass of urethane resin. By setting the blending amount of the resinification catalyst to the above lower limit or more, the formation of urethane bonds is promoted and curing properties are improved, while by setting the blending amount of the resinification catalyst to the above upper limit or less, an appropriate foaming rate can be maintained and handling is easy.

[0061] A trimerization catalyst is a catalyst that promotes the trimerization of isocyanate groups contained in polyisocyanate compounds, thereby facilitating the formation of isocyanurate rings. The use of a trimerization catalyst makes it easier to improve non-flammability. Examples of trimerization catalysts that can be used include nitrogen-containing aromatic compounds such as tris(dimethylaminomethyl)phenol, 2,4-bis(dimethylaminomethyl)phenol, and 2,4,6-tris(dialkylaminoalkyl)hexahydro-S-triazine; alkali metal salts of carboxylic acids such as potassium acetate, potassium 2-ethylhexanoate, and potassium octoate; tertiary ammonium salts such as trimethylammonium salt, triethylammonium salt, and triphenylammonium salt; and quaternary ammonium salts such as tetramethylammonium salt, tetraethylammonium, and tetraphenylammonium salt.

[0062] The amount of the trimerization catalyst is preferably in the range of 0.6 to 10 parts by mass, more preferably in the range of 0.6 to 8 parts by mass, even more preferably in the range of 0.6 to 6 parts by mass, and most preferably in the range of 0.6 to 3.0 parts by mass, per 100 parts by mass of the urethane resin. When the amount of the trimerization catalyst is equal to or greater than the lower limit, the trimerization of isocyanate is not inhibited, whereas when the amount of the trimerization catalyst is equal to or less than the upper limit, an appropriate foaming rate can be maintained, making the composition easy to handle.

[0063] <Foaming agent> The blowing agent contained in the urethane resin composition promotes the foaming of the urethane resin. Specific examples of the blowing agent include low-boiling hydrocarbons such as water, propane, butane, pentane, hexane, heptane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, and cycloheptane; chlorinated aliphatic hydrocarbon compounds such as dichloroethane, propyl chloride, isopropyl chloride, butyl chloride, isobutyl chloride, pentyl chloride, and isopentyl chloride; fluorine compounds such as trichloromonofluoromethane and trichlorotrifluoroethane; hydrofluorocarbons such as CHF3, CH2F2, and CH3F; dichloromonofluoroethane (for example, HCFC141b (1,1-dichloro-1-fluoroethane), HCFC22 (chlorodifluoromethane), and HCFC142b (1-chloro-1,1-difluoroethane). Examples of suitable physical blowing agents include hydrochlorofluorocarbon compounds such as HFC-245fa (1,1,1,3,3-pentafluoropropane), HFC-365mfc (1,1,1,3,3-pentafluorobutane), HFO-1233zd(E) (trans-1-chloro-3,3,3-trifluoropropene), HFO-1234yf (2,3,3,3-tetrafluoro-1-propene), HFO-1336mzz(Z) (cis-1,1,1,4,4,4-hexafluorobut-2-ene), HFO-1224yd(Z), and other hydroolefin compounds; ether compounds such as diisopropyl ether; and organic physical blowing agents such as mixtures of these compounds; and inorganic physical blowing agents such as nitrogen gas, oxygen gas, argon gas, and carbon dioxide gas.

[0064] The amount of the foaming agent used in the urethane resin composition is preferably in the range of 0.1 to 30 parts by mass per 100 parts by mass of the urethane resin, more preferably in the range of 0.1 to 18 parts by mass, even more preferably in the range of 0.5 to 18 parts by mass, and most preferably in the range of 1 to 10 parts by mass, per 100 parts by mass of the urethane resin. When the content of the blowing agent is equal to or greater than the lower limit, foaming is promoted and the density of the resulting urethane foam can be reduced, whereas when the content of the blowing agent is equal to or less than the upper limit, the foam can be prevented from breaking and the foam can be prevented from not being formed.

[0065] <Foam stabilizer> The foam stabilizer contained in the urethane resin composition improves the foaming properties of the urethane resin composition. Examples of the foam stabilizer include surfactants such as polyoxyalkylene-based foam stabilizers, such as polyoxyalkylene alkyl ethers, and silicone-based foam stabilizers, such as organopolysiloxanes. The amount of foam stabilizer to be added to the urethane resin is preferably within the range of, for example, 0.1 to 10 parts by mass per 100 parts by mass of the urethane resin. The resinification catalyst, trimerization catalyst, blowing agent and foam stabilizer may each be used alone or in combination of two or more thereof.

[0066] The urethane resin composition may further contain an inorganic filler. The inorganic filler is not particularly limited, but examples thereof include silica, diatomaceous earth, alumina, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, ferrites, basic magnesium carbonate, calcium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, dawsonite, hydrotalcite, calcium sulfate, barium sulfate, gypsum fiber, potassium salts of calcium silicate and the like, talc, clay, mica, montmorillonite, bentonite, activated clay, seviolite, imogolite, sericite, glass fiber, glass beads, silica balloon, aluminum nitride, boron nitride, silicon nitride, carbon black, graphite, carbon fiber, carbon balloon, charcoal powder, various metal powders, potassium titanate, magnesium sulfate, lead zirconate titanate, aluminum borate, molybdenum sulfide, silicon carbide, stainless steel fiber, various magnetic powders, slag fiber, fly ash, silica-alumina fiber, alumina fiber, silica fiber, and zirconia fiber. The inorganic fillers may be used alone or in combination of two or more.

[0067] Furthermore, the urethane resin composition may contain additives such as phenolic, amine, or sulfur-based antioxidants, heat stabilizers, metal inhibitors, antistatic agents, stabilizers, crosslinking agents, lubricants, softeners, pigments, and tackifying resins, as well as tackifiers such as polybutene and petroleum resins, as needed, within the scope of the present invention.

[0068] Furthermore, the urethane resin composition may contain additives such as phenolic, amine, or sulfur-based antioxidants, anti-settling agents, heat stabilizers, metal damage inhibitors, antistatic agents, stabilizers, crosslinking agents, lubricants, softeners, and tackifying resins, as needed, provided that the object of the present invention is not impaired.

[0069] Since the urethane resin composition cures through a reaction, it is preferable to separate it into two liquids before molding it into a urethane foam. Specifically, it is preferable to separate it into a polyol liquid containing a polyol compound and an isocyanate liquid containing a polyisocyanate compound. In this case, components other than the polyol compound and the polyisocyanate compound may be blended into the polyol liquid or the isocyanate liquid as appropriate, but are preferably blended into the polyol liquid. This is because polyol compounds have low reactivity and are less likely to cause side reactions even when mixed with components other than the polyol compound and the polyisocyanate compound.

[0070] The urethane resin composition can be made into urethane foam by injecting it into the hollow portion 12a of the rib 12 and allowing it to harden and foam in the hollow portion 12a. The method for injecting the urethane resin composition into the hollow portion 12a of the rib 12 is not particularly limited, but a polyol liquid agent and an isocyanate liquid agent may be mixed to obtain a mixture before being injected into the hollow portion 12a of the rib 12, and the mixture may be injected into the hollow portion 12a of the rib 12, or the polyol liquid agent and the isocyanate liquid agent may be injected separately into the hollow portion 12a of the rib 12 and mixed in the hollow portion 12a. Specifically, although not particularly limited, it is advisable to place an isocyanate liquid and a polyol liquid separately in two containers, mix them using a caulking gun or the like, and then eject the mixture from the caulking gun and inject it into the inside of the rib. When the components of the urethane resin composition are mixed, a reaction begins, and the viscosity increases over time, curing and foaming progress, and the composition loses fluidity to become a polyurethane foam. The urethane resin composition is usually cured and foamed by leaving it at around room temperature (for example, about 10 to 40°C), but may be heated, if necessary.

[0071] <Fire compartment structure> The fire compartment structure according to this embodiment will be described below. As shown in FIG. 5, the fire compartment structure according to this embodiment includes the flat deck 1 and a noncombustible material 20 filling the gaps between the ribs 30 on one surface 11D of the flat portion 11 of the flat deck 1. The flat deck 1 is arranged so that the one surface 11D of the flat portion 11 faces a partition material 31, such as gypsum board. Specifically, for example, the partition material 31 is arranged so that the upper end surface of the partition material 31 faces the bottom surface of the rib 12. In this state, the flat deck 1 and the partition material 31 can be attached with screws or the like. The gaps between the ribs 30, which are the gaps between the flat deck 1 and the partition material 31, are then filled with the noncombustible material 20, resulting in a fire compartment structure as shown in FIG. 5. By filling the gaps between the ribs 30 with the noncombustible material 20, fire resistance can be ensured. Furthermore, even on the outside of the rib 12, a non-combustible material (not shown) may be provided between the partition material 31 and the lower surface 11D of the flat deck 1 as needed. As the non-combustible material 20, a known non-combustible material capable of filling gaps, such as rock wool or glass wool, can be used.

[0072] In the fire compartment structure according to this embodiment, the flat deck 1 is laid across supporting materials such as beams of a building structure to form a floor structure, a roof structure, etc. The flat deck 1 is used, for example, as a formwork material, and when used as a formwork material, concrete (not shown) is poured onto the upper surface 11U.

[0073] As described above, in this embodiment, by filling the hollow portions 12a of the ribs 12 with the filler 13, the cavities formed inside the ribs 12 prevent gaps from forming in the compartments, and it is possible to form compartments with good fire resistance, sound insulation, heat insulation, etc. Also, as described above, by making the filler 13 non-combustible, the fire resistance is further improved. Furthermore, by filling the gaps 30 between the ribs with the non-combustible material 20, the fire resistance can be further improved. In addition, in this embodiment, by inserting and fitting the claw portion 14 of another flat deck 1 arranged adjacently into the unfilled portion 15 provided inside the rib 12 of the flat deck 1, it is possible to connect flat decks 1 arranged adjacent to each other, thereby improving workability.

[0074] (Other embodiments) Although the above description has been given with reference to an example in which the filler 13 is a foam, filler materials other than foam may also be used, such as cement, mortar, and putty. When using a material other than foam, the flat deck may be manufactured by eliminating the gaps in the connecting portions 12b as shown in the manufacturing method above, or the flat deck may be manufactured by filling the filler 13 without eliminating the gaps in the connecting portions 12b. When using a material other than foam, the filler does not foam after being filled inside, so even if the gaps in the connecting portions 12b are not eliminated, the filler can be filled into the hollow portions 12a without the filler 13 penetrating into the gaps in the connecting portions 12b.

[0075] Furthermore, the rib 12 does not necessarily need to be provided with an injection port 16. When the rib 12 does not have an injection port 16, the filler 13 may be filled into the inside of the rib 12 from somewhere other than the injection port. For example, as shown in Fig. 3(a), the top of the rib 12 may be opened to a certain size, and the filler may be filled into the inside of the rib 12 from above the rib 12. Furthermore, the injection port 16 of the rib 12 may be provided somewhere other than the bottom surface. [Explanation of symbols]

[0076] 1 Flat Deck 11 Flat section 11D Bottom surface (one side) 11U top 12 Ribs 12a Cavity 12b Connection part 13 Filling 14 Claw 15 Unfilled area 16 Inlet 17 Spacer 20 Non-combustible materials 30 between ribs 31 Partition material

Claims

1. The device comprises a flat portion, a rib protruding from one surface of the flat portion, and a filler provided inside the rib, the rib has a hollow portion having a cavity therein and a connecting portion connecting the hollow portion and the one surface, A flat deck, wherein the filler is filled inside the cavity portion so as not to fill at least a portion of the connecting portion.

2. The flat deck according to claim 1, wherein the connecting portion is capable of fitting with a claw portion of an adjacent flat deck.

3. 3. The flat deck of claim 1, wherein the filling is foam.

4. The flat deck according to any one of claims 1 to 3, wherein the filler is an organic foam.

5. The flat deck of claim 4 , wherein the organic foam is urethane foam.

6. The density of the packing is 10 kg / m ３ More than 200kg / m ３ The flat deck according to any one of claims 1 to 5, wherein:

7. The filler has a radiant heat intensity of 50 kW / m in a heat generation test using a cone calorimeter tester in accordance with ISO 5660-1. ２ The total heat generation amount for 20 minutes after the start of heating is 8MJ / m ２ The flat deck according to any one of claims 1 to 6, wherein:

8. The flat deck according to any one of claims 1 to 7, wherein the rib has an injection port in a bottom portion thereof for injecting the filler.

9. A flat deck according to any one of claims 1 to 8; and a non-combustible material filling the spaces between the ribs on one surface of the flat portion of the flat deck.

10. A method for manufacturing a flat deck comprising: a flat portion; a rib protruding from one surface of the flat portion; and a filler, wherein the rib has a hollow portion having a cavity therein and a connecting portion connecting the hollow portion and the one surface, A method for manufacturing a flat deck, comprising a step of eliminating at least a portion of the gap at the connecting portion and filling the filler inside the rib.

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