Molded covering material and fire-resistant covering method

Abstract

To provide a molded covering material with excellent workability and reduced thickness variation, and a fire-resistant covering method using the molded covering material.SOLUTION: A molded covering material 50 is formed from a fire-resistant material containing a resin and a thermally expandable component, and is bent at least in part.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a molded coating material used for building structural materials and the like, and a fireproof coating method for coating a coated object with the molded coating material.

Background Art

[0002] Structural materials of buildings, which are important elements in terms of structure, may be coated with fireproof materials to protect them from fire. The structural materials of buildings are generally formed of steel materials. Further, the fireproof material can expand during a fire to form a heat insulation layer, thereby protecting the structural materials of the building from flames and heat during a fire. Conventionally, as the fireproof material, a fireproof sheet obtained by previously molding a fireproof resin composition containing thermally expandable graphite into a sheet shape is known.

[0003] In addition, fireproof paints are also known as fireproof materials. As the fireproof paint, for example, as disclosed in Patent Document 1, those containing a foaming agent, a carbonizing agent, an inorganic powder, and a binder are known. The fireproof paint is generally applied and constructed on structural materials and the like after being diluted with an organic solvent.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, the fireproof sheet is, for example, wound and attached to the structural material. However, if the structural material has corners or becomes complicated, the workability when attaching it to the structural material may decrease.

[0006] On the one hand, the refractory paint can be applied relatively easily even when the shape of the structural material is complex. However, dripping may occur when applying it to the structural material or the like, and the drying time and curing time after application take more than a certain period of time, so the workability is not good. Furthermore, in order for the refractory material to exhibit sufficient refractory performance, a certain thickness or more is required. However, if the thickness is to be a certain thickness or more, thickness errors are likely to occur.

[0007] Therefore, an object of the present invention is to provide a formed coating material with good workability and less likely to cause thickness errors, and a refractory coating method using the formed coating material.

Means for Solving the Problems

[0008] The present invention provides the following [1] to [9]. [1] A formed coating material formed from a refractory material containing a resin and a thermally expandable component, and at least a part of which is bent. [2] The formed coating material according to [1] above, having at least one corner. [3] The formed coating material according to [1] or [2] above, which is in a sheet shape. [4] The formed coating material according to any one of [1] to [3] above, wherein the refractory material further contains a plasticizer. [5] The formed coating material according to [4] above, wherein the refractory material is a plastisol in which the resin is dispersed in a sol state in the plasticizer. [6] The formed coating material according to any one of [1] to [5] above, wherein the resin is at least one selected from the group consisting of polyvinyl chloride resins and acrylic resins. [7] A refractory coating method of coating an object to be coated with the formed coating material according to any one of [1] to [6] above. [8] The refractory coating method according to [7] above, wherein the formed coating material is adhered to the surface of the object to be coated. [9] A method for manufacturing the formed coating material according to any one of [1] to [6] above, A method for manufacturing a formed coating material, comprising coating the outer surface of a forming mandrel with the refractory material and forming a formed coating material with the coated refractory material.

Effects of the Invention

[0009] According to the present invention, it is possible to provide a molded coating material with good workability and less likely to cause thickness errors, and a refractory coating method using the molded coating material.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Embodiments for Carrying Out the Invention

[0011] Hereinafter, the present invention will be described with reference to embodiments. The shaped coating material of the present invention is used by coating a workpiece. The shaped coating material is formed from a refractory material containing a resin and a thermally expandable component and has a shape in which a part thereof is bent. Therefore, the shaped coating material can exhibit fire resistance when heated and the thermally expandable component expands. In addition, since the shaped coating material has a shape in which a part thereof is bent, it can be easily used for a workpiece having a shape in which at least a part of the surface is bent. For example, even if the shape of the workpiece is complicated, the workability is likely to be good. Furthermore, since the shaped coating material can be formed without directly coating the workpiece, the thickness error is less likely to occur.

[0012] The shaped coating material of the present invention is in the form of a flexible sheet and can coat a workpiece after being arranged along the surface of the workpiece. The sheet-shaped shaped coating material is not particularly limited, but its thickness is preferably 0.3 to 10 mm, more preferably 0.8 to 8 mm, and even more preferably 1 to 6 mm. When the thickness of the shaped coating material is 0.3 mm or more, appropriate fire resistance can be imparted by the shaped coating material. In addition, by setting it to 10 mm or less, it is possible to prevent the shaped coating material from becoming thicker than necessary, and it is possible to easily manufacture the shaped coating material by the manufacturing method described later.

[0013] [First Embodiment] Hereinafter, a specific example in the case where the workpiece is an H-shaped steel will be described as the first embodiment with reference to FIGS. 1 and 2. The H-shaped steel as the workpiece has an H shape in a cross section perpendicular to the longitudinal axis direction, and as shown in FIG. 1, it has a plate-shaped web 61 and plate-shaped flanges 62 and 63 connected to both ends of the web 61, respectively. In the H-shaped steel, the web 61 is thinner than the flanges 62 and 63. The thickness of each of the flanges 62 and 63 is not particularly limited, but for example, it is 2 to 40 mm, preferably 3 to 23 mm, and more preferably 5 to 20 mm. The thickness of the web 61 is not particularly limited, but for example, it is 1 to 20 mm, preferably 2 to 16 mm, and more preferably 4 to 12 mm.

[0014] In this specification, the surfaces perpendicular to the thickness direction of the web 61, which is plate-shaped, are defined as surfaces 61A and 61B, the surfaces perpendicular to the thickness direction of the flange 62 are defined as surfaces 62A and 62B respectively, and the surfaces perpendicular to the thickness direction of the flange 63 are described as surfaces 63A and 63B. Further, the end faces at one end of the H-shaped part of the H-shaped steel are described as end faces 62C and 63C respectively, and the end faces at the other end are described as end faces 62D and 63D respectively. Also, in the H-shaped steel which is the object to be constructed 60, each pair of surfaces, or each surface and the end face, are connected via a corner 64.

[0015] In the first embodiment, the cross-section of the H-shaped steel is covered by two formed covering materials 50, 50. As shown in FIG. 1, each of the covering materials 50, 50 has the same shape as each other and covers one surface of the web 61 and half of the flanges 62, 63. That is, each of the covering materials 50, 50 has flat portions 51A to 51G for covering the surface 61A (or 61B) of the web 61, the end faces 63C, 62C (or 63D, 62D) of the flanges 62, 63, and half of each of the surfaces 63A, 63B, 62B, 62A. Also, the connecting portions of the flat portions 51A to 51G are constituted by corners 54 corresponding to the corners 64 of the H-shaped steel. In this embodiment, the corner 54 is preferably a curved surface (a curve in the cross-section) connecting the flat portions. However, the corner 54 may be constituted by connecting straight lines in the cross-section. The formed covering material 54 will have a shape in which a part is bent by the corner 54.

[0016] As shown in Fig. 2, when coating each of the formed coating materials 50, 50 on the object to be coated 60, first, an adhesive may be applied to at least either the outer surface of the object to be coated 60 where the formed coating material is to be coated or the surface of the coating materials 50, 50 on the side of the object to be coated 60. Then, through the adhesive, the outer surface of the object to be coated and the surface of the formed coating material 50 on the side of the object to be coated 60 are adhered, and the outer surface of the object to be coated 60 is coated with the formed coating material 50. As the adhesive, a known adhesive capable of adhering a resin material to the material constituting the object to be coated (in this embodiment, a steel material) may be used, such as an epoxy adhesive, a cyanoacrylate-based adhesive, etc., or a resin used for refractory materials, for example, a polyvinyl chloride-based resin or an acrylic-based resin may also be used. In the case of a polyvinyl chloride-based resin, it may be paste vinyl chloride. Depending on the type of the adhesive, after coating the formed coating material 50 on the object to be coated 60, the adhesive may be cured. For example, if the adhesive is a thermosetting adhesive, heating may be performed. Also, in the case of a hot melt adhesive, etc., the object to be coated 60 may be heated before coating. Further, in the case of paste vinyl chloride, the object to be coated 60 may be heated before coating, and after coating the formed coating material 50 on the object to be coated 60, the adhesive may be secondarily heated.

[0017] In this embodiment, since the formed coating materials 50, 50 are flexible sheets, they can be easily arranged along the surface of the object to be coated 60. Therefore, it is possible to coat the object to be coated 60 with high adhesiveness, and it becomes easier to exhibit fire resistance. Also, each formed coating material 50 has a corner 54, so after aligning the corner 54 with the corner 64 of the object to be coated 60, it may be coated on the object to be coated 60, and thus the workability during construction is further improved.

[0018] Note that each of the formed coating materials 50, 50 may be made slightly larger than the coating target portion of the corresponding object to be coated 60. Therefore, for example, in the cross section, the length of each flat portion 51A to 51G may be made slightly (for example, 2 mm or less, preferably 0.1 to 1 mm) larger than the length of the corresponding portion of each coating target portion of the corresponding object to be coated 60, but if it is made too large as a whole and the gap becomes too large, it may be appropriately made smaller. In this embodiment, specifically, the length of the surface on the object 60 side of the flat portion 51A for covering the surfaces 61A and 61B of the web 61 in the cross section may be slightly larger than the length of the surface 61A (or 61B) of the web 61. Also, in the cross section, the length of the surface on the object 60 side of each of the flat portions 51B and 51C may also be slightly larger than the length of the corresponding end surfaces 63C and 62C (or 63D, 62D) of the flange. Further, in the cross section, the length of the surface on the object 60 side of each of the flat portions 51D and 51G may be slightly larger than half of the length of the surfaces 63A and 62A of the flanges 63 and 62. In the cross section, the length of the surface on the object 60 side of the flat portions 51E and 51F may also be slightly larger than each flat portion in half of the surfaces 63B and 62B of the flanges 62 and 63. Although the size of the formed coating material 50 may deviate from the design value due to errors during forming, by making the size of the coating material 50 slightly larger than the portion to be coated, even if it deviates from the design value, the object 60 can be appropriately coated.

[0019] <Method for manufacturing formed coating material> In the present invention, the formed coating material is formed by coating a refractory material on the outer surface of a forming core mold and using the coated refractory material. Hereinafter, the refractory material used in this embodiment will be described in detail. The refractory material according to this embodiment is a resin composition containing a resin, a plasticizer, and a thermally expandable component.

[0020] <Resin> The resin used for the refractory material in this embodiment includes a thermoplastic resin. By including a thermoplastic resin as the resin, the refractory material gently softens when heated, and voids are formed during softening. The plasticizer described later enters the void portions, and thereby the fluidity is gradually lost and it changes to a gel state. Therefore, the refractory material according to the first embodiment can be formed into a coating film having a certain film thickness, for example, by being applied to a heated forming core mold by dip coating or the like. Therefore, the formed coating material can be easily formed by the refractory material.

[0021] The refractory material according to this embodiment is a plastisol in which a resin such as a thermoplastic resin exists as particles and is dispersed in a sol state in a plasticizer. Since the refractory material is a plastisol, it can be easily applied to a molding die (molding core). Further, in the refractory material, since the thermoplastic resin exists as particles in a sol state, when softened by heating, the plasticizer easily enters the voids, and the workability is easily improved. Furthermore, after the particulate thermoplastic resin is gelled, by further advancing the molten state by heating (secondary heating described later), the particle shape disappears and it integrates with the plasticizer. Therefore, upon cooling after heating, the refractory material becomes a solid-state (also referred to as "quasi-cured") coating film, and the mechanical strength and the like of the coating film are excellent. Note that after coating the molding core, the refractory material needs to be heated for a certain period of time to be quasi-cured. However, since the heating time can be shortened even for a thick coating film, the workability is good.

[0022] Specific resins used for the refractory material include thermoplastic resins such as polyvinyl chloride-based resins and acrylic resins. These resins can form a sol state in the refractory material, and at the same time, the plasticizer can enter easily by heating and gelation can occur easily, so the workability is further improved. Among these, polyvinyl chloride-based resins are preferred because they can be easily demolded from a molding die such as a molding core.

[0023] The polyvinyl chloride-based resin (PVC) may be a homopolymer obtained by polymerizing vinyl chloride alone, or may be a copolymer of vinyl chloride as a main component and a monomer copolymerizable therewith. By using a copolymer, it becomes possible to adjust the glass transition temperature and lower the heating temperature described later. Examples of monomers copolymerizable with vinyl chloride include olefin compounds such as ethylene and propylene, vinyl esters such as vinyl acetate and vinyl propionate, unsaturated monocarboxylic acids such as acrylic acid and methacrylic acid, unsaturated monocarboxylic acid esters such as methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-hydroxyethyl acrylate, methyl methacrylate, ethyl methacrylate, N,N-dimethylaminoethyl methacrylate, unsaturated amides such as acrylamide and methacrylamide, unsaturated nitriles such as acrylonitrile and methacrylonitrile, unsaturated dicarboxylic acids such as maleic acid and fumaric acid, their esters and their anhydrides, N-substituted maleimides, vinyl ethers such as vinyl methyl ether and vinyl ethyl ether, vinylidene compounds such as vinylidene chloride, and the like. The monomers copolymerizable with vinyl chloride may be used alone or in combination of two or more. The polyvinyl chloride-based resin preferably has a constituent unit derived from vinyl chloride of 80% by mass or more, more preferably 90% by mass or more.

[0024] The polyvinyl chloride-based resin is preferably a so-called paste vinyl chloride that is dispersed in a sol state in a plasticizer. Examples of commercially available polyvinyl chloride-based resins used for paste vinyl chloride include the Leuron Paste (registered trademark) series manufactured by Tosoh Corporation, the ZEST (registered trademark) series of Shin Daiichi Vinyl Co., Ltd., and the Kanevynil (registered trademark) paste series manufactured by Kaneka Corporation.

[0025] The acrylic resin is preferably a (meth)acrylic polymer. The (meth)acrylic polymer is a polymer obtained by polymerizing a monomer having a (meth)acryloyl group (also referred to as a “(meth)acrylic monomer”) or a monomer containing acrylonitrile, and may be a homopolymer obtained by polymerizing one of the (meth)acrylic monomers and acrylonitrile alone, or a copolymer obtained by polymerizing two or more of these monomers. The (meth)acrylic polymer is preferably a polymer obtained by polymerizing a monomer containing a (meth)acrylic monomer.

[0026] As the (meth)acrylic monomer, specifically, alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, etc., cyclic alkyl (meth)acrylates such as cyclohexyl (meth)acrylate, carboxyl group-containing monomers such as methacrylic acid, acrylic acid, 2-succinoyloxyethyl-2-methacryloyloxyethyl succinate methacrylate, 2-maleinoyloxyethyl-2-methacryloyloxyethyl maleate methacrylate, 2-phthaloyloxyethyl-2-methacryloyloxyethyl phthalate methacrylate, 2-hexahydrophthaloyloxyethyl-2-methacryloyloxyethyl hexahydrophthalate methacrylate, phosphate group-containing (meth)acrylates such as 2-(meth)acryloyloxyethyl acid phosphate, hydroxyl group-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, carbonyl group-containing (meth)acrylates such as acetoacetoxyethyl (meth)acrylate, amino group-containing (meth)acrylates such as N-dimethylaminoethyl (meth)acrylate, N-diethylaminoethyl (meth)acrylate, acrylamide derivatives such as acrylamidodiacetone acrylamide, N-methylolacrylamide, N-methoxymethylacrylamide, N-ethoxymethylacrylamide, N-butoxymethylacrylamide, etc., polyfunctional (meth)acrylates such as (poly)ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, etc. can be mentioned. Among these, the (meth)acrylic monomer preferably contains at least one of alkyl (meth)acrylate, methacrylic acid, and acrylic acid.

[0027] (Meta)acrylic polymers may be polymers of the above-mentioned (meta)acrylic monomers or polymers of (meta)acrylic monomers and acrylonitrile, or may be polymers of at least one of acrylonitrile and (meta)acrylic monomers and monomers other than acrylonitrile and (meta)acrylic monomers. Examples of monomers other than acrylonitrile and (meta)acrylic monomers include styrene derivatives such as styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, etc., polyfunctional monomers such as divinylbenzene, divinylnaphthalene, divinyl ether, etc., maleic acid derivatives such as itaconic acid, crotonic acid, maleic acid, maleic acid esters, maleic anhydride, etc., fumaric acid derivatives such as fumaric acid, fumaric acid esters, etc., and triaryl isocyanurate.

[0028] (Meta)acrylic polymers preferably have either constituent units derived from (meta)acrylic monomers or constituent units derived from acrylonitrile as the main component, and more preferably have constituent units derived from (meta)acrylic monomers as the main component. Here, the main component means that it is contained in the (meta)acrylic polymer in an amount of 50% by mass or more, preferably 70% by mass or more.

[0029] The acrylic resin is preferably an acrylic sol dispersed in a sol state in a plasticizer. The structure of the particles of the acrylic resin in the acrylic sol is not particularly limited, and examples include a single structure, a core-shell structure of two or more layers, or a gradient structure in which the composition continuously changes from the central part to the outer part of the polymer particles. Among these, a core-shell structure with different compositions for each layer is preferred. By adopting a core-shell structure, the dispersibility in the plasticizer can be enhanced, and the gelling temperature can be appropriately adjusted. Examples of commercially available acrylic resins used in acrylic sols include the Dianaal LP series manufactured by Mitsubishi Chemical Corporation.

[0030] The content of the thermoplastic resin in the refractory material is preferably 10 to 60% by mass, more preferably 20 to 50% by mass, and still more preferably 25 to 45% by mass based on the total amount of the refractory material. If the content of the thermoplastic resin is at least the above lower limit, the refractory material can be appropriately gelled by heating and is also likely to undergo pseudo-curing. On the other hand, if it is at most the above upper limit, it becomes easier to contain a certain amount or more of components other than the resin, such as plasticizers and thermally expandable components, in the refractory material.

[0031] Also, the resin contained in the refractory material may be composed of a thermoplastic resin, but as long as the effects of the present invention are achieved, it may contain resins other than thermoplastic resins. Examples of resins other than thermoplastic resins include thermosetting resins and photocurable resins. In the refractory material, the content of the resin other than the thermoplastic resin may be, for example, 50 parts by mass or less, preferably 30 parts by mass or less, and still more preferably 20 parts by mass or less with respect to 100 parts by mass of the thermoplastic resin. Note that it is preferable that the refractory material does not contain a resin other than the thermoplastic resin, and the content of the resin other than the thermoplastic resin may be 0 parts by mass or more. The resin other than the thermoplastic resin may be contained as a sol in the plasticizer in the refractory material or may be contained in other forms.

[0032] <Plasticizer> As the plasticizer contained in the refractory material, those known in the art can be appropriately selected and used. Specifically, examples include phthalate plasticizers, aliphatic ester plasticizers, trimellitate plasticizers, and phosphate plasticizers. Note that plasticizers are usually liquids at room temperature (23°C).

[0033] Examples of phthalate plasticizers include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, di-2-ethylhexyl phthalate, di-n-octyl phthalate, diisononyl phthalate, diisodecyl phthalate, butyl benzyl phthalate, and the like. Examples of aliphatic ester plasticizers include adipic acid ester plasticizers such as dimethyl adipate, dibutyl adipate, diisobutyl adipate, dihexyl adipate, di-2-ethylhexyl adipate, diisononyl adipate, di-n-octyl adipate, di-n-decyl adipate, diisodecyl adipate, bis[2-(2-butoxyethoxy)ethyl] adipate, bis(2-butoxyethyl) adipate, and the like; and aliphatic ester plasticizers other than adipic acid ester plasticizers such as di-2-ethylhexyl azelate, dibutyl sebacate, di-2-ethylhexyl sebacate, diethyl succinate, methyl acetyl ricinoleate, glyceryl triacetate, and the like.

[0034] Examples of trimellitic acid ester plasticizers include tri-2-ethylhexyl trimellitate, tri-n-octyl trimellitate, tridecyl trimellitate, triisodecyl trimellitate, di-n-octyl-n-decyl trimellitate, and the like. Examples of phosphate plasticizers include trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl phenyl phosphate, and the like.

[0035] Among the above, phthalate plasticizers and aliphatic ester plasticizers are preferred as plasticizers, and among them, phthalate plasticizers and adipic acid ester plasticizers are more preferred. Also, from the viewpoint of reducing environmental impact, plasticizers other than phthalate plasticizers are preferred, and particularly adipic acid ester plasticizers are preferred. The plasticizer may be used alone as one of the above-mentioned ones, or two or more thereof may be used in combination.

[0036] The content of the plasticizer in the refractory material is preferably 40 to 240 parts by mass, more preferably 60 to 180 parts by mass, and still more preferably 70 to 150 parts by mass with respect to 100 parts by mass of the resin contained in the refractory material. When the content of the plasticizer is 40 parts by mass or more, the resin, particularly the thermoplastic resin, is easily dispersed in a sol state in the plasticizer, and is easily gelled and pseudo-cured by heating, making it easier to further improve workability. Also, it becomes easier to impart a certain degree of flexibility to the coating film formed from the refractory material. On the other hand, when the content of the plasticizer is 240 parts by mass or less, it is possible to prevent the viscosity during coating from becoming low, making it easier to form a coating film with a large film thickness. Also, it becomes easier to suppress the occurrence of dripping after coating, and furthermore, it becomes easier to impart a certain degree of mechanical strength to the coating film.

[0037] <Thermal expansion component> As the thermal expansion component contained in the refractory material, thermally expandable layered inorganic substances, foaming agents, etc. can be used. The thermally expandable layered inorganic substance is a conventionally known substance that expands upon heating, and examples thereof include vermiculite, thermally expandable graphite, etc., and thermally expandable graphite is particularly preferable. As the thermally expandable layered inorganic substance, particulate or flaky ones may be used. Since the thermally expandable layered inorganic substance expands upon heating to form a large volume of voids, the formed coating material made of the refractory material can form a heat insulation layer with excellent heat insulation performance during a fire.

[0038] Thermally expandable graphite is obtained by treating powders such as natural flake graphite, pyrolytic graphite, and kish graphite with an inorganic acid and a strong oxidizing agent to form a graphite intercalation compound, and is a kind of crystalline compound that maintains the layered structure of carbon. Examples of the inorganic acid include concentrated sulfuric acid, nitric acid, and selenic acid. Examples of the strong oxidizing agent include concentrated nitric acid, persulfate, perchloric acid, perchlorate, permanganate, dichromate, dichromate, and hydrogen peroxide. The thermally expandable graphite obtained by the acid treatment as described above may be further neutralized with ammonia, aliphatic lower amines, alkali metal compounds, alkaline earth metal compounds, and the like.

[0039] The particle size of the thermally expandable graphite is preferably 20 to 200 mesh. When the particle size of the expandable graphite is within the above range, it is easy to expand and create a large volume of voids, thus improving the fire resistance. Also, the dispersibility in the resin is improved. The average aspect ratio of the thermally expandable graphite is preferably 2 or more, more preferably 5 or more, and even more preferably 10 or more. The upper limit of the average aspect ratio of the thermally expandable graphite is not particularly limited, but from the viewpoint of preventing cracking of the thermally expandable graphite, it is preferably 1,000 or less. When the average aspect ratio of the thermally expandable graphite is 2 or more, it is easy to expand and create a large volume of voids, thus improving the flame retardancy. The average aspect ratio of the thermally expandable graphite is the average value of the values obtained by measuring the maximum dimension (major axis) and the minimum dimension (minor axis) for each of 10 thermally expandable graphites and dividing the maximum dimension (major axis) by the minimum dimension (minor axis). The major axis and minor axis of the thermally expandable graphite can be measured using, for example, a field emission scanning electron microscope (FE-SEM).

[0040] The foaming agent used for the thermally expandable component is a foaming agent that foams upon heating, and is preferably a nitrogen-containing compound-based foaming agent. When the nitrogen-containing compound-based foaming agent is heated, it thermally decomposes, sublimates, or vaporizes at a certain temperature or higher, generating gases such as nitrogen and ammonia. Therefore, a formed coating material formed of a refractory material containing a nitrogen-containing compound-based foaming agent is likely to form a heat-insulating layer with excellent heat-insulating performance during a fire.

[0041] Examples of nitrogen-containing compound-based foaming agents include phosphate-based compounds such as ammonium phosphate, ammonium polyphosphate, melamine phosphate, and melamine polyphosphate; melamine-based compounds such as melamine, methylol melamine, melamine cyanurate, and melamine-formaldehyde resin; azo dicarboxamide, metal azodicarboxylates such as barium azodicarboxylate, azo compounds such as azobisisobutyronitrile, nitroso compounds such as N,N'-dinitrosopentamethylenetetramine, hydrazodicarboxamide, hydrazine derivatives such as 4,4'-oxybis(benzenesulfonyl hydrazide) and toluenesulfonyl hydrazide, and semicarbazide compounds such as toluenesulfonyl semicarbazide. Among these, phosphate-based compounds and melamine-based compounds are preferred from the viewpoint of foaming temperature and the like. By using these foaming agents, it becomes easy to form a heat-insulating layer with good heat-insulating performance in the molded coating material. In addition, the phosphate-based compound acts as a catalyst for promoting the polymerization of the charring agent described later by heating during a fire, and the phosphate-based compound itself can form an inorganic phosphate film, enhancing the fire resistance and heat-insulating performance of the coating film. Among the nitrogen-containing compound-based foaming agents, ammonium polyphosphate and melamine are preferred. The thermally expandable component may be used alone or in combination of two or more.

[0042] The content of the thermally expandable component in the refractory is preferably 10 to 200 parts by mass, more preferably 20 to 140 parts by mass, and still more preferably 30 to 80 parts by mass with respect to 100 parts by mass of the resin contained in the refractory. When the content of the thermally expandable component is 10 parts by mass or more, the molded coating material formed of the refractory can appropriately expand by heating during a fire and form a heat-insulating layer with excellent heat-insulating performance. Also, by setting it to 200 parts by mass or less, the ratio of the resin and plasticizer in the refractory can be kept above a certain level, so that the viscosity of the refractory can be appropriately adjusted, and gelation and pseudo-curing can be appropriately carried out when heated. Furthermore, the mechanical strength of the molded coating material and the like can be easily improved.

[0043] <Charring agent> The refractory material according to this embodiment may contain a charring agent. When the coating film is heated by a fire and the heat-insulating layer is formed by the above-described thermally expandable component, the charring agent can form a charred layer to improve the heat-insulating performance of the heat-insulating layer. The charring agent can be preferably used when a foaming agent, particularly a nitrogen-containing compound-based foaming agent, is used as the above-described thermally expandable component. The charring agent preferably polymerizes upon heating during a fire to form a charred layer.

[0044] When the refractory material contains a charring agent, it preferably further contains an acidic component that reacts with the charring agent upon heating to promote polymerization. The acidic component may be an acidic substance that exhibits acidity at normal temperature, or may be a substance that generates an acidic substance by decomposition or the like upon heating. As the acidic component, phosphates, particularly polyphosphates, are preferable, and in particular, phosphate-based compounds that can also be used as the above-described foaming agent are preferable, and ammonium polyphosphate is more preferable. That is, when the refractory material contains a charring agent, it preferably contains the above-described phosphate-based compound that also functions as a foaming agent. Further, when the refractory material contains a charring agent, from the viewpoint of sufficiently promoting foaming during a fire to form a heat-insulating layer having excellent heat-insulating properties, in addition to phosphates, it preferably further contains a foaming agent other than phosphates, and more preferably further contains a melamine-based compound.

[0045] As the charring agent, polyhydric alcohols are preferable, and among them, polyhydric alcohols having three or more hydroxyl groups are more preferable. By using a polyhydric alcohol as the charring agent, particularly a polyhydric alcohol having three or more hydroxyl groups, a charred layer can be appropriately formed by the charring agent. Specific examples of the polyhydric alcohol used as the charring agent include polyhydric alkanols such as pentaerythritol, dipentaerythritol, pentaerythritol, dipentaerythritol, tripentaerythritol, trimethylolpropane, ditrimethylolpropane, tritrimethylolpropane, or their 2-4 mers, and polysaccharides such as cellulose.

[0046] The content of the carbonizing agent in the refractory material is preferably 2 to 40 parts by mass, more preferably 4 to 25 parts by mass, and still more preferably 6 to 20 parts by mass with respect to 100 parts by mass of the resin contained in the refractory material. When the content of the carbonizing agent is 2 parts by mass or more, it becomes easier to improve the heat insulation property by the carbonized layer formed by the carbonizing agent. Further, when the content is 40 parts by mass or less, it becomes easier to exhibit an effect commensurate with the content.

[0047] When the refractory material contains a carbonizing agent, as described above, it is preferably contained both a phosphate-based compound such as ammonium polyphosphate and a melamine-based compound. When the refractory material contains both a phosphate-based compound and a melamine-based compound, the content of the phosphate-based compound is preferably 5 to 80 parts by mass, more preferably 15 to 65 parts by mass, and still more preferably 25 to 55 parts by mass with respect to 100 parts by mass of the resin contained in the refractory material. Also, the content of the melamine-based compound is preferably 2 to 25 parts by mass, more preferably 4 to 20 parts by mass, and still more preferably 6 to 15 parts by mass with respect to 100 parts by mass of the resin contained in the refractory material. In addition, when both a phosphate-based compound and a melamine-based compound are contained, the mass ratio of the content of the melamine-based compound to the content of the phosphate-based compound (melamine-based compound / phosphate-based compound) is, for example, 1 / 20 to 1, but the content of the phosphate-based compound is preferably more than the content of the melamine-based compound, and the above mass ratio is preferably 1 / 15 to 9 / 10, and more preferably 1 / 8 to 1 / 2.

[0048] <Flame retardant> The refractory material may further contain a flame retardant. Examples of the flame retardant include those other than the above-described thermally expandable components, and specifically include phosphate-containing flame retardants, boron-containing flame retardants, metal hydroxide-based flame retardants, halogen-based flame retardants, and other metal-containing compounds.

[0049] Examples of the phosphate-containing flame retardant include phosphates composed of salts of phosphoric acids and at least one selected from metals of Groups IA to IVB of the periodic table. The phosphoric acids are not particularly limited, and may be monophosphoric acids such as phosphoric acid, phosphorous acid, hypophosphorous acid, etc., or may be pyrophosphoric acid, polyphosphoric acid, etc. Examples of the metals of Groups IA to IVB of the periodic table include lithium, sodium, calcium, barium, iron (II), iron (III), aluminum, etc. In addition, the above-mentioned phosphate-containing flame retardants may be subjected to known water resistance improvement treatments such as treatment with a silane coupling agent and coating with a melamine resin.

[0050] Specific examples of the phosphate-containing flame retardants include, for example, monophosphates, pyrophosphates, polyphosphates, etc. The monophosphates are not particularly limited, and examples include sodium salts such as sodium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, sodium phosphite, disodium phosphite, sodium hypophosphite, etc., potassium salts such as potassium dihydrogen phosphate, dipotassium hydrogen phosphate, tripotassium phosphate, potassium phosphite, dipotassium phosphite, potassium hypophosphite, etc., lithium salts such as lithium dihydrogen phosphate, dilithium hydrogen phosphate, trilithium phosphate, lithium phosphite, dilithium phosphite, lithium hypophosphite, etc., barium salts such as barium dihydrogen phosphate, barium hydrogen phosphate, tribarium phosphate, barium hypophosphite, etc., magnesium salts such as magnesium hydrogen phosphate, magnesium hydrogen phosphate, trimagnesium phosphate, magnesium hypophosphite, etc., calcium salts such as calcium dihydrogen phosphate, calcium hydrogen phosphate, tricalcium phosphate, calcium hypophosphite, etc., zinc salts such as zinc phosphate, zinc phosphite, zinc hypophosphite, etc., and aluminum salts such as aluminum phosphite. The polyphosphates are not particularly limited, and examples include aluminum polyphosphate. As the phosphate-containing flame retardant used in the refractory material, aluminum salts such as aluminum phosphite are preferred.

[0051] Examples of the boron-containing flame retardant include borax, boron oxide, boric acid, borate, etc. Examples of boron oxide include diboron trioxide, boron trioxide, diboron dioxide, tetraboron trioxide, tetraboron pentoxide, etc. Examples of borates include borates of alkali metals, alkaline earth metals, Group 4, Group 12, or Group 13 elements of the periodic table, etc. Specifically, alkali metal borate salts such as lithium borate, sodium borate, potassium borate, cesium borate, etc., alkaline earth metal borate salts such as magnesium borate, calcium borate, barium borate, etc., zirconium borate, zinc borate, aluminum borate, etc. can be mentioned. The boron-containing flame retardant used in the present invention is preferably a borate, and more preferably zinc borate.

[0052] Examples of the metal hydroxide-based flame retardant include metal hydroxides such as magnesium hydroxide, calcium hydroxide, aluminum hydroxide, iron hydroxide, nickel hydroxide, zirconium hydroxide, titanium hydroxide, zinc hydroxide, copper hydroxide, vanadium hydroxide, tin hydroxide, etc. As the metal hydroxide, aluminum hydroxide is preferred.

[0053] Examples of halogen-based flame retardants include chlorine-based flame retardants and bromine-based flame retardants, with bromine-based flame retardants being preferred. The bromine-based flame retardants are not particularly limited as long as they are compounds containing bromine in their 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(pentabromophenyl), ethylene bis(tetrabromophthalimide), tetrabromobisphenol A, etc.; brominated polycarbonates such as polycarbonate oligomers produced from brominated bisphenol A, copolymers of the above polycarbonate oligomer and bisphenol A, etc.; brominated epoxy compounds such as diepoxy compounds produced by reacting brominated bisphenol A and epichlorohydrin, monoepoxy compounds obtained by reacting brominated phenols and epichlorohydrin, etc.; poly(brominated benzyl acrylate), brominated polyphenylene ether, brominated bisphenol A, condensates of cyanuric chloride and brominated phenols, brominated polystyrenes such as brominated (polystyrene), poly(brominated styrene), crosslinked brominated polystyrene, etc.; halogenated bromine compound polymers such as crosslinked or non-crosslinked brominated poly(α-methylstyrene).

[0054] Examples of metal-containing compounds other than the above compounds include metal oxides such as aluminum oxide, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, titanium oxide, etc.; metal carbonates such as calcium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, etc.; metal sulfates such as calcium sulfate, barium sulfate, magnesium sulfate, etc. Among these, metal oxides and metal carbonates are preferred, and titanium oxide and calcium carbonate are more preferred. The flame retardant may be used alone or in combination of two or more of the above-mentioned ones.

[0055] The content of the flame retardant in the refractory material is preferably 5 to 120 parts by mass, more preferably 10 to 100 parts by mass, and even more preferably 20 to 70 parts by mass with respect to 100 parts by mass of the resin contained in the refractory material. When the content of the flame retardant is 5 parts by mass or more, the flame retardancy of the formed coating material formed by the refractory material with the flame retardant can be improved. Further, when it is 120 parts by mass or less, other components such as resin, plasticizer, and thermal expansion component can be contained in the refractory material at a sufficient ratio.

[0056] <Other additives> The refractory material can contain additional components other than the above as necessary within a range not impairing the object of the present invention. The type of this additional component is not particularly limited, and various additives can be used. Examples of such additives include inorganic fillers, lubricants, shrinkage preventers, crystal nucleating agents, colorants (pigments, dyes, etc.), ultraviolet absorbers, antioxidants, anti-aging agents, flame retardant aids, antistatic agents, surfactants, vulcanizing agents, dispersants, and surface treatment agents other than the above-mentioned flame retardants and thermal expansion components. The addition amount of the additive can be appropriately selected without impairing the object of the present invention. These additives may be used alone or in combination of two or more.

[0057] The refractory material according to this embodiment is preferably substantially solvent-free. Note that substantially solvent-free means that the refractory material does not contain an organic solvent and water, or even if it contains them, the amount is trace. Specifically, the total content of water and solvent in the refractory material is preferably 3% by mass or less, preferably 1% by mass or less, more preferably 0.5% by mass or less, and even more preferably 0.1% by mass or less with respect to the total amount of the refractory material. Since the refractory material is substantially solvent-free, it does not need to be dried after coating, so the workability is improved, and it is also easy to reduce the environmental load.

[0058] The refractory material can be obtained by mixing the components that make up the refractory material. For example, it can be obtained by adding and mixing a resin, a thermally expandable component, and further a carbonizing agent, a flame retardant, and other additives that are blended as required to a plasticizer. The refractory material is a plastisol as described above. Therefore, the mixing of the components may be carried out by stirring with a known mixer so that the thermoplastic resin can be dispersed in the plasticizer in a sol state. In addition, components other than the thermoplastic resin, for example, the thermally expandable component, the carbonizing agent, the flame retardant, resins other than the thermoplastic resin, and other additives may be dispersed in the plasticizer or dissolved by the above mixing.

[0059] (Manufacturing method) Next, a manufacturing method of a molded coating material using the above-described refractory material will be described in detail. The manufacturing method of the molded coating material according to the first embodiment of the present invention includes an immersion step of immersing a molding core mold in the refractory material placed inside an immersion tank, and a demolding step of demolding the coating film made of the refractory material formed on the surface by immersion from the molding core mold as the molded coating material.

[0060] As the molding core mold, one having the same surface shape as the object to be coated may be used. In this embodiment, an H-shaped steel may be used. The configuration of the H-shaped steel is as described for the above-described object to be coated. However, in the H-shaped steel used as the molding core mold, the web 61 and the flanges 62 and 63 are described as the web 11 and the flanges 12 and 13, and the surfaces 61A, 61B, 62A, 62B, 63A, 63B, one end surface 62C, 63C, and the other end surface 62D, 63D are described as the surfaces 11A, 11B, 12A, 12B, 13A, 13B, one end surface 12C, 13C, and the other end surface 12D, 13D, respectively.

[0061] In this embodiment, at least a part of the inner surface of the dipping tank used in the dipping process is provided with a predetermined interval with respect to at least a part of the outer surface of the molding core to be dipped, and it is preferably shaped to correspond to the workpiece (i.e., the molding core). Since the shape of the inner surface of the dipping tank corresponds to the shape of the molding core, it is possible to reduce the amount of refractory material filled inside the dipping tank while being a dip coat. When the refractory material filled in the dipping tank comes into contact with the molding core, impurities (for example, those that adhered to the workpiece as pseudo-cured products and remained in the dipping tank without completely adhering to the workpiece) may be mixed in. Further, the refractory material may be heated when the heated workpiece is dipped, but impurities may be generated by heating and cause contamination. As the contamination progresses, for example, the viscosity of the plastisol changes due to impurities such as pseudo-cured products, making it difficult to control the thickness of the coating film. In this embodiment, as described above, by reducing the amount of refractory material filled inside the dipping tank, after dipping the molding core, the amount of refractory material remaining in the dipping tank can be reduced, or the dipping tank can be made to have no refractory material remaining. Therefore, the generation of contaminated refractory material can be suppressed, raw material loss is reduced, and a coating film (molding coating material) of refractory material with good quality can be obtained with high production efficiency.

[0062] In the manufacturing method according to this embodiment, it is preferable to perform a heating process before the dipping process and a secondary heating process after the dipping process. Further, the secondary heating process is preferably performed before the demolding process. Therefore, in this embodiment, the heating process, the dipping process, the secondary heating process, and the demolding process may be performed in this order. Hereinafter, each process will be described in detail.

[0063] (Heating process) The heating process is a process of heating the molding core 10 before dipping. The molding core 10 may be heated to a temperature higher than the temperature of the refractory material 21 during dipping. For example, it may be heated to about 45 to 180°C, preferably 60 to 150°C, more preferably 80 to 140°C. These heating temperatures are the temperatures of the molding core 10 when it is immersed in the refractory material 21. In addition, dipping may be performed two or more times on the same molding core in the third embodiment described later. However, a heating process may be included between each dipping process (for example, the first and second dipping processes described later) so that the above temperature is reached at each dipping. The method of heating the molding core 10 is not particularly limited. The molding core 10 may be put into a heating oven and heated, or may be heated by hot air, an infrared heater, or the like.

[0064] (Dipping process) In this embodiment, the molding core 10 heated as described above is immersed in the refractory material 21 filled inside the dipping tank 20 as shown in FIGS. 3(A) and (B), so that the refractory material 21 is coated on the molding core 10, and the coating films 11X, 12X, and 13X of the refractory material 21 are formed. The coating films 11X, 12X, and 13X are coating films formed on the web 11, the flange 12, and the flange 13, respectively (see FIG. 3(C)). The coating film becomes the molding covering material 50 as described above. In this embodiment, by using dip coating by dipping, a coating film can be formed on the outer surface of the molding core 10 with high workability without dripping or the like.

[0065] In the manufacturing method of this embodiment, the thermal energy of the heated molding core 10 is transferred to the refractory material existing around the molding core 10, and the refractory material 21 is heated. As a result, the refractory material 21 loses fluidity and gels to become the coating films 11X, 12X, and 13X. Therefore, the greater the transferred thermal energy, the greater the thickness of the coating films 11X, 12X, and 13X. Thus, the thickness of the coating films 11X, 12X, and 13X, that is, the thickness of the molding covering material, can be adjusted by adjusting the heating temperature of the molding core 10. In addition, since the heat capacity of the molding core 10 varies depending on its shape, size, etc., the thermal energy transferred to the refractory material 21 can result in different coating film thicknesses depending on the position where the refractory material 21 is coated and the coating method, even if the molding core 10 is heated to the same temperature.

[0066] For example, even when the molding core 10 is heated to the same temperature, the greater the thickness of the molding core 10, the greater its heat capacity, and thus the greater the heat transfer to the coated refractory material 21, enabling the formation of a coating film with a large thickness. Also, when only one side of the plate-shaped molding core 10 (e.g., the web 11) is coated, the thermal energy accumulated in the molding core 10 is concentrated and transferred to the refractory material 21 on one side, allowing the formation of a relatively thick coating film. On the other hand, when both sides (e.g., both sides of the flanges 12, 13) are coated, the thermal energy accumulated in the molding core 10 is dispersed and transferred to the refractory material 21 on both sides, enabling the formation of a relatively thin coating film. In contrast, in the present embodiment, as will be described later, the intervals D1 to D7 are adjusted to a size equal to or less than the thickness of the coating film that can be formed by the above thermal energy. Therefore, the coating films 11X, 12X, 13X formed on the molding core 10 can be prevented from having thickness variations due to the coating position, coating method, temperature change of the molding core 10, etc.

[0067] The temperature of the refractory material 21 before dipping (i.e., the temperature of the refractory material 21 inside the dipping tank 20) may be near room temperature, for example, about 0 to 50°C, preferably 10 to 40°C, and more preferably 20 to 30°C. By coating the refractory material 21 at a temperature near room temperature, it can be easily maintained in a sol state with fluidity before adhering to the molding core 10. Thus, it can be coated on the molding core 10 with high workability, and for example, it is also possible to coat the molding core 10 without gaps and with a uniform thickness.

[0068] Since the molded coating material 50 in this embodiment has a shape that covers a part of the object to be constructed (H-shaped steel) 60 in the cross section, in the dipping process, it is advisable to dip a part of the molding core (H-shaped steel) 10 into the refractory material 21. Specifically, as shown in Fig. 3(B), it is inserted into the refractory material 21 inside the dipping tank 20 from one end face 12C, 13C side of the flange, and the flanges 12, 13 are dipped from the one end faces 12C, 13C over the central part which is the connecting part with the web 11 and coated with the refractory material 21. At this time, both surfaces 12A, 12B, 13A, 13B of the flanges 12, 13 will be coated. Also, one surface 11A of the web 11 will also be dipped and coated.

[0069] On the other hand, the shape inside the dipping tank 30 has a shape that conforms to the shape of the molding core 10 to be dipped (that is, the object to be constructed 60), as shown in Fig. 3(A). Specifically, it is preferably composed of a cavity having recesses 32, 33 that conform to the shape of the flanges 12, 13 and a connecting part 31 that conforms to the shape of the web 11 connecting the upper ends of the recesses 32, 33 between the recesses 32, 33. Also, the dipping tank 20 includes a sheet-like member 25 and a base member 26 that supports the sheet-like member 25. The sheet-like member 25 constitutes the inner surface 20A of the dipping tank 20, and thus, the above-described recesses 32, 33 and the connecting part 31 are formed inside it. The sheet-like member 25 may be composed of a sheet having high mold release property with respect to the refractory material 21 and having flexibility, and for example, it may be composed of a known mold release sheet such as a silicone sheet or a fluororesin sheet. The sheet-like member 25 is used as a mold release sheet for releasing the molding core 10 with a coating film formed thereon from the dipping tank 20 as will be described later.

[0070] The base member 26 is composed of four members, and includes central portions 26A and 26B where the connection portion 31 is provided upward, and both side portions 26C and 26D provided on both sides of the central portions 26A and 26B. The portion corresponding to the recess 32 is formed by the central portion 26A and the side portion 26C, and the portion corresponding to the recess 33 is formed by the central portion 26B and the side portion 26D. A clearance 27 is provided between each of the side portion 26C, the central portion 26A, the central portion 26B, and the side portion 26D, and the central portions 26A and 26B are displaceable in the left - right direction in FIG. 1. Although not shown, a sponge or the like may be appropriately inserted into the clearance 27.

[0071] The internal shape of the dipping tank 20 (that is, the shape of the cavity) may have a shape that is slightly larger than the molding core 10 so that a predetermined interval is formed between the inner surface 20A of the dipping tank 20 and the outer surface of the immersed molding core 10 as shown in FIG. 3(B). That is, as shown in FIG. 3(B), the intervals D1, D2 between the surfaces 12A, 12B of the flange 12, which are the surfaces to be coated, and the side surfaces of the recess 32, the interval D3 between one end surface 12C and the bottom surface of the recess 32, the intervals D4, D5 between the surfaces 13A, 13B of the flange 13 and the side surfaces of the recess 33, the interval D6 between one end surface 13C and the bottom surface of the recess 33, and the interval D7 between the surface 11A of the web 11 and the upper surface of the connection portion 31 are preferably a predetermined interval.

[0072] Here, it is preferable that the intervals D1 to D7 are the same as each other, but they may be different from each other. Also, in this embodiment, the intervals D1 to D7 are sized corresponding to the thicknesses of the coating films 11X, 12X, 13X to be formed (that is, the thickness of the molding covering material 50), and are preferably 0.3 to 10 mm, more preferably 0.8 to 8 mm, and even more preferably 1 to 6 mm. Note that the molding core 10 may be suspended from a support member (not shown) or placed on the inner surface 20A of the dipping tank 20 so that the intervals D1 to D7 are within the above - mentioned range.

[0073] In this embodiment, in the dipping process, the heated molding core 10 is dipped into the refractory material 21, and the thermal energy of the molding core 10 is transferred to the refractory material 21, enabling the formation of a coating film with a certain thickness. However, the above intervals D1 to D7 are sized to be less than or equal to the thickness of the coating film that can be formed by thermal energy. As a result, the coating films 11X, 12X, and 13X are all formed by the inner surface 20A of the dipping tank 20. Therefore, coating films 11X, 12X, and 13X having thicknesses corresponding to the intervals D1 to D7 are formed on the outer surface of the molding core 10. That is, for example, if the interval D7 is 5 mm, the thickness of the coating film 11X formed on the surface 11A of the web 11 is also approximately 5 mm. Thus, in this embodiment, the interior of the dipping tank 20 where the molding core 10 and the refractory material 21 are disposed is sized to be slightly larger than the molding core 10 by the thickness of the coating film to be formed. Therefore, the molding core 10 becomes a male mold, the dipping tank 20 becomes a female mold, and the molding core 10 and the dipping tank 20 constitute a molding die.

[0074] The molding core 10 with the coating films 11X, 12X, and 13X formed on its surface may be pulled out of the dipping tank 20 and removed from the dipping tank 20. At this time, in the support member 26, as shown in FIG. 3(C), the central portions 26A and 26B may be displaced so as to be separated from the outer portions 26C and 26D, respectively. When the central portions 26A and 26B are displaced, the recesses 32 and 33 formed by the sheet-like member 25 are partially unsupported by the support member 26, so that the recesses 32 and 33 formed by the sheet-like member 25 can be easily deformed. Therefore, the molding core 10 with the coating films 11X, 12X, and 13X formed thereon can be easily demolded from the dipping tank 20 that constitutes the female mold by deforming the recesses 32 and 33 and removed from the dipping tank 20.

[0075] In addition, in this embodiment, the refractory material 21 inside the immersion tank 20 only needs to be filled inside the immersion tank 20 up to the height position H (see Fig. 3(B)) where the molding core 10 can coat the outer surfaces of the halves on the end face 12C, 13C sides of the flanges 12, 13, and one surface 11A of the web 11 when the molding core 10 is placed inside the immersion tank 20. Therefore, before the molding core 10 is immersed, the refractory material 21 does not need to be filled up to the height position H, and it may be filled up to a position lower than the height position H as shown in Fig. 3(A). When the molding core 10 is placed inside the immersion tank 20, the refractory material 21 filled in this way is pushed aside by the molding core 10 and reaches the height position H, so that the outer surfaces of the end faces 12C, 13C sides of the flanges 12, 13, and the surface 11A of the web 11 can be coated. Also, it is preferable that substantially all of the refractory material 21 inside the immersion tank 20 is coated on the molding core 10. When removed from the molding core 10, there may be no remaining refractory material 21 inside the immersion tank 20 as shown in Fig. 3(C). When substantially all of the refractory material 21 inside the immersion tank 20 is coated on the molding core 10, it is possible to suppress the generation of the contaminated refractory material 21.

[0076] (Secondary heating process) The secondary heating process is a process of further heating (hereinafter also referred to as "secondary heating") the molding core 10 with a coating film formed on its surface after the above immersion process. The secondary heating process is preferably performed after the molding core 10 with a coating film formed on its surface is removed from the immersion tank 20. By being secondary heated, the refractory material 21 on the molding core 10 causes the thermoplastic resin to further melt, the particle shape to disappear, and it integrates with the plasticizer. Therefore, after secondary heating and cooling, the refractory material 21 becomes a pseudo-cured solid-state coating film, and the obtained coating films 11X, 12X, 13X have excellent mechanical strength and the like. In the secondary heating, the refractory material 21 may be heated to about 80 to 180°C, preferably 100 to 160°C. Further, the secondary heating may be performed until the particle shape of the thermoplastic resin in the refractory material 21 disappears. There is no limitation on the heating time, but it may be performed for about 1 to 60 minutes, preferably 2 to 30 minutes. The method of further heating the refractory material 21 on the molding die 10 is not particularly limited. The object to be coated with the refractory material may be put into a heating oven for heating, or it may be heated by hot air, an infrared heater, or the like. The thickness of the coating film formed by the above coating method may be the same as the size described in terms of the thickness of the above-described molding covering material.

[0077] In this embodiment, the dipping tank 20 is configured by providing a sheet-like member 25 on the base member 26, and the refractory material 21 is filled on the sheet-like member 25. As long as the molding core 10 with the coating film formed can be demolded, the sheet-like member 25 may be omitted. Further, a sheet or a film may be provided on the sheet-like member 25, etc., and two or more sheet-like members may be provided, or it may have another configuration. By further providing a sheet or a film, it becomes easier to smooth the surface of the coating film.

[0078] (Demolding step) By the above secondary heating, the pseudo-cured coating films 11X, 12X, and 13X are demolded from the molding core 10 as the molding covering material 50 in the demolding step. Demolding may be performed by peeling the molding covering material 50 from the molding core 10.

[0079] As described above, according to the manufacturing method of this embodiment, the thickness of the coating films 11X, 12X, and 13X is determined by the interval between the outer surface of the molding core 10 and the inner surface 20A of the dipping tank 20, so the thickness of the coating film can be freely designed. Therefore, for example, by making the intervals D1 to D7 between the outer surface of the molding core 10 and the inner surface 20A of the dipping tank 20 constant, it is also possible to form a uniform coating film. In addition, the steel material to be processed generally has size errors. When the above refractory material is directly coated on the steel material to be processed, it is difficult to suppress the variation in the intervals D1 to D7 due to the size errors, and thickness errors are likely to occur. However, in this embodiment, by repeatedly molding the coating material 50 using one molding core mold 10, it is possible to suppress the thickness error of the coating material based on the size error between the steel materials. Furthermore, since the object 60 to be processed can be covered with the refractory coating without moving the object 60 to be processed into the immersion tank 20, the productivity is improved.

[0080] [Second Embodiment] In the above first embodiment, the object 60 to be processed is covered with the molding coating material over the entire outer surface in the cross section, but it is not necessary for the molding coating material to cover all the outer surfaces, and it may not be covered on some of the outer surfaces. For example, in the case of an H-shaped steel, the molding coating material 50 may not be covered on the outer surface 62A of the flange 62. Hereinafter, the case where the molding coating material is not covered on the surface 62A will be described as the second embodiment. In the description of each of the following embodiments, when it is the same as the first embodiment, the description thereof will be omitted.

[0081] The molding coating material 50X in the second embodiment is the same as the first embodiment except that a flat portion 51G for covering the surface 62A is not provided as shown in FIG. 4.

[0082] Also, in this embodiment, in the manufacture of the molding coating material 50X, as shown in FIG. 5, when the molding core mold 10 is immersed in the refractory material 21, the surface 12A of the flange 12 is brought into close contact with the inner surface 20A (the side surface of the concave portion 32) of the immersion tank 20, and the other configurations may be the same as those in the first embodiment. In the second embodiment, by bringing the surface 12A of the flange 12 into close contact with the inner surface 20A of the immersion tank 20, it is possible to prevent the refractory material 21 filled inside the immersion tank 20 from entering between the surface 12A and the inner surface 20A of the immersion tank 20, and it is possible to prevent a coating film from being formed on the surface 12A. Therefore, the obtained molding coating material 50X can also be made without the flat portion 51G.

[0083] [Third Embodiment] In each of the above embodiments, the object 60 to be processed was covered by two formed covering materials in the cross section. However, the object 60 to be processed does not necessarily need to be covered by two formed covering materials in the cross section, and it may be covered by one formed covering material. A specific example thereof will be described below as the third embodiment with reference to FIG. 6.

[0084] In the third embodiment, the formed covering material 50Y includes flat portions 51A to 51F that cover one surface 61A of the web 61 and half of the flanges 62 and 63 other than the surface 62A, and flat portions 51H to 51M that cover the remaining one surface 61B of the web 61 and the remaining half of the flanges 62 and 63 other than the surface 62A, and corners 54 that connect the respective flat portions. In this embodiment, since the formed covering material 50Y can cover the object 60 to be processed with a small number of parts, the workability is further improved.

[0085] A method for manufacturing the formed covering material in the third embodiment will be described with reference to FIG. 7. In the above first and second embodiments, the forming core mold 10 was only immersed once, but in this embodiment, the forming core mold 10 is immersed twice, and as shown in FIG. 6, a formed covering material 50 that can cover the portion other than the surface 62A of the H-shaped steel in the cross section with one sheet can be formed. That is, the dipping process of this embodiment includes a first dipping process of dipping a part of the forming core mold 10 into the refractory material 21 so that a part of the outer surface of the forming core mold 10 is coated, and after performing the first dipping process, another part of the outer surface of the forming core mold 10 coated in the first dipping process is coated. It is preferable to perform a second dipping process of dipping the forming core mold 10 into the refractory material 21. In the first and second dipping processes, it is preferable that the forming core mold 10 is heated as described above.

[0086] Here, the forming core mold 10 which is an H-shaped steel may be immersed and coated half by half in the refractory material 21 inside the dipping tank 20 in each of the first dipping process and the second dipping process. Therefore, in the first dipping process, as shown in FIG. 5 and similar to the second embodiment, coating films 11X, 12X, and 13X are formed on the surface 11A, end faces 12C and 13C, and half of the surfaces 13A, 13B, and 12B of the molding core 10. Then, in the second dipping process, the molding core 10 with coating films 11X, 12X, and 13X formed approximately on half of its surface is dipped from the end faces 12D and 13D as shown in FIG. 7(A), and the refractory material 21 is coated on the surface 11B, end faces 12D and 13D of the molding core 10, and half of the surfaces 13A, 13B, and 12B, and the coating films 11X, 12X, and 13X are formed on these. As a result, as shown in FIG. 7(B), a coating film is formed on the outer surface of the molding core 10 except for the surface 12A. Then, as shown in FIG. 7(B), the coating film is demolded from the molding core 10, and the molding covering material 50Y shown in FIG. 6 can be obtained. As described above, also in this embodiment, the molding covering material 50Y with a uniform thickness can be easily manufactured.

[0087] In addition, in the above-described third embodiment, the molding covering material 50Y that does not cover the surface 62A in the cross section of the workpiece 60 (H-shaped steel) has been described. However, similar to the first embodiment, it may be a molding covering material that also covers the surface 62A. In that case, when manufacturing the molding covering material, in either the first or second dipping process, as described in the first embodiment, in addition to the other surfaces and end faces, a coating film 12X may also be formed on the surface 12A of the molding core 10. When the coating film 12X is also formed on the surface 12A, a coating film is formed over the entire molding core 10 in the cross section. Therefore, when demolding the coating film (i.e., the molding covering material), it is advisable to make a cut in a part of the coating film and then peel off the coating film (molding covering material) from the molding core 10 for demolding.

[0088] [Fourth Embodiment] In each of the embodiments described above, the immersion tank 20 is used as the female mold of the mold that forms the surface of the coating film by its inner surface 20A. However, it is not necessary for all surfaces of the coating film to be formed by the inner surface 20A of the immersion tank 20. A part of the coating film may be formed by the inner surface 20A of the immersion tank 20, and it may be used as the female mold of a semi-molding mold in which a part of the coating film is not formed by the inner surface 20A of the immersion tank 20. A form in which the immersion tank 20 is used as the female mold of a semi-molding mold will be described below as a fourth embodiment with reference to FIG. 8, taking the case where the molding core 10 is of the H type as an example.

[0089] Also in the fourth embodiment, in the immersion process, similar to the first embodiment, one surface of the web 11 and half of the flanges 12 and 13 are immersed in the refractory material 21 (see FIG. 8(B)). On the other hand, as shown in FIG. 8(A), the internal shape of the immersion tank 30 has a shape that conforms to the shape of the molding core 10 to be immersed, similar to the first embodiment, and has recesses 32 and 33 and a connecting portion 31.

[0090] However, in the fourth embodiment, the immersion tank 20 is not provided with a sheet-like member, and the recesses 32 and 33 and the connecting portion 31 are formed in the base member 26. In this embodiment, as will be described later, the inner surfaces of the recesses 32 and 33 are not used as the mold for forming the coating film, and since it is not necessary to release the flanges 12 and 13 from the recesses 32 and 33, it is not necessary to provide a sheet-like member that is a release sheet.

[0091] As shown in FIG. 8(B), the internal shape of the immersion tank 20 may have a shape that is slightly larger than the molding core 10 so that a predetermined interval is formed between the inner surface 20A of the immersion tank 20 and the outer surface of the immersed molding core 10. That is, as shown in FIG. 8(B), similar to the first embodiment, there may be intervals D1 to D7 between the outer surface of the molding core 10 and the inner surface 20A of the immersion tank 20. Here, the upper surface of the connecting portion 31 is used as a molding die as in the first embodiment, and the coating film 11X may be formed by the upper surface of the connecting portion 31. Therefore, a coating film 11X having a thickness corresponding to the distance D7 between the surface 11A of the web 11 and the upper surface of the connecting portion 31 (i.e., the inner surface 20A of the immersion tank 20) is formed. Therefore, the thickness of the distance D7 is preferably the size corresponding to the coating film 11X, preferably 0.3 to 10 mm, more preferably 0.8 to 8 mm, and still more preferably 1 to 6 mm.

[0092] On the other hand, the inner surfaces of the recesses 32 and 33 are not used as molding dies, and coating films 12X and 12Y smaller than the distances D1 to D6 between the inner surface 20A of the recesses 32 and 33 (immersion tank 20) and the surfaces 12A, 12B, 13A, and 13B of the flanges 12 and 13 are formed. That is, the distances D1 to D6 are larger than the thicknesses of the coating films 12X and 12Y. Specifically, it is preferably 0.5 mm or more, more preferably 1 mm or more, and still more preferably 1.5 mm or more. Further, in the present embodiment, by making the distances D1 to D6 below a certain level, the amount of the refractory material 21 put into the immersion tank 20 can be appropriately suppressed. From such a viewpoint, the distances D1 to D6 are preferably 20 mm or less, more preferably 12 mm or less, and still more preferably 10 mm or less. The distances D1 to D6 may be the same as each other or different from each other.

[0093] Also in this embodiment, the heated molding core 10 is immersed in the refractory material 21 in the immersion step, and by being immersed, heat energy is transferred to the refractory material 21, and the refractory material 21 is gelled to form a coating film having a certain thickness. Further, as described above, the distances D1 to D6 between the outer surfaces of the flanges 12 and 13 and the inner surface 20A of the immersion tank 20 are larger than the thickness of the coating film that can be formed by heat energy. Therefore, the coating films 12X and 13X formed on the outer surfaces of the flanges 12 and 13 become coating films having a certain thickness formed by the above gelation, and the surfaces of the coating films 12X and 13X are surfaces not formed by the inner surface of the immersion tank 20. And the thickness of the coating films 12X and 13X becomes smaller than the distances D1 to D6. On the other hand, the interval D7 is sized to be equal to or less than the thickness of the coating film that can be formed by thermal energy. Therefore, the coating film 11X on the outer surface of the web 11 is formed by the inner surface of the immersion tank 20 (the upper surface of the connecting portion 31) and will have a thickness corresponding to the interval D7. That is, in the present embodiment, the inside of the immersion tank 20 where the molding core 10 and the refractory material 21 are arranged is, in part (i.e., the portion where the web 11 is arranged), slightly larger than the molding core 10 by the thickness of the coating film 11X to be formed. Also, another part (the portion where the flanges 12 and 13 are arranged) is also slightly larger than the molding core 10, but the size exceeds the thickness of the coating films 12X and 13X to be formed.

[0094] The molding core 10 with the coating films 11X, 12X, and 13X formed thereon may be removed from the immersion tank 20. In the present embodiment, the coating films 12X and 13X are not formed by the inner surface 20A of the immersion tank 20, and there is a liquid refractory material 21 between the coating films 12X and 13X and the inner surface 20A of the immersion tank 20. Therefore, the molding core 10 with the coating films 11X, 12X, and 13X formed thereon can be easily removed from the immersion tank 20 by pulling it upward from the immersion tank 20. Also, not all of the refractory material 21 inside the immersion tank 20 is coated on the molding core 10. When the molding core 10 is removed, as shown in Fig. 8(C), a part of the refractory material 21 remains inside the immersion tank 20. The remaining refractory material 21 inside the immersion tank 20 may be used in the next immersion process. The remaining refractory material 21 can be, for example, mixed with virgin refractory material and used to minimize contamination of the refractory material 21 due to repeated use.

[0095] Then, the coating films 11X, 12X, and 13X on the molding core 10 are pseudo-cured by secondary heating in the same manner as in the first embodiment, and the pseudo-cured coating films 11X, 12X, and 13X are demolded from the molding core 10 as the molding covering material 50 in the demolding process (see Fig. 1(D)).

[0096] As described above, in this embodiment, in the production of the molding coating material 50, since the gaps D1 to D6 are larger than the coating films 12X and 13X, even if the position where the molding core 10 is immersed is slightly deviated from the designed position, the coating films 12X and 13X having a certain thickness can be formed. Therefore, since it is not necessary to immerse the molding core 10 after aligning it with high precision, the workability is improved. Also, in this embodiment, since the coating films 12X and 13X are formed by the same coating method (double-sided coating) on the members (flanges 12 and 13) having the same thickness, their thicknesses are substantially uniform. Therefore, by making the size of the interval D7 match the thickness of the coating films 12X and 13X, the thicknesses of the coating films 11X, 12X, and 13X formed on the entire molding core 10 can be made substantially uniform.

[0097] In addition, in the fourth embodiment described above, the coating film 11X on the outer surface of the web 11 is formed by the inner surface 20A of the immersion tank 20, has a thickness corresponding to the interval D7, and the coating films 12X and 13X on the outer surfaces of the flanges 12 and 13 are not formed by the inner surface 20A of the immersion tank 20, and the thicknesses of the coating films 12X and 13X are smaller than the intervals D1 to D6. However, in this embodiment, as long as a coating film having a thickness corresponding to the interval between the outer surface and the inner surface 20A is formed on a part of the outer surface of the molding core 10, and a coating film smaller than the interval between the outer surface and the inner surface 20X is formed on another part of the outer surface of the molding core 10, any aspect may be adopted.

[0098] In addition, in the present embodiment, the immersion tank 20 was used as a semi-molding die for molding the coating film 11X formed on the web 11 with the inner surface 20A (the upper surface of the connecting portion 31). However, the coating film 11X may not be molded by the inner surface 20A, and the immersion tank 20 may not be used as a molding die. That is, in the present embodiment, a refractory coating film smaller than the distance D7 between the surface of the web 11 and the inner surface 20A (the upper surface of the connecting portion 31) of the immersion tank 20 may be formed on the surface of the web 11. In this case, the distance D7 is larger than the thickness of the coating film 11X. Specifically, similar to the distances D1 to D6, it is preferably 20 mm or less, more preferably 12 mm or less, and even more preferably 10 mm or less. The lower limit may be the same as that of the distances D1 to D6 above.

[0099] [Fifth Embodiment] The object 60 to be coated of the present invention is not limited to H-shaped steel and can be applied to various types of steel materials. It can be applied to steel materials of any shape such as round steel, square steel, L-shaped steel, angle steel, and U-shaped steel. Hereinafter, the molding covering material applied in the case of round steel will be described as the molding covering material according to the fifth embodiment with reference to FIGS. 9 and 10.

[0100] Also in the fifth embodiment, the molding covering material 150 preferably has a shape corresponding to the object 160 to be coated, and the molding covering material 150 has a bent shape in accordance with the outer surface of the object 160 to be coated. Further, in the present embodiment, the molding covering material 150 is formed by combining two pieces in the cross section to cover the outer surface of the object 160 to be coated. Therefore, the molding covering material 150 in the present embodiment preferably has a semi-annular shape with respect to each other, and the entire outer surface of the object 160 to be coated is covered by two semi-annular molding covering materials 150 in the cross section.

[0101] Also in the present embodiment, the molding covering material 150 is formed by coating a refractory material on the outer surface of the molding core in the same manner as in the above embodiments. As shown in FIG. 10, the molding core 110 may have any shape corresponding to the object 160 to be coated. Specifically, round steel may be used. Further, similar to each of the above embodiments, the immersion tank 120 may be provided with a space D8 between the inner surface 120A of the immersion tank 120 and the outer surface of the molding core 110 to be immersed, and may have a shape corresponding to the molding core 110. Also, in this embodiment, since the molding coating material 150 is in a semi-annular shape, the inner surface 120A of the immersion tank 120 may also have a semi-circular cross section.

[0102] In this embodiment, the space D8 is preferably less than or equal to the thickness of the coating film that can be formed by thermal energy. Thereby, the coating film 110X formed on the molding core 110 is formed by the inner surface 120A of the immersion tank 20. Therefore, a coating film 110X having a thickness corresponding to the space D8 is formed on the outer surface of the molding core 110. That is, for example, if the space D8 is 5 mm, the thickness of the coating film 110X formed on the surface of the molding core 110 is also approximately 5 mm. Note that the specific preferred range of the space D8 is the same as the spaces D1 to D7 described in the first embodiment, and thus the description thereof is omitted.

[0103] However, the space D8 may be larger than the thickness of the film that can be formed by thermal energy. That is, a coating film 110X having a thickness smaller than the space D8 may be formed on the outer surface 110A of the molding core 110. In the case of round steel, thermal energy is evenly transferred to the surrounding refractory material 21. Therefore, even if the space D8 is made larger than the thickness of the formed coating film 10X, a coating film 110X having a uniform thickness can be formed on the outer surface 110A of the molding core 110.

[0104] Also in this embodiment, the outer surface of the molding core 110 is coated with a refractory material in the same manner as in each of the above embodiments, and the coating film 110X is formed by the coated refractory material 21. As shown in FIG. 10(D), the coating film 110X is demolded from the molding core 110, and thus the molding coating material 150 can also be obtained in this embodiment.

[0105] [Sixth Embodiment] Next, a coating method in the case where the molding core 10 is a square steel will be described as the sixth embodiment. Hereinafter, with reference to FIGS. 11 and 12, a molding coating material according to the sixth embodiment and a manufacturing method thereof will be described. Also in the sixth embodiment, the molding coating material 250 preferably has a shape corresponding to the object 260 to be processed, and in the cross section, two are combined to cover the outer surface of the object 260 to be processed. The molding coating material 250 in the present embodiment preferably has a U-shape with respect to each other, and the entire outer surface of the object 260 to be processed is covered by two U-shaped molding coating materials 250. Specifically, the molding coating material 250 in the present embodiment has flat portions 250P to 250R and corners 254 connecting the respective flat portions.

[0106] Also in the present embodiment, the molding coating material 250 is formed by coating a refractory material on the outer surface of the molding core 210 in the same manner as in the above embodiments. As shown in FIG. 12, the molding core 210 may have any shape corresponding to the object 260 to be processed, and specifically, square steel may be used. In the sixth embodiment, the immersion tank 220 preferably has a shape corresponding to the object (molding core 210) to be processed such that an interval D9 is provided between the inner surface 220A of the immersion tank 220 and the outer surface of the immersed molding core 10, in the same manner as in the above embodiments. Therefore, the inner surface 220A of the immersion tank 220 is preferably rectangular corresponding to the outer surface of the square steel. However, since the corner portion 210E of the square steel is generally formed by a curved surface, the corner portion 220E of the bottom surface of the immersion tank 210 is also preferably formed by a curved surface in accordance with the corner portion 210E.

[0107] In this embodiment as well, the interval D9 is preferably not greater than the thickness of the film that can be formed by thermal energy. As a result, the coating film 210X is formed by the inner surface 220A of the immersion tank 20, and thus, a coating film 210X having a thickness corresponding to the interval D9 is formed on the outer surface of the molding core 210. That is, for example, if the interval D9 is 5 mm, the thickness of the coating film 210X formed on the surface of the molding core 210 is also approximately 5 mm. Note that the specific preferred range of the interval D9 is the same as the intervals D1 to D7 described in the first embodiment, and thus the description thereof is omitted.

[0108] However, in this embodiment as well, the interval D9 may be greater than the thickness of the film that can be formed by thermal energy. That is, a coating film 210X having a thickness smaller than the interval D9 may be formed on the outer surface 210A of the molding core 210. However, in the case of square steel, the refractory material 21 in contact with the corners receives less thermal energy transferred than the refractory material 21 in contact with the other portions. Therefore, if the interval D9 is increased, the thickness of the coating film 210X at the corners becomes thinner. Thus, in this embodiment, it is preferable that a coating film 210X having a thickness corresponding to the interval D9 is formed on the outer surface of the molding core 210 as shown in FIG. 12. In this embodiment as well, as shown in FIG. 12(D), the coating film 210X is demolded from the molding core 210 to obtain the molded covering material 250.

[0109] In the above fifth and sixth embodiments, the object to be coated is shown in a mode in which two molded covering materials are combined and coated in a cross section. However, in these embodiments as well, a mode in which the object to be coated is coated with a single molded covering material may be employed as in the third embodiment. Further, in each of the above embodiments, the object to be coated is shown in a form in which it is coated with one or two molded covering materials in a cross section. However, in a cross section, it may be coated with three or more molded covering materials.

[0110] [Seventh Embodiment] Next, as a seventh embodiment, an example in which the object to be worked 60 is covered by three formed covering materials 71, 72, and 72 in a cross section when the object to be worked is an H-shaped steel will be described with reference to FIG. 13. In this embodiment, one of the three formed covering materials 71 covers the flange 63 of the H-shaped steel. Specifically, it covers the surfaces 63A, 63B and the end faces 63C, 64D. Therefore, it has flat portions 73A to 73D for covering each of these, and an opening 75 for passing through the web 61 is provided in the flat portion 73B. The flat portions 73A to 73D are connected via corners 74. Both of the formed covering materials 72, 72 cover a part of the web 61 and a part of the flange 62. Specifically, they cover one of the surfaces 61A, 61B of the web 61, the surface 62B of the flange 62, and one of the end faces 62D, 62C of the flange. Therefore, they have flat portions 73E to 73G for covering each of these, and these flat portions 73E to 73G are connected via corners 74. Note that the two formed covering materials 72, 72 may have the same shape to facilitate manufacturing. Also in this embodiment, each of the formed covering materials 71, 72, 72 may be used to cover the object to be worked 60 (H-shaped steel). At that time, the formed covering material 71 may be fitted into the flange 63 through the opening 75.

[0111] In this embodiment, each of the formed covering materials 71, 72, 72 may be formed in the same manner as in the above embodiments by dipping a forming core into a dipping tank to coat the forming core with a refractory material. At this time, the shape of the inner surface of the dipping tank has a shape corresponding to each of the formed covering materials as described above, and the dipping tank serves as the female mold of the forming mold so that the outer surface of the coating film is formed by the inner surface of the dipping tank. For example, as shown in FIG. 14, the dipping tank 80 for molding the molding coating material 71 is configured by the inner surface having a rectangular cross-section according to the flange, and the intervals D11 to D13 between the inner surface 80A of the dipping tank 80 and the molding core 10 (the surface 13A and the end faces 13C, 13D) are preferably sized to be less than or equal to the thickness of the film that can be formed by thermal energy, similar to the intervals D1 to D7 in the first embodiment.

[0112] Furthermore, although the thickness of the coating film 13X on the surface 13B cannot be adjusted by the inner surface 80A of the dipping tank 80, it is preferably adjusted by the height position H of the refractory material 21 filled in the dipping tank 80. That is, the amount of the refractory material 21 (i.e., the liquid level height) is adjusted so that the height difference D14 between the height position H and the plane 13B is less than or equal to the thickness of the film that can be formed by thermal energy, similar to the intervals D1 to D7. By adjusting in this way, the coating film 13X on the plane 13B becomes a coating film with a thickness corresponding to the height difference D14, and the coating film 13X on the surface 13B, as well as on the end faces 13C, 13D and the surface 13A, can be easily adjusted to a desired thickness. However, also in this embodiment, similar to the fourth embodiment, any one or all of the coating films on the surface 13A, the end faces 13C, 13D may not be formed by the inner surface of the dipping tank, and the intervals D11 to D13 may be made larger than the thickness of the film that can be formed by thermal energy. Similarly, the height difference D14 may also be made larger than the thickness of the film that can be formed by thermal energy.

[0113] Note that the dipping tank 80 shown in FIG. 14 includes a sheet-like member 85 and a base member 86 that supports the sheet-like member 85, similar to the first embodiment, and the base member 86 is composed of two members 86A and 86B. A clearance 87 is provided between the two members 86A and 86B, and the members 86A and 86B are displaceable in the left-right direction in FIG. 14. When separating the molding core 10 with the coating film formed from the dipping tank 80, the members 86A and 86B are preferably displaced so as to separate from each other.

[0114] In each of the above embodiments, the immersion tank had a shape corresponding to the molding core 10. However, the immersion tank does not necessarily have to have a shape corresponding to the molding core 10. As shown in FIG. 15, a general immersion tank 95 may be used. When the immersion tank 95 does not have a shape corresponding to the molding core 10, the immersion tank 95 does not have the function as a molding die. However, even if the heated molding core 10 is only immersed in the refractory material 21, the molding core 10 can be coated. Therefore, even when the immersion tank does not have a shape corresponding to the molding core, a coating film can be formed on the surface of the molding core, and the molding coating material can be obtained by demolding the coating film.

[0115] Also, in each of the above-described embodiments, the molding coating material may cover the workpiece by arranging a plurality of sheets in the longitudinal axis direction of the steel material. The steel material as the workpiece has a length of a certain length or more (for example, 1 m or more, more typically 2 m or more and 10 m or less) in the longitudinal axis direction. By covering the workpiece by arranging a plurality of sheets of the molding coating material in the longitudinal direction, even if the workpiece is long, the length per sheet can be reduced. Therefore, it becomes possible to produce industrially without increasing the scale of production equipment such as an immersion tank. The length of the molding coating material is not particularly limited, but from the viewpoints of workability and productivity, for example, it may be about 10 cm to 10 m, preferably 0.5 to 5 m, and more preferably about 1 to 3 m.

[0116] [Eighth Embodiment] In each of the above embodiments, the case where the workpiece is a steel material having a relatively simple surface shape such as an H-shaped steel, a round steel, or an angle steel has been described as an example. However, the present invention is applicable to workpieces having a complicated surface shape. Specifically, examples include connection portions between steel materials in buildings and the like. Hereinafter, a specific example in which the connection portion between steel materials is used as the workpiece will be described as the eighth embodiment. FIG. 16 shows an example in which the steel materials 81 and 81 are H-shaped steels. The connection portion 85 of the steel materials 81 and 81 generally includes a joining material 82 such as a gusset plate and a fixture 83 such as a bolt for fixing the joining material 82 and the steel material 81, and has an uneven shape on the surface. In the following description, the longitudinal axis direction of the steel material is defined as the x direction, the direction perpendicular to the web is defined as the y direction, and the direction perpendicular to the flange is defined as the z direction for explanation.

[0117] FIG. 17 shows the formed coating material 90 of the present embodiment. Note that FIG. 17(A) shows a cross-sectional view along the yz plane, and FIG. 17(B) shows a cross-sectional view along the xy plane. As shown in FIG. 17, the formed coating material 90 that covers the connection portion 85 preferably has a shape corresponding to the outer surface of the connection portion 85. Therefore, it is preferable that convex portions 90B and 90C corresponding to the joining material 82 and the fixture 83 are provided on the base portion 90A that covers the steel material 81. As described above, by using the formed coating material 90 having a shape corresponding to the shape of the connection portion 85, the connection portion 85 of the steel material can also be covered with the formed coating material 90 having fire resistance. Note that, for the steel material 81 other than the connection portion 85, the outer surface thereof is preferably covered with the formed coating material or the like described in the first to seventh embodiments above.

[0118] Next, with reference to FIG. 18, a method for manufacturing the formed coating material according to the present embodiment will be described. Also in the present embodiment, the formed coating material 90 may be formed by immersing a forming core mold in an immersion tank to coat the forming core mold with a refractory material and using the coated refractory material. In the present embodiment, as the forming core mold 100, a mold having the same shape as the object to be constructed may be used in the same manner as in the above embodiments. Therefore, a member corresponding to the connection portion 85 may be manufactured using the steel material 81, the joining material 82, and the fixture 83, and used as the forming core mold 100. Also, when the shape of the object to be constructed is complex as in this embodiment, it is not easy to use the immersion tank as the female mold of the mold. Therefore, as the immersion tank, it is preferable to use an immersion tank 95 that does not have a shape corresponding to the molding core 100. When using the immersion tank 95, it becomes difficult to make the thickness the desired size, and in order to ensure the fire resistance performance, it is necessary to coat it thickly so that it is not less than the minimum thickness. However, since the connection part 95 occupies a small proportion in the building, the increase in cost has little impact on the entire building and there are no practical problems.

[0119] Furthermore, in this embodiment, the coating film formed on the outer surface of the molding core 100 may be made into the molded coating material 90 by demolding from the molding core 100. However, in this embodiment, when the coating film is also formed on both end portions 100A and 100B in the x direction of the molding core 100, the coating film formed on both end portions 100A and 100B may be removed before or after demolding. This is because if there is such a coating film, the molded coating material 90 cannot be applied to the connection part 85. However, the molding core 100 may be immersed in the immersion tank so that the coating film is not formed on both end portions 100A and 100B.

[0120] <Other Modification Examples> The shape of the molded coating material of the present invention is not limited to the above, and any shape may be used as long as at least a part thereof is bent. Also, the corners of the molded coating material are not limited to right angles and may have a shape other than a right angle. Also, in each of the above embodiments, the molded coating material is adhered to the surface of the object to be constructed by an adhesive and covers the object to be constructed. However, the molded coating material may be fixed to the object to be constructed by means other than an adhesive. For example, it may be fixed by a fixture such as a screw.

[0121] The following describes one embodiment of fixing using screws as a modification of the second embodiment with reference to FIG. 19. The screw 108 may be inserted so as to pass through the molded coating material 50X and reach the object to be constructed 60 (steel material). When using the screw 108, a pilot hole may be made in the object to be constructed 60 for insertion, or it may be inserted without making a pilot hole by using a drill screw or the like as the screw 108. Further, when using the screw 108, as shown in FIG. 19, a washer 101 may also be used, and the screw 108 may be inserted through the washer 101 and then through the molded coating material 50X and the object to be constructed 60. Furthermore, as a fixture, instead of a screw, a pin such as a welding pin (not shown) may be used to fix the molded coating material 50X to the object to be constructed 60 by stud welding or the like. In this modification, since the molded coating material 50X can be fixed to the object to be constructed 60 without using an adhesive, the molded coating material can be applied to the object to be constructed with high workability. Note that the embodiment of fixing with screws or pins has been described with reference to the example in FIG. 19 where the object to be constructed is an H-shaped steel and the molded coating material is the molded coating material 50X according to the second embodiment. However, any of the molded coating materials described above may be fixed to the object to be constructed with screws or pins.

[0122] Furthermore, as the fixture, fixtures other than screws and pins may be used. For example, the fixture 102 shown in FIG. 20 may be used. The fixture 102 includes gripping portions 103 and 104, and fixes the sandwiched member by sandwiching it from both sides with the gripping portions 103 and 104. The fixture 102 is formed of metal and is formed by, for example, bending. In the fixture 102, the gripping portion 104 is narrower than the gripping portion 103, and two gripping portions 104 are provided, and each gripping portion 104 is connected to the gripping portion 103 via a connecting portion 105. The fixture 102 is spring-like, with the distance between the gripping portion 103 and the gripping portion 104 decreasing as it moves away from the connecting portion 105. The gripping portion 104 and the gripping portion 103 can sandwich the inner member with a high gripping force due to the restoring force of the spring.

[0123] The fixture 102 may fix the formed coating material to the object to be processed by sandwiching the object to be processed coated with the formed coating material together with the formed coating material from both sides. One embodiment using the fixture 102 is shown in FIG. 21 as a modification of the seventh embodiment. As shown in FIG. 21, the fixture 102 fixes the formed coating material 72 to the flange 62, for example, in the H-shaped steel, by sandwiching the flange 62 and the formed coating material 72 coated on the flange 62 from both sides. On the other hand, the formed coating material 71 inserts the flange 63 therein through the opening 75 and covers the flange 63 fitted inside the formed coating material 71, so that the formed coating material 71 can be fixed to the flange 63 without an adhesive or a fixture. Therefore, in this modification, without using an adhesive and with the fixture 102 being easy to use for fixing, the formed coating material can be fixed to the object to be processed with higher workability.

[0124] In each of the above embodiments, the case where the refractory material contains a resin containing a thermoplastic resin, a plasticizer, and a thermally expandable component and is a plastisol has been described. However, the refractory material is not necessarily limited to the above configuration, and as long as it contains a resin and a thermally expandable component, refractory materials of other configurations may be used. For example, the resin may be a thermosetting resin such as an epoxy resin, a photocurable resin, a moisture-curable resin, etc. without containing a thermoplastic resin. When using other than plastisol, in the manufacturing method of each of the above embodiments, depending on the type of resin and the properties of the refractory material, the heating step and the secondary heating step may be omitted, or steps other than the heating step and the secondary heating step may be appropriately added.

[0125] For example, in the case of a thermosetting resin, a refractory material coated on a molding core by dipping is thermoset to form a coating film on the surface of the molding core, and the coating film is demolded from the molding core to obtain a molding coating material. In the case of a photocurable resin, a refractory material coated on a molding core by dipping is photocured to form a coating film on the surface of the molding core, and the coating film is demolded from the molding core to obtain a molding coating material. In the case of a moisture-curable resin, a refractory material coated on a molding core by dipping is moisture-cured to form a coating film on the surface of the molding core, and the coating film is demolded from the molding core to obtain a molding coating material.

[0126] In each of the above embodiments, the coating of the refractory material on the molding core was performed by dipping, but it may also be performed by other methods than dipping, such as a method of spray coating (spray coating), known coating machines such as coating robots, and a method of applying to the surface of the molding core with a brush or the like. Further, when the required thickness cannot be obtained by a single coating of the refractory material on the molding core, it may be repeated a plurality of times.

[0127] In the above description, an example in which the object to be coated is a steel material has been described, but it may be an object to be coated other than a steel material, such as wood, a metal material other than steel, concrete, brick, concrete block, stone, etc. However, the object to be coated is preferably a metal material such as steel, and more preferably steel. Similarly, a material other than steel may be used for the molding core, but a metal material such as steel is preferred, and steel is more preferred. Metal materials such as steel are easy to heat and hardly deform even when heated. Therefore, for example, by coating a refractory material on a molding core made of heated metal, it becomes easy to form a thick coating film without deforming the molding core.

[0128] The use of the object to be treated is not particularly limited, but it is preferably a member that needs to be protected in case of a fire. Specifically, examples include structural materials of buildings, bodies of various vehicles, etc. That is, the molded coating material of the present invention may be used for structural materials of buildings and bodies of vehicles. Note that a structural material is a member that forms the framework in a building and is a member that bears the forces applied to the building, such as the weight and load of the members constituting the building. The structural materials of building materials are heated during a fire, resulting in a decrease in strength, or the building may collapse due to combustion. However, by covering these surfaces with the molded coating material of the present invention, a heat insulation layer will be formed on these surfaces when a fire occurs. Therefore, heating and combustion are suppressed, and the collapse of the building can be prevented.

[0129] Also, by covering the surfaces of the members constituting the vehicle body with the molded coating material of the present invention, it is possible to prevent a fire from spreading throughout the vehicle when a fire occurs in a part of the vehicle. Therefore, even when a battery such as a lithium-ion battery (LIB) mounted in a vehicle experiences thermal runaway and catches fire due to an internal short circuit or the like, it is possible to prevent the fire from spreading throughout the vehicle. Also, as the vehicle, it may be a vehicle such as an automobile, a train, a steam locomotive, a railway vehicle such as a train, a civil engineering heavy machine such as a forklift or an excavator, a cart, a vehicle in an amusement park, or it may be a vehicle other than a vehicle such as a ship or an airplane. Among these, an automobile is preferred. Also, the refractory material is preferably used for underbody coat applications. Therefore, the object to be treated is preferably the underbody of an automobile.

Explanation of Reference Numerals

[0130] 10, 100, 110, 210 Molding cores 11, 61 Webs 12, 13, 62, 63 Flanges 10X, 11X, 12X, 13X Coating films 11A, 11B, 12A, 12B, 13A, 13B Surfaces (outer surfaces of the object to be treated) 12C, 13C One end faces 12D, 13D Other end face 20, 80, 90, 95, 120, 220 Immersion tank Inner surface of immersion tanks 20A, 120A, 220A 21 Refractory material 50, 50X, 50Y, 72, 73, 150, 250 Formed coating material 51A - 51G Flat part 54 Corner 60, 160, 260 Object to be applied 61A, 61B, 62A, 62B, 63A, 63B Surfaces (outer surfaces of forming cores) 62C, 63C One end face 62D, 63D Other end face 64 Corner part 85 Connection part 102 Fixture 108 Screw D1 - D9, D11 - D13 Predetermined intervals D14 Height difference

Claims

1. A formed coating material formed from a refractory material containing a resin and a thermally expandable component, and at least partially bent.

2. The formed coating material according to claim 1, having at least one corner.

3. The formed coating material according to claim 1, which is sheet-shaped.

4. The formed coating material according to claim 1, wherein the refractory material further contains a plasticizer.

5. The formed coating material according to claim 4, wherein the refractory material is a plastisol in which the resin is dispersed in a sol state in the plasticizer.

6. The formed coating material according to claim 1, wherein the resin is at least one selected from the group consisting of polyvinyl chloride-based resins and acrylic resins.

7. A refractory coating method of coating a formed coating material according to any one of claims 1 to 6 on an object to be coated.

8. The refractory coating method according to claim 7, wherein the formed coating material is adhered to the surface of the object to be coated.

9. A method for manufacturing a formed coating material according to any one of claims 1 to 6, The method for manufacturing a formed coating material, comprising coating the outer surface of a forming mandrel with the refractory material and forming a formed coating material with the coated refractory material.

Images