JP2024079886A - Coating Method - Google Patents

Abstract

To provide a coating method that can shorten construction time, exhibits superior adhesion, and ensures sufficient heat insulation and fire resistance.SOLUTION: A coating method according to the present invention involves forming a foamable fire-resistant coating layer on a substrate and then spraying to form a urethane foamed layer. The foamable fire-resistant coating layer is formed from a foamable fire-resistant coating material containing crosslinkable resin and fire-resistant powder.SELECTED DRAWING: None

Description

The present invention relates to a coating method.

Traditionally, high insulation is required in freezer/refrigerated warehouses (low-temperature logistics warehouses) due to the large temperature difference between inside and outside the warehouse. In recent years, insulation has also come to be required in general buildings from the perspective of energy conservation, etc. In order to meet such insulation requirements, organic insulation materials are widely used. When using such organic insulation materials, for example, urethane foam containing a flame retardant as in Patent Document 1, and composite insulation materials in which a mortar composition or the like is layered on an organic insulation material such as urethane foam as in Patent Document 2 have been developed for the purpose of improving fire resistance (flame retardancy).

On the other hand, in large warehouses and high-rise buildings, high fire resistance is required for the steel frame structure, which is the main structure. However, while the above-mentioned Patent Documents 1 and 2 can ensure the fire resistance (flame retardancy) of the urethane foam, they do not take into consideration the fire resistance of the steel frame structure, which is the main structure. In order to ensure the fire resistance of the steel frame structure, it is necessary to cover the steel frame with a fire-resistant coating.

JP 2010-270877 A JP 2014-087961 A

Known examples of fire-resistant coating materials include inorganic fire-resistant coating materials whose main components are cement or mortar, and intumescent fire-resistant coating materials that foam when heated.
However, inorganic fire-resistant coating materials have a large coating thickness, and when a urethane foam layer is formed on top of them, the available space is narrowed. In addition, inorganic fire-resistant coating materials require a long time for drying (curing), etc., which may result in a long construction period. On the other hand, foamable fire-resistant coating materials have a smaller coating thickness than inorganic fire-resistant coating materials, and are also advantageous in terms of shortening the construction period, but when urethane foam is sprayed on top of the foamable fire-resistant coating material, there is a risk of insufficient adhesion.
The present invention has been made in consideration of such problems, and aims to provide a coating method that can shorten the construction period, has excellent adhesion, and ensures sufficient insulation and fire resistance.

To solve these problems, the inventors discovered a coating method that can shorten the construction period, has excellent adhesion, and ensures sufficient insulation and fire resistance by forming a specific foamable fire-resistant coating material on a substrate and then spraying a urethane foam layer on it, leading to the completion of the present invention.

That is, the present invention has the following features.
1. A coating method in which a foamable fire-resistant coating layer is formed on a substrate, and then a urethane foam layer is formed by spraying.
The coating method according to the present invention, wherein the intumescent fire-resistant coating layer is formed from an intumescent fire-resistant coating material containing a crosslinkable resin and a fire-resistant powder.
2. The coating method according to 1., wherein the crosslinkable resin contains a polyol compound and a polyisocyanate compound.
3. The coating method according to 1. or 2., wherein the intumescent fireproof coating material has a heating residue of 70% by weight or more.

The coating method of the present invention is a coating method in which an expandable fire-resistant coating layer is formed on a substrate, and then a urethane foam layer is formed by spraying. In the present invention, the expandable fire-resistant coating layer is formed from an expandable fire-resistant coating material containing a cross-linkable resin and a fire-resistant powder, which shortens the construction period, provides excellent adhesion to the urethane foam layer, and ensures sufficient insulation and fire resistance.

The following describes how to implement the present invention.

The coating method of the present invention is characterized by forming a foamable fire-resistant coating layer on a substrate, and then forming a urethane foam layer by spraying. First, each component will be described.

<Substrate>
The substrates to which the present invention is applied are those used in structures such as buildings and civil engineering structures that require fire resistance and thermal insulation, and specifically include various substrates such as columns, beams, walls, floors, roofs, stairs, ceilings, and doors. Examples of such substrates include concrete, mortar, siding boards, extrusion molding boards, gypsum boards, perlite boards, bricks, plastics, wood, metals, steel frames (steel materials), glass, and porcelain tiles. These substrates may have a coating already formed on their surfaces, may have been subjected to some kind of undercoat treatment (rust prevention treatment, flame retardant treatment, etc.), or may have wallpaper attached thereto. The present invention is a coating method that is particularly suitable for enhancing the fire resistance and thermal insulation of steel frames (steel materials), which are the main structure (framework) in refrigerated and frozen warehouses (low-temperature logistics warehouses).

<Intumescent fireproof coating layer>
The foamable fireproof coating layer of the present invention (hereinafter, simply referred to as "fireproof coating layer") is characterized in that it is formed from a foamable fireproof coating material containing a crosslinkable resin and a fireproof powder. The fireproof coating layer of the present invention forms a dense structure (non-foamed body) under normal conditions, and when the surface of the fireproof coating layer is heated to 200°C or higher (more preferably 250°C or higher) due to a fire or the like, the coating foams (expands) and forms a carbonized heat insulating layer. This can increase the fire resistance of the substrate.

The crosslinkable resin (A) (hereinafter also referred to as "component (A)") acts as a binder for forming the fire-resistant coating layer. Component (A) can undergo a crosslinking reaction when dried and cured by combining compounds having reactive functional groups, forming a crosslinked structure in the fire-resistant coating layer. The crosslinked structure formed by such a combination of reactive functional groups can shorten the construction period. Furthermore, even when the urethane foam layer is formed by spraying, excellent adhesion can be ensured and sufficient fire resistance can be exhibited.
Although the mechanism of action is not limited to the following, by forming a crosslinked structure in the fire-resistant coating layer, deterioration and damage of the fire-resistant coating layer caused by the reaction heat during the formation of the urethane foam layer can be suppressed, and sufficient adhesion can be maintained without causing any problems over time. This makes it possible to maintain a stable fire-resistant coating layer, and when the temperature rises due to a fire or the like, sufficient fire resistance can be exhibited.

Examples of combinations of reactive functional groups that cause such crosslinking reactions include hydroxyl and isocyanate groups, carbonyl and hydrazide groups, epoxy and amino groups, aldo and semicarbazide groups, keto and semicarbazide groups, alkoxyl groups, carboxyl and metal ions, carboxyl and carbodiimide groups, carboxyl and epoxy groups, carboxyl and aziridine groups, and carboxyl and oxazoline groups. These can be used alone or in combination of two or more.

In the present invention, it is preferable that component (A) contains a polyol compound (A1) and a polyisocyanate compound (A2). This can improve adhesion to the urethane foam layer.

Examples of the polyol compound (A1) of the present invention include polyether polyols, polyester polyols, acrylic polyols, epoxy-containing polyols, silicone-containing polyols, fluorine-containing polyols, castor oil, castor oil-modified polyols, polycarbonate polyols, polylactone polyols, polybutadiene polyols, polypentadiene polyols, etc., and one or more selected from these can be used.

The polyol compound (A1) is preferably a liquid at 20° C., and each of the polyol compounds (A1) preferably has a viscosity of 0.05 to 10 Pa·s (more preferably 0.1 to 5.0 Pa·s). This makes it easier to obtain the effects of the present invention.
The viscosity of the polyol component is the viscosity measured at 20 rpm (the index value at the fifth rotation) using a BH type viscometer at a temperature of 20° C., and “α to β” is synonymous with “α or more and β or less”.

In the present invention, it is preferable that the polyol compound (A1) contains polyether polyol (a1). The molecular weight of the polyether polyol (a1) is preferably 1000 or more (more preferably 3000 or more and 20000 or less, more preferably 5000 or more and 18000 or less). By containing such a polyether polyol (a1) as the polyol compound (A1), the temperature rise of the fire-resistant coating layer (preferably the coating surface temperature is 200 ° C. or more, more preferably 250 ° C. or more) shows excellent foaming property, and the fire resistance of the substrate can be improved.
In the present invention, the molecular weight of the polyol compound (A1) is a number average molecular weight (Mn), which is a so-called polystyrene-equivalent molecular weight determined by gel permeation chromatography using a polystyrene polymer as a reference.

The polyether polyol (a1) is obtained by addition polymerization of polyhydric alcohols such as trimethylolpropane, glycerin, hexanetriol, pentaerythritol derivatives, sorbitol, and neopentyl glycol with alkylene oxides such as ethylene oxide and propylene oxide. In the present invention, a polymer obtained by addition polymerization of the above polyhydric alcohols with ethylene oxide and/or propylene oxide is preferred, and one having ethylene oxide and/or propylene oxide added to the terminal is more preferred. Furthermore, it is preferable that the above polyether polyol contains a polyether polyol having three or more functional groups having active hydrogen atoms (functional group number 3 or more). In this case, the curing property is excellent, and a fire-resistant coating layer can be stably formed, so that the effect of the present invention is easily obtained. A hydroxyl group is preferred as the functional group having an active hydrogen atom.

The polyether polyol (a1) preferably has a hydroxyl value (solid content) of 3 to 150 mgKOH/g (more preferably 5 to 100 mgKOH/g, even more preferably 7 to 40 mgKOH/g, and most preferably 10 to 30 mgKOH/g). By using such a polyol compound (a1), more excellent foaming properties can be exhibited, and the fire resistance of the substrate can be increased.
In the present invention, the hydroxyl value is a value expressed in mg of potassium hydroxide equivalent to the moles of hydroxyl groups contained in 1 g of solid content (mgKOH/g).

The content of the polyether polyol (a1) is preferably 50% by weight or more and 100% by weight or less (more preferably 60 to 99% by weight, and even more preferably 70 to 98% by weight) based on the total amount of the polyol compound (A1).

In the present invention, it is preferable that the polyol compound (A1) contains a fluorine-containing polyol (a2). This allows the fire-resistant coating layer to have excellent foaming properties when the temperature rises due to a fire or the like, and also allows a stable carbonized insulation layer to be formed by suppressing incineration and shrinkage of the carbonized insulation layer, thereby further improving the fire resistance of the substrate.

Such fluorine-containing polyol (a2) is not particularly limited, but may be obtained, for example, by copolymerizing a fluorine-containing monomer such as a fluoroolefin monomer or a fluoroalkyl group-containing acrylic monomer with a hydroxyl group-containing vinyl monomer and, if necessary, with other polymerizable monomers.

Examples of fluoroolefin monomers include perfluoroolefins such as tetrafluoroethylene, chlorotrifluoroethylene, and hexafluoropropylene, vinyl fluoride, and vinylidene fluoride. Examples of fluoroalkyl group-containing acrylic monomers include perfluoromethyl methacrylate, perfluoroisononylmethyl methacrylate, 2-perfluorooctylethyl acrylate, 2-perfluorooctylethyl methacrylate, and trifluoroethyl acrylate. These can be used alone or in combination of two or more. In the present invention, it is preferable to use one or more selected from tetrafluoroethylene and chlorotrifluoroethylene, and more preferably chlorotrifluoroethylene.

Examples of hydroxyl group-containing vinyl monomers include hydroxyalkyl vinyl ethers such as hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, and hydroxypentyl vinyl ether; hydroxyallyl ethers such as ethylene glycol monoallyl ether, diethylene glycol monoallyl ether, and triethylene glycol monoallyl ether; and hydroxyl group-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, 4-hydroxyethyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. One or more of these can be used.

Other polymerizable monomers include, for example, (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, n-amyl (meth)acrylate, isoamyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, octadecyl (meth)acrylate, and cyclohexyl (meth)acrylate; dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, dimethylamino (meth)acrylate, aminoethyl (meth)acrylate, and diethylaminoethyl (meth)acrylate. Amino group-containing monomers such as ethyl (meth)acrylate; carboxyl group-containing monomers such as acrylic acid, methacrylic acid, crotonic acid, maleic acid or its monoalkyl ester, itaconic acid or its monoalkyl ester, and fumaric acid or its monoalkyl ester; amide-containing monomers such as (meth)acrylamide and ethyl (meth)acrylamide; nitrile group-containing monomers such as (meth)acrylonitrile; epoxy group-containing monomers such as glycidyl (meth)acrylate; aromatic vinyl monomers such as styrene, methylstyrene, chlorostyrene, and vinyltoluene; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, and vinyl pivalate; olefin-based monomers such as ethylene and propylene, and the like can be used alone or in combination as necessary.

As for such a fluorine-containing polyol (a2), the fluorine content in the solid content of the fluorine-containing polyol (a2) is preferably 10 to 50% by weight (more preferably 15 to 40% by weight, and even more preferably 20 to 35% by weight). In addition, the hydroxyl value (solid content) is preferably 5 to 100 mg KOH/g (more preferably 10 to 80 mg KOH/g). Furthermore, the molecular weight [number average molecular weight (Mn)] is preferably 5,000 to 100,000 (more preferably 8,000 to 60,000). By including such a fluorine-containing polyol (a2), when the temperature rises due to a fire or the like, the fire-resistant coating layer exhibits excellent foaming properties and forms a carbonized insulation layer, and incineration and shrinkage can be suppressed even in a high-temperature atmosphere, and the fire resistance of the substrate can be further improved.

The content of the fluorine-containing polyol (a2) is preferably 0.1 to 30% by weight (more preferably 0.5 to 20% by weight, and even more preferably 1 to 10% by weight) in terms of solid content relative to the total amount of the polyol compound (A1). By satisfying this range, the fire resistance of the substrate can be increased and sufficient adhesion with the urethane foam layer can be ensured.

Examples of the polyisocyanate compound (A2) of the present invention include toluene diisocyanate (TDI), 4,4-diphenylmethane diisocyanate (pure-MDI), polymeric MDI, xylylene diisocyanate (XDI), hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), hydrogenated XDI, hydrogenated MDI, etc., or derivatives thereof which have been allophanated, biurated, dimerized (uretdione), trimerized (isocyanurated), adducted, or carbodiimided; and blocked isocyanates which have been blocked with alcohols, phenols, ε-caprolactam, oximes, active methylene compounds, etc., and one or more selected from these can be used.

In the present invention, the polyisocyanate compound (A2) preferably contains hexamethylene diisocyanate (HMDI) and/or its derivatives (hereinafter also referred to as "HMDIs"). The content of the HMDIs is preferably 90% by weight or more (more preferably 95% by weight or more) based on the total amount of the polyisocyanate compound (A2). In addition, an embodiment in which the polyisocyanate compound (A2) consists only of HMDIs is also suitable. In addition, biuret and/or isocyanurate are suitable as derivatives. In such a case, the curing property of the foamable fireproof coating material is excellent, and the process of forming the fireproof coating layer can be shortened. Furthermore, when the temperature of the fireproof coating layer rises, it exhibits better foaming property, and the fireproofness of the substrate can be improved.

In the present invention, the polyisocyanate compound (A2) preferably contains one having an isocyanate group content of 10% by weight or more (preferably 15% by weight or more and 30% by weight or less) in the solid content. In such a case, the foamable fireproof coating material can exhibit excellent curing properties, and a stable fireproof coating layer can be formed.
In the present invention, the isocyanate group content is defined as the content (% by weight) of isocyanate groups contained in the solid content of a polyisocyanate compound, and is a value determined by neutralizing the isocyanate groups with an excess of amine and then performing back titration with hydrochloric acid.

In the present invention, it is preferable that the mixing ratio of the polyol compound (A1) and the polyisocyanate compound (A2) is an NCO/OH equivalent ratio of 1 or more (preferably 1.2 to 3.5, more preferably 1.5 to 3.0). In such a case, the effects of the present invention can be fully exerted.

In the intumescent fireproof coating material of the present invention, the fireproof powder (B) (hereinafter also referred to as "component (B)") is a component that forms a carbonized insulation layer by interacting with component (A) above (e.g., at least one of the following effects: dehydration and cooling effect, non-flammable gas generation effect, carbonization promotion effect, carbonized insulation layer formation effect, etc.) when the temperature rises during a fire or the like. Examples of such component (B) include foaming agent (b1), carbonizing agent (b2), flame retardant (b3), and filler (b4), and the like, and the component (B) contains one or more selected from these.

The foaming agent (b1) imparts a foaming effect to the fire-resistant coating layer due to a temperature rise during a fire or the like. Specifically, the foaming effect is imparted when the surface temperature of the fire-resistant coating layer preferably reaches 200°C or higher. Examples of the foaming agent (b1) include melamine and its derivatives, dicyandiamide and its derivatives, azobistetrazole and its derivatives, azodicarbonamide, urea, and thiourea. These can be used alone or in combination of two or more. The content of the foaming agent (b1) is preferably 10 to 200 parts by weight (more preferably 20 to 150 parts by weight) per 100 parts by weight of the solid content of the polyol compound (A1).

The carbonizing agent (b2) is a dehydration carbonizing agent that forms a carbonized heat insulating layer when the temperature rises during a fire or the like, and carbonizes the (A) component. Examples of the carbonizing agent (b2) include pentaerythritol, dipentaerythritol, trimethylolpropane, starch, casein, and tris(2-hydroxyethyl)isocyanurate. These can be used alone or in combination of two or more. In the present invention, pentaerythritol and dipentaerythritol are particularly preferred because they have excellent dehydration cooling effects and carbonized heat insulating layer forming effects. The content of the carbonizing agent (b2) is preferably 10 to 200 parts by weight (more preferably 20 to 120 parts by weight) per 100 parts by weight of the solid content of the polyol compound (A1).

Examples of the flame retardant (b3) include organic phosphorus compounds such as tricresyl phosphate and diphenyl cresyl phosphate; chlorine compounds such as chlorinated polyphenyl, chlorinated polyethylene, diphenyl chloride, triphenyl chloride, chlorinated paraffin, pentachlorinated fatty acid ester, perchloropentacyclodecane, chlorinated naphthalene, and tetrachlorophthalic anhydride; antimony compounds such as antimony trioxide and antimony pentachloride; phosphorus compounds such as phosphorus trichloride, phosphorus pentachloride, ammonium phosphate, ammonium polyphosphate, melamine phosphate, melamine polyphosphate, melam polyphosphate, melem polyphosphate, boron phosphate, boron polyphosphate, aluminum phosphate, and aluminum polyphosphate; and inorganic compounds such as zinc borate and sodium borate. These can be used alone or in combination of two or more. In the present invention, the flame retardant (b3) preferably contains at least one phosphorus compound selected from, for example, melamine polyphosphate, melam polyphosphate, a melamine-melam-melem double salt, or a complex compound of a melamine-melam-melem double salt of polyphosphate and dimelam pyrosulfate, and further preferably contains these in combination with ammonium polyphosphate. The content of the flame retardant (b3) is preferably 30 to 800 parts by weight (more preferably 50 to 500 parts by weight) per 100 parts by weight of the solid content of the polyol compound (A1).

Examples of fillers (b4) include talc, calcium carbonate, sodium carbonate, aluminum oxide, titanium oxide, zinc oxide, silica, clay, siliceous silica, mica, silica sand, silica powder, quartz powder, barium sulfate, and the like. These can be used alone or in combination of two or more. The content of filler (b4) is preferably 3 to 200 parts by weight (more preferably 5 to 150 parts by weight) per 100 parts by weight of the solid content of the polyol compound (A1).

In addition to the above components, the present invention may also contain metal hydrate (b5), fibers (b6), and the like. The metal hydrate (b5) exhibits endothermic properties due to a dehydration reaction or the like when the temperature rises, and is different from the filler (b4). Examples of such metal hydrate (b5) include aluminum hydroxide and magnesium hydroxide. These may be used alone or in combination of two or more. The average particle size of the metal hydrate (b5) is preferably 0.1 to 20 μm (more preferably 0.2 to 15 μm, even more preferably 0.3 to 8 μm, and most preferably 0.4 to 3 μm). The content of the metal hydrate (b5) is preferably 0.1 to 50 parts by weight (more preferably 0.2 to 30 parts by weight) per 100 parts by weight of the solid content of the polyol compound (A1).

In the present invention, it is preferable to use the filler (b4) and the metal hydrate (b5) in combination. In this case, the content of the metal hydrate (b5) is preferably 0.1 to 20% by weight (more preferably 0.3 to 15% by weight, and even more preferably 0.5 to 10% by weight) relative to the filler (b4). In this case, the foamability, particularly the shrinkage of the carbonized insulation layer at high temperatures, can be suppressed, and a stable carbonized insulation layer can be formed, thereby enhancing the effects of the present invention. The average particle size is measured by a laser diffraction particle size distribution analyzer.

Fiber (b6) can suppress cracking of the fire-resistant coating layer. In addition, fiber (b6) can prevent sagging of the fire-resistant coating layer when the temperature rises due to a fire or the like, and can increase the thermal conductivity inside the fire-resistant coating layer. As a result, it shows excellent foaming properties, forms a uniform carbonized insulation layer, and can increase the fire resistance of the substrate. Examples of such fibers (b6) include organic fibers such as acrylic fibers, acetate fibers, aramid fibers, cuprammonium fibers (cupra), nylon fibers, novoloid fibers, pulp fibers, viscose rayon, vinylidene fibers, polyester fibers, polyethylene fibers, polyvinyl chloride fibers, polyclar fibers, boronosic fibers, polypropylene fibers, and cellulose fibers (excluding cellulose nanofibers), and inorganic fibers such as carbon fibers, rock wool fibers, glass fibers, silica fibers, alumina fibers, silica-alumina fibers, slag wool fibers, ceramic fibers, carbon fibers, and silicon carbide fibers. These can be used alone or in combination of two or more. In the present invention, it is preferable to include inorganic fibers, and among them, artificial mineral fibers such as rock wool fibers, slag wool fibers, glass fibers, and ceramic fibers are preferable.

The size (fiber length and fiber diameter) of fiber (b6) is preferably in the range of 10 to 1000 μm (more preferably 15 to 800 μm, and even more preferably 20 to 600 μm) for the average fiber length and 0.5 to 10 μm (more preferably 1 to 8 μm) for the average fiber diameter. The aspect ratio (fiber length/fiber diameter) is preferably 3 to 300 (more preferably 5 to 200). The content of fiber (b6) is preferably 0.5 to 30 parts by weight (more preferably 1 to 25 parts by weight, and even more preferably 2 to 20 parts by weight) per 100 parts by weight of the solid content of the polyol compound (A1).

The foamable fireproof coating material of the present invention preferably further contains a high boiling point compound (C) (hereinafter also referred to as "component (C)"). Component (C) is a high boiling point liquid compound that is liquid at 20°C and has a boiling point of 100°C or higher (more preferably 150°C or higher, and even more preferably 200°C or higher). By containing such component (C), the dispersion stability of the above-mentioned component (B) and the like can be improved. In addition, a good fireproof coating layer with excellent adhesion is formed, and in particular, the elasticity of the fireproof coating layer is improved, and the conformity with the urethane foam layer is improved, and peeling and cracking can be prevented. Furthermore, when exposed to high temperatures due to a fire or the like, it contributes to moderate softening of the fireproof coating layer, further increasing the foaming property, suppressing the falling off (peeling) of the formed carbonized insulation layer, and improving the fire resistance of the substrate.

The component (C) is not particularly limited as long as it satisfies the above requirements, and examples thereof include phthalate ester compounds such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, dihexyl phthalate, di-2-ethylhexyl phthalate, diisononyl phthalate, diisodecyl phthalate, diundecyl phthalate, and butyl benzyl phthalate; diethyl adipate, dibutyl adipate, diisobutyl adipate, dihexyl adipate, di-2-ethylhexyl adipate, dioctyl adipate, diisononyl adipate, diisodecyl adipate, bis(butyl diglycol adipate), diethyl sebacate, dibutyl sebacate, and dihexyl sebacate. aliphatic dibasic acid ester compounds such as di-2-ethylhexyl sebacate; adipic acid polyesters such as 1,3-butylene glycol adipic acid polyester and 1,2-propylene glycol adipic acid polyester; maleic acid ester compounds such as dimethyl maleate, diethyl maleate, dibutyl maleate, dihexyl maleate, di-2-ethylhexyl maleate, diisononyl maleate, and diisodecyl maleate; phosphate ester compounds such as triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, and 2-ethylhexyl diphenyl phosphate;

Trimellitic acid ester compounds such as tris-2-ethylhexyl trimellitate; ricinoleic acid ester compounds such as methyl acetyl risinolate; epoxy ester compounds such as di-2-ethylhexyl epoxyhexahydrophthalate, diepoxystearyl epoxyhexahydrophthalate, epoxidized fatty acid butyl, epoxidized fatty acid 2-ethylhexyl, epoxidized soybean oil, and epoxidized linseed oil; benzoic acid ester compounds such as benzoic acid glycol ester; aromatic hydrocarbon compounds such as 1-phenyl-1-xylylethane and 1-phenyl-1-ethylphenylethane; lactones such as γ-butyrolactone; and mixtures of petroleum resins (polymers of aromatic hydrocarbon fractions having 8 to 10 carbon atoms) and styrylxylene. These can be used alone or in combination of two or more.

In the present invention, the component (C) preferably contains one or more compounds selected from phthalate ester compounds, aliphatic dibasic acid ester compounds, and phosphate ester compounds, and more preferably contains one or more compounds selected from phthalate ester compounds and aliphatic dibasic acid ester compounds having an alkyl group with 4 to 11 carbon atoms (more preferably 5 to 10, and even more preferably 6 to 9). Specific examples of suitable compounds include diisononyl phthalate and diisononyl adipate.

The content of component (C) is preferably 5 to 150 parts by weight (more preferably 8 to 100 parts by weight, and even more preferably 10 to 80 parts by weight) per 100 parts by weight of the solid content of polyol compound (A1). When the above range is satisfied, the dispersibility of component (B) is increased, and when the temperature rises due to a fire or the like, the component has excellent foaming properties and can fully exert the effect of maintaining the fire resistance of the substrate.

Other additives may be used as long as they do not significantly impair the effects of the present invention, and examples of such additives include pigments, wetting agents, water absorbents, dehydrating agents, plasticizers, lubricants, preservatives, antifungal agents, anti-algae agents, antibacterial agents, thickeners, anti-sagging agents, viscosity adjusters, leveling agents, dispersants, defoamers, crosslinking agents, curing catalysts, silane coupling agents, UV absorbers, light stabilizers, antioxidants, halogen scavengers, dilution solvents, etc.

The intumescent fire-resistant coating material of the present invention has a heating residue of preferably 70% by weight or more (more preferably 75 to 98% by weight (more preferably 80 to 95% by weight)). When the heating residue of the intumescent fire-resistant coating material satisfies the above range, good coating workability can be obtained and thick coating is also possible, so that the construction period can be shortened. Furthermore, even when the urethane foam layer is formed by spraying, deterioration and damage to the fire-resistant coating layer can be suppressed and excellent adhesion can be ensured. This makes it possible to further improve fire resistance.
The heating residue of the intumescent fireproof coating material is a value measured by the method of JIS K 5601-1-2, the heating temperature being 105° C. and the heating time being 60 minutes.

In the present invention, the viscosity of the intumescent fireproof coating material is preferably 5 to 70 Pa·s (more preferably 7 to 60 Pa·s, and even more preferably 10 to 50 Pa·s). When the viscosity of the intumescent fireproof coating material satisfies the above range, excellent coating workability can be achieved, and a uniform coating can be formed. As a result, sufficient fire resistance can be obtained. The viscosity of the intumescent fireproof coating material is the viscosity at 20 rpm (guideline value at the fifth revolution) measured with a BH type viscometer at a temperature of 23°C immediately after the intumescent fireproof coating material is prepared (after mixing the base agent and hardener in the case of a two-component type).

In the present invention, a fire-resistant coating layer having a desired thickness can be formed by applying an expandable fire-resistant coating material that satisfies the above heating residue and viscosity range. Furthermore, the fire-resistant coating layer exhibits excellent expandability when the temperature rises due to a fire or the like, and forms a carbonized insulating layer, thereby maintaining the fire resistance of the substrate.

The foamable fireproof coating material of the present invention is preferably a two-liquid coating material having a base agent containing the above polyol compound (A1) and a curing agent containing the above polyisocyanate compound (A2). That is, during distribution, the base agent and the curing agent are stored in separate packages, and are mixed at the time of use (application). In this case, the fireproof powder (B), (and, if necessary, the high boiling point compound (C), and additives) may be mixed into at least one of the base agent and the curing agent, but in the present invention, it is preferable to mix them into the base agent. Also, each component can be added when mixing the base agent and the curing agent.

<Urethane foam layer>
The urethane foam layer of the present invention forms a foam layer under normal conditions and provides heat insulation, and is formed, for example, from a curable composition containing a polyol compound, a blowing agent, a catalyst, a foam stabilizer, and a polyisocyanate compound. The foam layer formed from such a curable composition is preferably a rigid polyurethane foam layer, and more preferably a rigid polyisocyanurate foam layer.

Examples of the polyol compound include polyester polyols, polyether polyols, polycarbonate polyols, polylactone polyols, polybutadiene polyols, polypentadiene polyols, castor oil polyols, and the like. One or more of these can be used.
The hydroxyl value of the polyol compound in the present invention is not particularly limited, but is desirably 50 mgKOH/g or more and 500 mgKOH/g or less.

Examples of foaming agents include hydrocarbons, hydrochlorofluorocarbons, hydrofluorocarbons, hydrofluoroolefins, hydrochlorofluoroolefins, water, liquefied carbon dioxide gas, etc., and one or more of these can be used. In the present invention, it is preferable to use hydrofluoroolefins. This can improve adhesion to the fire-resistant coating layer.

Examples of hydrofluoroolefins (HFOs) include pentafluoropropenes such as 1,2,3,3,3-pentafluoropropene (HFO1225ye), tetrafluoropropenes such as 1,3,3,3-tetrafluoropropene (HFO1234ze), 2,3,3,3-tetrafluoropropene (HFO1234yf), and 1,2,3,3-tetrafluoropropene (HFO1234ye), and 3,3,3-trifluoropropene ( Examples of the hydrochlorofluoroolefins (HCFOs) include 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd), 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), dichlorotrifluoropropene (HCFO1223), and the like, as well as isomers thereof (cis and trans forms).

The foaming agent in the present invention may contain water. In this case, the content of water is preferably 0.5% by weight or more and 5% by weight or less (more preferably 0.8% by weight or more and 4% by weight or less) based on the total amount of foaming agent. In such a case, there is no risk of deterioration or damage to the fire-resistant coating layer, and a foam layer with excellent heat insulation properties, etc. can be formed while maintaining excellent adhesion.

The amount of foaming agent mixed is preferably 10 to 200 parts by weight (more preferably 20 to 180 parts by weight) per 100 parts by weight of the polyol compound.

The catalyst is not particularly limited, but examples thereof include nurate catalysts, foam catalysts, resinification catalysts, etc., and one or more of these can be used.
The nurate catalyst is not particularly limited as long as it is a catalyst effective for isocyanuration, and examples thereof include hydroxides of tetraalkylammonium such as tetramethylammonium, tetraethylammonium, tetrabutylammonium, and trimethylbenzylammonium, or organic acid salts thereof (organic acids include, for example, acetic acid, caproic acid, octylic acid, myristic acid, and lactic acid), hydroxides of trialkylhydroxyalkylammonium such as trimethylhydroxypropylammonium, trimethylhydroxyethylammonium, triethylhydroxypropylammonium, and triethylhydroxyethylammonium, or organic acid salts thereof, metal salts of alkylcarboxylic acids (for example, acetic acid, caproic acid, octylic acid, myristic acid, and lactic acid), metal chelate compounds of β-diketones such as aluminum acetylacetone and lithium acetylacetone, Friedel-Crafts catalysts such as aluminum chloride and boron trifluoride, organometallic compounds such as titanium tetrabutylate and tributylantimony oxide, and aminosilyl group-containing compounds such as hexamethylsilazane, and the like. One or more of these may be used.
Examples of the foaming catalyst include tertiary amines or organic acid salts thereof such as N,N,N',N',N''-pentamethyldiethylenetriamine, bis(2-dimethylaminoethyl)ether, N,N,N',N',N''-pentamethyldipropylenetriamine, N,N-dimethylaminoethoxyethanol, N,N,N'-trimethylaminoethoxyethanol, N,N,N',N'',N''',N''-hexamethyltriethylenetetramine, N,N,N',N''-tetramethyl-N''-(2-hydroxylethyl)triethylenediamine, and N,N,N',N''-tetramethyl-(2-hydroxylpropyl)triethylenediamine, and one or more of these can be used.
Examples of the resinification catalyst include tertiary amines or organic acid salts thereof such as triethylenediamine (TEDA), triethylenediamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylhexamethylenediamine, N,N,N',N'-tetramethylpropylenediamine, N,N,N',N'',N''-pentamethyl-(3-aminopropyl)ethylenediamine, N,N,N',N'',N''-pentamethyldipropylenetriamine, N,N,N',N'-tetramethylguanidine, and 135-tris(N,N-dimethylaminopropyl)hexahydro-S-triazine; bismuth tris(2-ethylhexanoate), bismuth tris(neodecanoate), bismuth tris(palmitate), and bismuth tetramethylheptanedioate; Examples of the organic metals include bismuth naphthenate, dibutyltin dilaurate, dibutyltin dimaleate, dibutyltin diacetate, dioctyltin diacetate, and tin octylate; imidazoles such as 1-methylimidazole, 2-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-isopropylimidazole, and 1-isobutyl-2-methylimidazole; and N-methyl-N'-(2-dimethylaminoethyl)piperazine, N,N'-dimethylpiperazine, N-methylpiperazine, N-methylmorpholine, N-ethylmorpholine, 1,8-diazabicyclo[5.4.0]undecene-7, and 1,1'-(3-(dimethylamino)propyl)imino)bis(2-propanol). One or more of these can be used.

The amount of catalyst mixed (in terms of active ingredient) is preferably 0.1 to 40 parts by weight, more preferably 0.5 to 30 parts by weight, based on 100 parts by weight of the polyol compound. When the catalyst contains an active hydrogen-containing component, the isocyanate index is calculated taking into account the active hydrogen-containing component contained in the catalyst.
In the present invention, it is desirable to contain a foaming catalyst and/or a resinification catalyst together with the nurate catalyst as the catalyst, and it is particularly desirable to contain a foaming catalyst and a resinification catalyst together with the nurate catalyst.

Examples of foam stabilizers include silicone-based foam stabilizers such as polyether-modified silicone compounds, and fluorine-containing compound-based foam stabilizers. These can be used alone or in combination of two or more. Examples of polyether-modified silicone compounds include graft copolymers of polydimethylsiloxane and polyoxyethylene glycol or polyoxyethylene-propylene glycol. The amount of foam stabilizer mixed is preferably 0.1 to 40 parts by weight, more preferably 0.5 to 30 parts by weight, per 100 parts by weight of the polyol compound.

As the polyisocyanate compound, various polyisocyanate compounds known in the technical field of polyurethane can be used. Examples of polyisocyanate compounds include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HMDI), etc. In the present invention, MDI is preferred in terms of ease of handling, reaction speed, physical properties of the resulting foam, and cost advantages. Examples of MDI include monomeric MDI and polymeric MDI (polymethylene polyphenylisocyanate).

In the curable composition of the present invention, it is desirable to mix the polyol compound and the polyisocyanate compound so that the isocyanate index is preferably 150 or more, more preferably 180 to 800, even more preferably 200 to 500, and most preferably 250 to 400. If the isocyanate index is within such a range, it is preferable in terms of fire resistance, etc. The isocyanate index is expressed as 100 times the value obtained by dividing the number of equivalents of isocyanate groups in the polyisocyanate compound by the total number of equivalents of active hydrogen in the active hydrogen-containing components (polyol compound, water, etc.).

In addition to the above components, the curable composition of the present invention may contain, for example, a flame retardant, a colorant, a surfactant, a polymerization inhibitor, fibers, and the like.
Examples of the flame retardant include phosphorus-based flame retardants, halogen-based flame retardants, organic bromine-based flame retardants, nitrogen-based flame retardants, and metal hydrate-based flame retardants.
Examples of colorants include pigments and dyes.
Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, etc. Such surfactants can impart storage stability and dispersion stability.
Examples of the polymerization inhibitor include hydroquinone-based polymerization inhibitors, benzoquinone-based polymerization inhibitors, catechol-based polymerization inhibitors, piperidine-based polymerization inhibitors, etc. Such polymerization inhibitors impart long-term storage stability to the two-liquid type described below, and also contribute to production stability when added during the polyol production process.
Examples of the fibers include organic fibers, inorganic fibers, etc. Such fibers can impart workability, foam formability, dimensional stability, etc.

It is desirable that the curable composition of the present invention be in the form of a two-part type during distribution, and be mixed when used (when forming a foam layer). In such a two-part type, for example, the first part may contain a polyol compound, a blowing agent, a catalyst, and a foam stabilizer, and the second part may contain a polyisocyanate compound.

<Coating method>
The coating method of the present invention comprises the steps of:
(1) A step of applying the intumescent fire-resistant coating material to a substrate to form an intumescent fire-resistant coating layer;
(2) spraying and foaming the curable composition to form a urethane foam layer;
It includes.

In the above (1), the method of applying the foamable fireproof coating material is not particularly limited, and various methods such as brush coating, roller coating, and spray coating (air spray, airless spray) can be used. In particular, roller coating and spray coating (air spray, airless spray) are easy to apply and can form a coating with excellent finish.

When applying the intumescent fireproof coating material of the present invention to a substrate, it is sufficient to apply the material by one or several recoating steps according to the above method. Even when the intumescent fireproof coating material of the present invention is applied so that the dry film thickness per step exceeds 1000 μm, it is possible to obtain excellent curing properties and adhesion to the substrate, and form a coating with excellent fire resistance. The thickness of the fireproof coating layer finally formed may be appropriately set depending on the desired functionality, application site, etc., but is preferably about 0.4 to 8 mm. In addition, the intumescent fireproof coating material of the present invention may be dried preferably at room temperature, and the interval between the next steps may be preferably 2 hours or more (more preferably 3 hours or more and 30 days or less). In particular, in the present invention, the interval between the above steps (1) and (2) may be 24 hours or less (even 20 hours or less).

In the above (2), when the curable composition is applied onto the foamable fireproof coating layer, the curable composition is preferably sprayed onto the entire foamable fireproof coating layer to foam it, forming a urethane foam layer. The curable composition may be applied, for example, by spraying a mixture of the first and second liquids using a spray foaming machine for spraying work (for example, a two-liquid tip-mixing spray coater, etc.). In this case, it is preferable to set the temperatures of the first and second liquids to about 20 to 60°C, more preferably about 30 to 50°C. The first and second liquids thus set to a predetermined temperature are mixed at the spray tip and sprayed toward the substrate to form a foam on the substrate. It is desirable to mix the first and second liquids at a volume ratio of about 1:1. The foam layer formed in this manner can exhibit excellent performance in terms of low thermal conductivity, fire resistance, etc. The thickness of the foam layer is not particularly limited and may be set appropriately depending on the required performance, etc., but is preferably 10 mm or more, more preferably about 15 to 700 mm. In addition, in the present invention, an intermediate coating material or the like can be applied onto the fire-resistant coating layer before the above step (2). This invention is suitable for forming a urethane foam layer by spraying the curable composition directly onto the fire-resistant coating layer.

In the covering method of the present invention, in order to improve the fire resistance and aesthetics of the urethane foam layer, after the above step (2),
(3) A step of applying an inorganic coating material onto the urethane foam layer (surface) to form an inorganic coating layer;
may include.

The inorganic coating material contains an inorganic binder.
Examples of the inorganic binder include hydraulic inorganic substances, reactive silicon compounds, silicon resins, etc. Examples of the hydraulic inorganic substances include portland cement, alumina cement, ultra-fast hardening cement, expansion cement, acidic phosphate cement, silica cement, lime-mixed cement, blast furnace cement, fly ash cement, Keens cement, magnesia cement, dolomite, hydraulic lime, gypsum, etc. Examples of the reactive silicon compounds include water glass, alkoxysilanes, etc. Examples of the silicon resin include silicones, etc. These can be used in combination of one or more kinds. When a hydraulic inorganic substance is used as the inorganic binder, a color based on the hydraulic inorganic substance can be imparted.

In the inorganic coating material of the present invention, a desired color tone can be imparted by mixing a color pigment. Examples of color pigments include titanium oxide, zinc oxide, aluminum oxide, carbon black, graphite, black iron oxide, copper chrome black, iron chrome black, cobalt black, copper manganese iron black, red iron oxide, molybdate orange, permanent red, permanent carmine, anthraquinone red, perylene red, quinacridone red, yellow iron oxide, titanium yellow, fast yellow, benzimidazolone yellow, chrome green, cobalt green, phthalocyanine green, ultramarine blue, Prussian blue, cobalt blue, phthalocyanine blue, quinacridone violet, and dioxazine violet. These can be used alone or in combination of two or more.

In addition to the above components, the inorganic coating material may contain, for example, extender pigments such as heavy calcium carbonate, clay, kaolin, talc, precipitated barium sulfate, barium carbonate, white carbon, diatomaceous earth, inorganic aggregates such as silica sand, kansui stone, inorganic lightweight aggregates such as perlite, expanded vermiculite, endothermic substances such as aluminum hydroxide, magnesium hydroxide, zeolite, halloysite, allophane, ettringite, inorganic fibrous substances such as glass fiber, steel fiber, etc. Furthermore, as long as the effects of the present invention are not significantly impaired, organic binders such as chloroprene rubber, butadiene rubber, acrylic resin, vinyl acetate resin, epoxy resin, etc., organic lightweight aggregates such as styrene resin foam, ethylene vinyl acetate resin foam, polyvinyl chloride resin foam, etc.
Organic fiber materials such as vinylon fiber and pulp fiber; other additives such as thickeners, defoamers, water-reducing agents, expansion agents, setting accelerators, and surfactants can also be mixed.

When applying the inorganic coating material, a suitable application tool such as a trowel, spray, roller, or brush can be used. The thickness of the inorganic coating layer formed can be set appropriately depending on the application area, application, required performance, etc., but is preferably about 0.2 to 20 mm, and more preferably about 0.5 to 15 mm.

<Fire-resistant structure>
The fire-resistant structure obtained by the coating method of the present invention has an expandable fire-resistant coating layer and a urethane foam layer laminated on a substrate, and preferably has the entire expandable fire-resistant coating layer formed on the substrate coated with the urethane foam layer (the entire expandable fire-resistant coating layer is coated with the urethane foam layer), and has excellent heat insulation and fire resistance.
Specifically, the fireproof structure can ensure sufficient heat insulation under normal conditions, and when the fireproof structure is exposed to high temperatures due to a fire or the like, the urethane foam layer shrinks, while the expandable fireproof layer expands to form a carbonized heat insulating layer, thereby ensuring the fire resistance of the base material.

The following examples will clarify the features of the present invention. However, the present invention is not limited to these examples.

The following fire-resistant coating materials were used to form the fire-resistant coating layer.
(Intumescent fireproof coating material 1)
A base resin was prepared by mixing 100 parts by weight of polyether polyol [solid content 100% by weight, number average molecular weight 7000, functionality 3, hydroxyl value 24 mg KOH/g] with 85 parts by weight of melamine, 60 parts by weight of pentaerythritol, 250 parts by weight of ammonium polyphosphate, 55 parts by weight of titanium oxide, 25 parts by weight of diisononyl phthalate (boiling point 420°C), 90 parts by weight of dilution solvent [aromatic hydrocarbon], and 10 parts by weight of additives [curing catalyst, thickener, dispersant, etc.] in a conventional manner.
As a curing agent, biuret type hexamethylene diisocyanate (NCO content 23.5%) was used.
The above base agent and the above curing agent were mixed so that the NCO/OH equivalent ratio was 1.5, and this was used as intumescent fire-resistant coating material 1 (heating residue 85% by weight).

(Intumescent fireproof coating material 2)
250 parts by weight of acrylic resin (vinyl toluene-acrylic acid ester copolymer, solid content 40% by weight), 85 parts by weight of melamine, 60 parts by weight of pentaerythritol, 250 parts by weight of ammonium polyphosphate, 55 parts by weight of titanium oxide, and 10 parts by weight of additives [curing catalyst, thickener, dispersant, etc.] were mixed in a conventional manner to obtain foamable fireproof coating material 2 (heating residue 77% by weight).

(Non-foaming fireproof coating material)
A composition consisting of 100 parts by weight of Portland cement, 300 parts by weight of aluminum hydroxide, 15 parts by weight of ethylene vinyl acetate-based reemulsifiable powder resin, 30 parts by weight of expanded vermiculite, and 6 parts by weight of glass fiber was mixed with water to prepare a non-foaming fire-resistant coating material.

The following composition was used as the curable composition for forming the urethane foam layer.
(Curable Composition)
A first liquid was prepared by mixing 100 parts by weight of aromatic polyester polyol [terephthalic acid-based polyester polyol, viscosity 1900 mPa·s, acid value: 0 mg KOH/g, hydroxyl value: 250 mg KOH/g], 2 parts by weight of a nurate catalyst, 2 parts by weight of a resinification catalyst, 6 parts by weight of a foaming catalyst, 40 parts by weight of a phosphorus-based flame retardant, 5 parts by weight of a foam stabilizer, 25 parts by weight of a hydrofluoroolefin, and 0.8 parts by weight of water.
As the second liquid, polymeric MDI was prepared.

(Test Examples 1 to 3)
A fire-resistant coating material was applied to the entire surface of a steel plate (100 mm long x 100 mm wide x 6 mm thick) that had previously been coated with an anti-rust paint, and the plate was cured at room temperature (25°C) (the curing period is shown in Table 1) to form a fire-resistant coating layer.
Next, after the fire-resistant coating layer had hardened, the first and second liquids of the curable composition were each heated to 40° C. and mixed so that the isocyanate index was 400. The resulting mixture was sprayed with a spray gun and foamed to form a urethane foam layer (maximum thickness of 30 mm per spray, total thickness of 200 mm), and then cured at room temperature (25° C.) for 3 days to obtain a test specimen.

The obtained test specimens were subjected to the following evaluations. The combinations of the intumescent fire-resistant coating materials and the curable compositions, and the evaluation results are shown in Table 1.
<Adhesion 1>
A jig was attached to the surface (urethane foam layer) of the obtained test specimen with an adhesive, and the maximum tensile load (adhesion strength: N/mm ² ) until breakage at room temperature (25° C.) was measured using a tensile tester to confirm the state of breakage. The evaluation criteria are as follows.
◎: 0.3 N/mm2 ^or more, rupture inside the urethane foam layer ○: 0.3 N/mm2 ^or more, rupture at the interface between the urethane foam layer and the fire-resistant coating layer △: 0.3 N/mm2 ^or more, rupture inside the fire-resistant coating layer ×: 0.3 N/ ^mm2 or less, rupture inside the fire-resistant coating layer <Adhesion 2>
The obtained test specimens were aged at 50° C. for one month and then subjected to the same tests as above.

<Thermal insulation>
The thermal conductivity of the obtained test specimen was measured using a thermal conductivity meter. The evaluation criteria were as follows:
○: Thermal conductivity is 0.026 W/(m.K) or less △: Thermal conductivity is greater than 0.026 W/(m.K) and less than 0.03 W/(m.K) ×: Thermal conductivity is greater than 0.03 W/(m.K)

<Fire resistance>
The obtained test specimen was subjected to radiant heat of 50 kW/ ^m2 for 60 minutes using an electric heater (CONEIII, manufactured by Toyo Seiki Co., Ltd.) based on the ISO 5660-1 cone calorimeter method, and the steel plate backside temperature was measured. The evaluation criteria are as follows.
○: Less than 550°C △: 550°C or higher, less than 600°C
?: 600℃ or higher

Claims (3)

This is a coating method in which an intumescent fire-resistant coating layer is formed on a substrate, and then a urethane foam layer is formed by spraying,
The coating method according to the present invention, wherein the intumescent fire-resistant coating layer is formed from an intumescent fire-resistant coating material containing a crosslinkable resin and a fire-resistant powder. The coating method according to claim 1, characterized in that the crosslinkable resin contains a polyol compound and a polyisocyanate compound. 3. The coating method according to claim 1, wherein the intumescent fire-resistant coating material has a heating residue of 70% by weight or more.