Film formation method

Abstract

To provide a film formation method which is excellent in film curability without depending on a coating environment, can stably secure film performance, and forms a film that can exhibit excellent foamability and maintain heat resistant protection performance of a base material, in the case of a rise of a temperature due to fire.SOLUTION: A film formation method is for forming a film by applying a coating material onto a base material under a high humidity condition, wherein the coating material is a coating material forming a carbonized heat insulation layer by raising its temperature to 200°C or higher, the coating material contains a polyol compound, a polyisocyanate compound, heat resistant imparting powder, and a water absorbent, and a mixing ratio of the polyol compound and the polyisocyanate compound is 1.2 to 3.5 in an equivalent ratio of NCO / OH.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a novel coating material and a film-forming method.

Background Art

[0002] For the purpose of protecting base materials such as steel materials, concrete, wood, and synthetic resins from fire, various coating materials that foam due to a temperature rise during a fire or the like and form a carbonized heat-insulating layer have been proposed. As such a coating material, a material obtained by blending a blowing agent, a carbonizing agent, a flame retardant, etc. into a synthetic resin is known. In many cases, the heat-resistant protection performance of such a coating material is determined by its film thickness, and in order to obtain the desired heat-resistant protection performance, it is important to apply it uniformly with a predetermined film thickness. Among them, the selection of the synthetic resin is important.

[0003] For example, as a coating material for thick coating, a coating material obtained by blending a flame retardant, a blowing agent, and a carbonizing agent into a composition composed of a polyol compound and a polyisocyanate compound has been developed (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the case of the above Patent Document 1, when compared with coating materials using acrylic resin or epoxy resin as the synthetic resin, the foaming ratio of the coating film during temperature rise is low, and furthermore, problems such as ash formation and shrinkage of the carbonized heat-insulating layer (foamed layer) occur. There is still room for improvement to obtain the desired heat-resistant protection performance. In addition, it is necessary to respond to changes in the painting environment due to recent climate change and rapid weather changes. However, depending on the painting environment, the curability of the coating film is inferior, it is difficult to obtain the coating film performance, and it may be difficult to obtain sufficient heat-resistant protection performance. The present invention has been made in view of such problems, and regardless of the painting environment, it has excellent curability of the coating film, can stably ensure the coating film performance, and can form a stable carbonized heat-insulating layer when the temperature rises, and aims to provide a coating material capable of ensuring excellent heat-resistant protection performance.

Means for Solving the Problems

[0006] In order to solve such problems, the present inventors have found that a coating material in which the coating film forms a carbonized heat-insulating layer due to a temperature rise during a fire or the like contains a polyol compound and a polyisocyanate compound in a specific mixing ratio, and further contains a heat resistance-imparting powder and a water absorbent. Regardless of the painting environment, it has excellent curability of the coating film, can stably ensure the coating film performance, and further, the formed coating film exhibits excellent foaming properties when the temperature rises due to a fire or the like, forms a carbonized heat-insulating layer, and can maintain the heat-resistant protection performance of the base material, leading to the completion of the present invention.

[0007] That is, the present invention has the following characteristics. 1. A film-forming method for forming a film by applying a coating material to a base material, wherein the coating material is a coating material in which the coating film forms a carbonized heat-insulating layer when the temperature rises to 200 °C or higher, the coating material contains a polyol compound, a polyisocyanate compound, a heat resistance-imparting powder, and a water absorbent, the mixing ratio of the polyol compound and the polyisocyanate compound is 1.2 to 3.5 in terms of the NCO / OH equivalent ratio, The heat resistance-imparting powder contains a foaming agent, a charring agent, a flame retardant, and a filler, and contains 10 to 200 parts by weight of a foaming agent, 10 to 200 parts by weight of a charring agent, 30 to 800 parts by weight of a flame retardant, and 3 to 200 parts by weight of a filler with respect to 100 parts by weight of the solid content of the polyol compound, The water absorbent contains 5 to 50 parts by weight based on 100 parts by weight of the solid content of the polyol compound. The coating material is applied by applying one or several layers under high humidity conditions of 70% Rh or more of humidity, A film forming method characterized in that the dry film thickness per layer is 300 μm or more. 2. The film forming method according to claim 1, characterized in that the coating material has a main agent containing a polyol compound, a heat resistance-imparting powder, and a water absorbent, and a curing agent containing a polyisocyanate compound. 3. The above foaming agent contains one or more selected from melamine and its derivatives, dicyandiamide and its derivatives, azobistetrazole and its derivatives, azodicarbonamide, urea, and thiourea, The above charring agent contains one or more selected from pentaerythritol, dipentaerythritol, trimethylolpropane, starch, casein, and tris(2-hydroxyethyl)isocyanurate, The above flame retardant contains one or more selected from phosphorus trichloride, phosphorus pentachloride, ammonium phosphate, ammonium polyphosphate, melamine phosphate, melamine polyphosphate, melem polyphosphate, melam polyphosphate, boron phosphate, boron polyphosphate, aluminum phosphate, and aluminum polyphosphate, The above filler contains one or more selected from talc, calcium carbonate, sodium carbonate, aluminum oxide, titanium oxide, zinc oxide, silica, clay, clay, shirasu, mica, silica sand, silica stone powder, quartz powder, and barium sulfate, The film forming method according to claim 1, characterized by this.

Effects of the Invention

[0008] The present invention relates to a coating material whose film forms a carbonized heat-insulating layer due to a temperature rise. The coating material contains a polyol compound, a polyisocyanate compound, a heat resistance-imparting powder, and a water absorbent. The mixing ratio of the polyol compound and the polyisocyanate compound is 1 or more in terms of the NCO / OH equivalent ratio, so that the curability (curing rate, film hardness, etc.) of the film is excellent regardless of the coating environment, and the film performance can be stably ensured. Further, when the temperature rises due to a fire or the like, it has excellent foaming properties, suppresses the ashing and shrinkage of the carbonized heat-insulating layer, forms a stable carbonized heat-insulating layer, and can enhance the heat resistance protection of the base material.

Embodiments for Carrying Out the Invention

[0009] Hereinafter, the present invention will be described in detail based on its embodiments.

[0010] (Coating Material) The coating material of the present invention is one whose film forms a carbonized heat-insulating layer due to a temperature rise (heating) such as a fire, and is characterized by containing a polyol compound, a polyisocyanate compound, a heat resistance-imparting powder, and a water absorbent. Specifically, the film formed by the coating material of the present invention has excellent foaming properties when the temperature rises to 200 °C or higher (more preferably 250 °C or higher), and can enhance the heat resistance protection performance of the base material by forming a carbonized heat-insulating layer.

[0011] The coating material of the present invention contains a polyol compound (A1) and a polyisocyanate compound (A2) as essential components as the film-forming component (A). The polyol compound (A1) and the polyisocyanate compound (A2) are components that react to form a film.

[0012] In the present invention, as the polyol compound (A1), it is preferable to include a 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, still more preferably 5000 or more and 18000 or less, particularly preferably 6000 or more and 15000 or less, most preferably 6500 or more and 12000 or less). By including such a polyether polyol (a1) as the polyol compound (A1), excellent foaming properties are exhibited due to the temperature rise of the coating (preferably the coating surface temperature is 200 °C or more, more preferably 250 °C or more), and the heat-resistant protection performance of the substrate can be enhanced. In the present invention, the molecular weight of the polyol compound (A1) is the number average molecular weight (Mn), which is the so-called polystyrene-equivalent molecular weight determined by gel permeation chromatography using a polystyrene polymer as a reference.

[0013] The above polyether polyol (a1) is obtained, for example, by the addition polymerization of polyhydric alcohols such as trimethylolpropane, glycerin, hexanetriol, pentaerythritol derivatives, sorbitol, neopentyl glycol, etc. with alkylene oxides such as ethylene oxide and propylene oxide. In the present invention, polymers obtained by the addition polymerization of the above polyhydric alcohols with ethylene oxide and / or propylene oxide are suitable, and those with ethylene oxide and / or propylene oxide added to the ends are more suitable. Furthermore, as the above polyether polyol, it is preferable to include a polyether polyol having three or more functional groups having active hydrogen atoms (functional group number 3 or more). In this case, the curability is excellent and a stable coating can be formed, so the effects of the present invention are easily obtained. As the functional group having an active hydrogen atom, a hydroxyl group is suitable.

[0014] As such a polyether polyol (a1), the hydroxyl value (solid content) is preferably 3 to 150 mgKOH / g (more preferably 5 to 100 mgKOH / g, still more preferably 7 to 40 mgKOH / g, and most preferably 10 to 30 mgKOH / g). By using such a polyol compound (a1), more excellent foamability can be exhibited, and the heat-resistant protection performance of the base material can be enhanced. In the present invention, the hydroxyl value is a value (mgKOH / g) represented by the number of mg of potassium hydroxide equimolar to the hydroxyl groups contained in 1 g of the solid content, and "α to β" is synonymous with "α or more and β or less".

[0015] Moreover, the content of the above polyether polyol (a1) is preferably 50% by weight or more and 100% by weight or less (more preferably 60 to 99% by weight, still more preferably 70 to 98% by weight) based on the total amount of the polyol compound (A1).

[0016] In the present invention, it is preferable that the polyol compound (A1) contains a fluorine-containing polyol (a2). Thereby, due to the temperature rise of the coating film (preferably the coating film surface temperature is 200 °C or higher, more preferably 250 °C or higher), it has excellent foamability, suppresses the ashing and shrinkage of the carbonized heat-insulating layer, forms a stable carbonized heat-insulating layer, and can enhance the heat-resistant protection of the base material.

[0017] Such fluorine-containing polyol (a2) is not particularly limited. For example, it can be obtained by copolymerizing a fluorine-containing monomer such as a fluoroolefin monomer, a fluorine-containing alkyl group-containing acrylic monomer, etc., a hydroxyl group-containing vinyl monomer, and, if necessary, other polymerizable monomers. Examples of the fluoroolefin monomer include perfluoroolefins such as tetrafluoroethylene, chlorotrifluoroethylene, and hexafluoropropylene, vinyl fluoride, vinylidene fluoride, etc. Examples of the fluorine-containing alkyl group-containing acrylic monomer include perfluoromethyl methacrylate, perfluoroisononyl methyl methacrylate, 2-perfluorooctylethyl acrylate, 2-perfluorooctylethyl methacrylate, trifluoroethyl acrylate, etc. These can be used alone or in combination of two or more. In the present invention, it is preferably at least one selected from tetrafluoroethylene and chlorotrifluoroethylene, more preferably chlorotrifluoroethylene.

[0018] Examples of the hydroxyl group-containing vinyl monomer 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; 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.

[0019] Examples of other polymerizable monomers include alkyl (meth)acrylates 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, cyclohexyl (meth)acrylate; amino group-containing monomers such as dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, dimethylamino (meth)acrylate, aminoethyl (meth)acrylate, diethylaminoethyl (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, fumaric acid or its monoalkyl ester; amide-containing monomers such as (meth)acrylamide, 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, vinyltoluene; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate; olefinic monomers such as ethylene, propylene, etc. One or more of these can be used as necessary.

[0020] As such a fluorine-containing polyol (a2), it is preferable that the fluorine content in the solid content of the fluorine-containing polyol (a2) is 10 to 50% by weight (more preferably 15 to 40% by weight, still more preferably 20 to 35% by weight). Further, the hydroxyl value (solid content) is preferably 5 to 100 mgKOH / g (more preferably 10 to 80 mgKOH / g). Furthermore, the molecular weight [number average molecular weight (Mn)] is preferably 5000 to 100000 (more preferably 8000 to 60000). By including such a fluorine-containing polyol (a2), when the temperature rises due to a fire or the like, the coating film exhibits excellent foamability to form a carbonized heat-insulating layer, and it is possible to suppress ashing and shrinkage even in a high-temperature atmosphere, and the heat-resistant protection performance of the base material can be enhanced.

[0021] The content of the fluorine-containing polyol (a2) is preferably 0.1 to 30% by weight (more preferably 0.5 to 20% by weight, still more preferably 1 to 10% by weight) in terms of solid content based on the total amount of the polyol compound (A1). By satisfying this range, the heat-resistant protection performance of the base material can be enhanced, and sufficient adhesion to the topcoat material can be ensured.

[0022] Examples of the polyol compound (A1) of the present invention include, in addition to the above components (a1) and (a2), for example, polyester polyol, acrylic polyol, epoxy-containing polyol, silicone-containing polyol, castor oil, castor oil-modified polyol, polycarbonate polyol, polylactone polyol, polybutadiene polyol, polypentadiene polyol, etc., and one or more selected from these can be used.

[0023] The above polyol compound (A1) is preferably liquid at 20°C, and each viscosity is preferably 0.05 to 10 Pa·s (more preferably 0.1 to 5.0 Pa·s). Thereby, the effects of the present invention are easily obtained. The viscosity of the polyol component is the viscosity (pointer value at the 5th rotation) at 20 rpm measured with a BH type viscometer at a temperature of 20°C.

[0024] 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 obtained by allophanatization, biuretization, dimerization (uretdione formation), trimerization (isocyanurate formation), adduct formation, carbodiimidization, etc. of these; and blocked isocyanates obtained by blocking these with alcohols, phenols, ε-caprolactam, oximes, active methylene compounds, etc. One or more selected from these can be used.

[0025] 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 above 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). Also, an embodiment in which the polyisocyanate compound (A2) consists only of HMDIs is also suitable. Further, as the derivative, a biuret form and / or an isocyanurate form is suitable. In such a case, the curability of the formed film is excellent, and when the temperature rises, more excellent foaming properties can be exhibited, and the heat resistance protection of the substrate can be enhanced.

[0026] In the present invention, the polyisocyanate compound (A2) preferably contains an isocyanate group content in the solid content of 10% by weight or more (preferably 15% by weight or more and 30% by weight or less). In such a case, the effect of excellent curability of the formed film can be exhibited, and a stable film can be formed. In the present invention, the isocyanate group content is defined as the content (% by weight) of the isocyanate group contained in the solid content of the polyisocyanate compound, and is a value obtained by back-titration with hydrochloric acid after neutralizing the isocyanate group with an excessive amine.

[0027] In the present invention, the mixing ratio of the polyol compound (A1) and the polyisocyanate compound (A2) is characterized in that the NCO / OH equivalent ratio is 1 or more (preferably 1.2 to 3.5, more preferably 1.5 to 3.0). In such a case, regardless of the painting environment, it has excellent curability and can form a uniform film with a desired thickness. Further, when the coating material is overcoated, it has excellent interlayer adhesion and can stably form a thick film. Furthermore, the formed film has more excellent foaming properties against temperature rise due to a fire or the like, can form a stable carbonized heat insulating layer, and can enhance the heat resistant protection performance of the base material. Moreover, the formed film is excellent in durability (for example, waterproofness, water permeability resistance, crack resistance, substrate followability, etc.), can maintain the initial appearance (aesthetic appearance) over a long period of time, and can sufficiently exhibit the effects of the present invention against temperature rise due to a fire or the like.

[0028] In the present invention, a curing catalyst that promotes the reaction between the polyol compound (A1) and the polyisocyanate compound (A2) can be used in combination. A curing catalyst is a substance that has the effect of promoting the reaction of isocyanate groups to cause curing. Examples of curing catalysts include various types such as amine-based catalysts, organometallic-based catalysts, and inorganic-based catalysts. For example, examples of amine-based catalysts include ethylenediamine, triethylenediamine, triethylamine, ethanolamine, diethanolamine, and hexamethylenediamine or mixtures thereof with their derivatives or solvents. Examples of organometallic-based catalysts include organometallic compounds such as dibutyltin dilaurate and dibutyltin diacetate; and organometallic salts such as potassium acetate, zinc stearate, calcium stearate, lead stearate, aluminum stearate, and tin octylate. Examples of inorganic-based catalysts include tin chloride. These can be used alone or in combination of two or more, and can also be used after being mixed with a solvent. In the present invention, it is particularly preferable to contain an organometallic-based catalyst. In this case, it is possible to promote curing and enhance the curability of the film-forming component (A), thereby enhancing the effects of the present invention. The content of the curing catalyst is preferably 0.01 to 3 parts by weight (more preferably 0.05 to 2.5 parts by weight) based on 100 parts by weight of the solid content of the polyol compound (A1).

[0029] The cured film formed from the above film-forming component (A) preferably has an exothermic peak in differential thermal analysis (DTA method), and the exothermic peak preferably has a maximum value in the temperature range of 200 to 400 °C (more preferably 250 to 380 °C). In such a case, when the temperature rises due to a fire or the like, the foaming property is further improved, and it is possible to form an excellent carbonized heat-insulating layer, thereby enhancing the heat-resistant protection of the substrate.

[0030] The mechanism of action is not limited, but for example, the cured film of the film-forming component (A) begins to soften as the temperature rises, and then, decomposition reactions such as urethane bonds proceed. When the heat generation peak of the cured film of the film-forming component (A) has a maximum value within the above temperature range, foaming and carbonization reactions can proceed efficiently in a state where the film softens without much decomposition, so the foamability is improved, and furthermore, it is considered that a carbonized heat-insulating layer can be stably formed. In particular, in the present invention, since the film-forming component (A) contains a fluorine-containing polyol (a2) as the polyol compound (A), the heat generation peak of the cured film can be shifted to the high-temperature side. Thereby, the flame retardancy of the cured film can be enhanced, decomposition below 200°C can be suppressed, and it is considered that the effects of the present invention can be sufficiently exhibited.

[0031] In the present invention, the differential thermal analysis method of the cured film of the film-forming component (A) is measured using a cured film containing the above polyol compound (A1) and polyisocyanate compound (A2) as a sample. The differential thermal analysis method is measured using a differential thermal analyzer (for example, "Differential Thermal Balance Thermo plus EVO2 TG-DTA series" manufactured by Rigaku Corporation, etc.). 3±1 mg of the sample is taken in a platinum sample pan, α-alumina is used as the standard substance, and the temperature is changed from 100 to 900°C at a heating rate of 20°C / min for measurement.

[0032] In the coating material of the present invention, the heat resistance-imparting powder (B) is a component that forms a carbonized heat-insulating layer by its interaction with the above film-forming component (A) (for example, at least one of a dehydration cooling effect, a non-combustible gas generation effect, a carbonization promotion effect, a carbonized heat-insulating layer formation effect, etc.) due to a temperature rise during a fire or the like. As the heat resistance-imparting powder (B), it is preferable to contain one or more selected from, for example, a foaming agent (b1), a carbonizing agent (b2), a flame retardant (b3), and a filler (b4).

[0033] The foaming agent (b1) imparts a foaming effect to the coating due to the temperature rise during a fire or the like. Specifically, it imparts a foaming effect when the temperature on the surface of the coating 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, thiourea, and the like. 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) based on 100 parts by weight of the solid content of the polyol compound (A1).

[0034] The charring agent (b2) imparts the effect of forming a charred heat-insulating layer by charring and dehydrating and charring the above-mentioned film-forming component (A) due to the temperature rise during a fire or the like. Examples of the charring agent (b2) include pentaerythritol, dipentaerythritol, trimethylolpropane, starch, casein, tris(2-hydroxyethyl)isocyanurate, and the like. These can be used alone or in combination of two or more. In the present invention, pentaerythritol and dipentaerythritol are particularly preferable in terms of their excellent dehydration cooling effect and charred heat-insulating layer forming action. The content of the charring agent (b2) is preferably 10 to 200 parts by weight (more preferably 20 to 120 parts by weight) based on 100 parts by weight of the solid content of the polyol compound (A1).

[0035] 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 other 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, as the flame retardant (b3), for example, it preferably contains at least one phosphorus compound selected from melamine polyphosphate, melam polyphosphate, melamine·melam·melem double salt, or a composite compound of melamine·melam·melem double salt and dimelamine pyrosulfate. Furthermore, it is also preferable to contain ammonium polyphosphate in combination with these. The content of the flame retardant (b3) is preferably 30 to 800 parts by weight (more preferably 50 to 500 parts by weight) based on 100 parts by weight of the solid content of the polyol compound (A1).

[0036] Examples of the filler (b4) include talc, calcium carbonate, sodium carbonate, aluminum oxide, titanium oxide, zinc oxide, silica, clay, clay, shirasu, mica, silica sand, silica stone powder, quartz powder, and barium sulfate. These can be used alone or in combination of two or more. The content of the filler (b4) is preferably 3 to 200 parts by weight (more preferably 5 to 150 parts by weight) based on 100 parts by weight of the solid content of the polyol compound (A1).

[0037] Furthermore, in the present invention, in addition to the above components, a metal hydrate (b5), a fiber (b6), etc. can also be included. The metal hydrate (b5) exhibits endothermic properties due to dehydration reactions, etc. when the temperature rises, and is different from the above filler (b4). Examples of such metal hydrates (b5) include aluminum hydroxide, magnesium hydroxide, etc. These can be used alone or in combination of two or more. Also, 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) with respect to 100 parts by weight of the solid content of the above polyol compound (A1).

[0038] 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, even more preferably 0.5 to 10% by weight) with respect to the filler (b4). In this case, since the foaming property, particularly the shrinkage of the carbonized heat-insulating layer at high temperatures, etc. can be suppressed and a stable carbonized heat-insulating layer can be formed, the effects of the present invention can be enhanced. The average particle size is measured by a laser diffraction particle size distribution measuring device.

[0039] The fiber (b6) can enhance the thick coating property and suppress the cracking of the coating film. Also, when the temperature rises due to a fire or the like, the fiber (b6) can make it difficult for the coating film to sag and the like, and can enhance the thermal conductivity inside the coating film. As a result, it exhibits excellent foaming properties, forms a uniform carbonized heat-insulating layer, and can enhance the heat-resistant protection performance of the base material. Examples of such a fiber (b6) include organic fibers such as acrylic fiber, acetate fiber, aramid fiber, cuprammonium fiber (cupra), nylon fiber, novoloid fiber, pulp fiber, viscose rayon, vinylidene fiber, polyester fiber, polyethylene fiber, polyvinyl chloride fiber, polyvinylidene chloride fiber, polyacrylonitrile fiber, polypropylene fiber, and cellulose fiber, and inorganic fibers such as carbon fiber, rock wool fiber, glass fiber, silica fiber, alumina fiber, silica-alumina fiber, slag wool fiber, ceramic fiber, carbon fiber, and silicon carbide fiber. These can be used alone or in combination of two or more.

[0040] In the present invention, it is preferable that the fiber (b6) contains inorganic fibers. Among them, artificial mineral fibers such as rock wool fiber, slag wool fiber, glass fiber, and ceramic fiber are preferable. Thereby, the cracking of the coating film can be further suppressed. Furthermore, when the temperature rises due to a fire or the like, it can make it difficult for the coating film to sag and the like, and can further enhance the thermal conductivity inside the coating film. As a result, it exhibits excellent foaming properties uniformly up to the inside (core part) of the coating film, forms a more uniform and excellent-strength carbonized heat-insulating layer, and can further enhance the heat-resistant protection performance of the base material.

[0041] Also, the size (fiber length and fiber diameter) of the fiber (b6) may be set according to the performance of the coating material, the specification of the substrate to be applied, the coating tool, etc. The average fiber length is preferably 10 to 1000 μm (more preferably 15 to 800 μm, still more preferably 20 to 600 μm), and the average fiber diameter is preferably in the range of 0.5 to 10 μm (more preferably 1 to 8 μm). Also, its aspect ratio (fiber length / fiber diameter) is preferably 3 to 300 (more preferably 5 to 200). When the above range is satisfied, the thick coating property is enhanced, cracks in the formed film are less likely to occur, and when the temperature rises due to a fire or the like, sagging of the film is less likely to occur, and a stable carbonized heat insulation layer can be formed. The content of the fiber (b6) is preferably 0.5 to 30 parts by weight (more preferably 1 to 25 parts by weight, still more preferably 2 to 20 parts by weight) with respect to 100 parts by weight of the solid content of the above polyol compound (A1).

[0042] The coating material of the present invention is characterized by containing a water absorbent (C). The water absorbent (C) imparts the action of adsorbing moisture in the coating material and / or in the air. Moisture in the coating material and / or in the air easily reacts with the above polyisocyanate compound (A2). Therefore, in the coating method and coating environment of the coating material, particularly when the coating material is spray-coated or when coating (film formation) is performed under high humidity (furthermore, on rainy days or under high temperature and high humidity), it is easily affected by moisture in the air, and the reaction between the polyisocyanate compound (A2) and the polyol compound (A1) is inhibited, resulting in a decrease in curability (curing rate, film strength, etc.) and adhesion to the substrate, and as a result, sufficient heat resistance protection may not be obtained. In the present invention, by blending the water absorbent (C), by adsorbing moisture in the coating material or in the air, curability and adhesion to the substrate can be sufficiently ensured regardless of the coating method and coating environment, and a thick film can be stably formed.

[0043] The water absorbent (C) is not particularly limited as long as it exhibits the above effects. For example, a water binder (c1), a dehydrating agent (c2), etc. can be used. These can be used alone or in combination of two or more. Also, as the form of the water absorbent (C), any form such as pellet form, powder form, liquid form, paste form, etc. can be used. In the present invention, pellet form and powder form are preferred.

[0044] The above water binder (c1) has the effect of removing water in the coating material and / or in the air by reacting with water. Examples of such water binders include alkyl orthoformates such as methyl orthoformate, ethyl orthoformate, trimethyl orthoformate, triethyl orthoformate, tributyl orthoformate; trialkyl orthoacetates such as trimethyl orthoacetate, triethyl orthoacetate, tributyl orthoacetate; trialkyl orthoborates such as trimethyl orthoborate, triethyl orthoborate, tributyl orthoborate; monoisocyanate compounds such as phenyl isocyanate, p-chlorophenyl isocyanate, benzenesulfonyl isocyanate, p-toluenesulfonyl isocyanate, isocyanate ethyl methacrylate; alkoxysilanes such as tetraethoxysilane, tetrabutoxysilane, tetraphenoxysilane, tetrakis(2-ethoxybutoxy)silane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, trimethylethoxysilane, diphenyldiethoxysilane; acid anhydrides such as maleic anhydride, phthalic anhydride, etc.

[0045] The dehydrating agent (c2) has the function of removing water in the coating material and / or in the air by taking in water as crystal water, adsorbed water, etc. (water adsorbing property). Furthermore, since the dehydrating agent can dehydrate the adsorbed water when the temperature rises (at high temperature), the heat-resistant protection property can be enhanced. Examples of such dehydrating agents include silica gel, synthetic zeolite, natural zeolite, synthetic clay, activated alumina, calcium oxide, magnesium sulfate, sodium sulfate, hemihydrate gypsum, anhydrous gypsum, crystalline gypsum, cement, activated carbon, partially crosslinked acrylic acid polymer (superabsorbent polymer), and the like.

[0046] In the present invention, the above dehydrating agent (c2) is preferred as the water absorbent (C). Among them, porous inorganic particles such as silica gel, synthetic zeolite, natural zeolite, and activated alumina are preferred, and in terms of their form, a powder form is suitable. In the present invention, in particular, powdered synthetic zeolite is preferred. Examples of the types of synthetic zeolite include A-type, X-type, Y-type, L-type, mordenite-type, and chabazite-type, and A-type zeolite is suitable in the present invention. Also, the average pore diameter of the porous inorganic particles may be larger than the molecular diameter of water molecules (about 2.3 to 3.9 Å), preferably 2.3 to 30 Å (more preferably 2.5 to 10 Å, still more preferably 3 to 8 Å, particularly preferably 3.5 to 5 Å). In this case, it has excellent water adsorbing property, excellent curability of the above component (A), and can increase the curing rate and film hardness. Also, it has excellent adhesion to the substrate, can form a uniform film, and when the temperature rises due to a fire or the like, it can sufficiently exhibit the effect of maintaining the heat-resistant protection performance of the substrate without inhibiting the foaming property of the film (without adsorbing non-combustible gas, etc.). The average pore diameter of the porous inorganic particles can be measured, for example, by nitrogen adsorption measurement.

[0047] When the water absorbent (C) is in powder form, its average particle diameter is preferably 30 to 500 μm (more preferably 40 to 400 μm, still more preferably 50 to 300 μm).

[0048] The content of the water absorbent (C) is preferably 0.5 to 50 parts by weight (more preferably 1 to 50 parts by weight, still more preferably 1.5 to 30 parts by weight) with respect to 100 parts by weight of the solid content of the above polyol compound (A1).

[0049] The coating material of the present invention preferably further contains a high-boiling compound (D). The high-boiling compound (D) is a high-boiling liquid compound that is liquid at 20°C and has a boiling point of 100°C or higher (more preferably 150°C or higher, still more preferably 200°C or higher). By containing such a high-boiling compound (D), the dispersion stability of the heat resistance-imparting component (B) and the like can be enhanced. In addition, a good film excellent in adhesion can be formed, particularly the elasticity of the film is improved and cracks in the film can be prevented. Furthermore, when the film is exposed to high temperatures due to a fire or the like, it contributes to appropriate softening of the film and further enhances the foaming property, suppresses the peeling (peeling off) of the formed carbonized heat-insulating layer, and can enhance the heat resistance protection performance of the base material.

[0050] The high-boiling compound (D) is not particularly limited as long as it satisfies the above conditions. For example, phthalic acid ester compounds such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, dihexyl phthalate, di-2-ethylhexyl phthalate, diisononyl phthalate, diisodecyl phthalate, diundecyl phthalate, butyl benzyl phthalate; aliphatic dibasic acid ester compounds such as 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, dihexyl sebacate, di-2-ethylhexyl sebacate; adipic acid-based polyesters such as adipic acid-1,3-butylene glycol-based polyester, adipic acid-1,2-propylene glycol-based polyester; maleic acid ester compounds such as dimethyl maleate, diethyl maleate, dibutyl maleate, dihexyl maleate, di-2-ethylhexyl maleate, diisononyl maleate, diisodecyl maleate; phosphate ester compounds such as triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate;

[0051] trimellitic acid ester compounds such as tris-2-ethylhexyl trimellitate; ricinoleic acid ester compounds such as methyl acetyl ricinoleate; epoxy-based ester compounds such as epoxyhexahydrophthalic acid di-2-ethylhexyl, epoxyhexahydrophthalic acid diepoxystearyl, epoxidized fatty acid butyl, epoxidized fatty acid 2-ethylhexyl, epoxidized soybean oil, epoxidized linseed oil; benzoic acid ester compounds such as benzoic acid glycol ester; aromatic hydrocarbon compounds such as 1-phenyl-1-xylylethane, 1-phenyl-1-ethylphenyl ethane; lactones such as γ-butyrolactone; mixtures of petroleum resins (aromatic hydrocarbon fraction polymers having 8 to 10 carbon atoms) and styryl xylene, etc. These can be used alone or in combination of two or more.

[0052] In the present invention, the high-boiling compound (D) preferably contains one or more selected from phthalic acid ester compounds, aliphatic dibasic acid ester compounds, and phosphoric acid ester compounds. More preferably, it contains one or more selected from phthalic acid ester compounds and aliphatic dibasic acid ester compounds in which the alkyl group has 4 to 11 carbon atoms (more preferably 5 to 10 carbon atoms, and even more preferably 6 to 9 carbon atoms). Specific examples thereof include, for example, diisononyl phthalate, diisononyl adipate, etc., which are suitable.

[0053] The content of the high-boiling compound (D) 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) with respect to 100 parts by weight of the solid content of the above polyol compound (A1). When the above range is satisfied, the dispersibility of the above powder component is enhanced, the thick coating property is excellent, and when the temperature rises due to a fire or the like, it has excellent foaming properties and can sufficiently exhibit the effect of maintaining the heat-resistant protection performance of the base material. Furthermore, excellent overcoating material suitability can be obtained.

[0054] In addition, as the additive, any one that does not significantly inhibit the effects of the present invention may be used. For example, pigments, wetting agents, plasticizers, lubricants, preservatives, antifungal agents, algicides, antibacterial agents, thickeners, leveling agents, dispersants, defoamers, crosslinking agents, silane coupling agents, ultraviolet absorbers, light stabilizers, antioxidants, halogen scavengers, diluting solvents, etc. can be mentioned.

[0055] Among these, examples of the antioxidant include phosphorus-based, sulfur-based, or hindered phenolic antioxidants, etc. These can be used alone or in combination of two or more. By including such an antioxidant, not only during normal times but also when the temperature rises due to a fire or the like, the deterioration of the coating film can be suppressed, and the properties of the carbonized heat-insulating layer formed by the temperature rise can be improved.

[0056] The coating material of the present invention preferably has a heat residue of 70 to 98% by weight (more preferably 75 to 95% by weight, still more preferably 80 to 93% by weight). When the heat residue of the coating material satisfies the above range, it has excellent thick coating property and can obtain good coating workability. Thereby, sufficient heat resistance protection can be exhibited. The heat residue of the coating material is a value measured by the method of JIS K 5601-1-2, the heating temperature is 105 ° C, and the heating time is 60 minutes).

[0057] Further, in the present invention, the viscosity of the coating material is preferably 5 to 70 Pa·s (more preferably 7 to 60 Pa·s, still more preferably 10 to 50 Pa·s, particularly preferably 15 to 40 Pa·s). When the viscosity of the coating material satisfies the above range, it has excellent coating workability and thick coating property, and a uniform film can be formed. As a result, sufficient heat resistance protection can be obtained. The viscosity of the coating material is the viscosity (pointer value at the 5th rotation) at 20 rpm measured with a BH type viscometer at a temperature of 23 ° C immediately after the coating material is prepared (in the case of a two-component type, after the main agent and the curing agent are mixed).

[0058] In the present invention, by applying a coating material that satisfies the above heat residue and the above viscosity range to form a film, the film can be thickened, and good adhesion to the substrate can be shown, and a uniform film can be stably formed. Furthermore, the formed film exhibits excellent foaming properties when the temperature rises due to a fire or the like, forms a carbonized heat insulating layer, and can maintain the heat resistance protection performance of the substrate.

[0059] The coating material of the present invention is preferably a two-component type coating material having a main agent containing the above polyol compound (A1) and a curing agent containing the above polyisocyanate compound (A2). That is, during distribution, the main agent and the curing agent are stored in separate packages, and they may be mixed during use (coating). In this case, the heat resistance-imparting powder (B), the water absorbent (C), (optionally the high-boiling compound (D), the curing catalyst, the additive) may be mixed with at least one of the main agent and the curing agent, but in the present invention, it is preferably mixed with the main agent. Also, each component can be added when the main agent and the curing agent are mixed.

[0060] The coating material of the present invention is suitable as an expandable fireproof coating material for applying to the surface coating of structures such as buildings and civil engineering structures. Specifically, it can be applied to various base materials such as walls, columns, floors, beams, roofs, stairs, ceilings, and doors. Examples of applicable base materials include concrete, mortar, siding board, extruded board, gypsum board, perlite board, brick, plastic, wood, metal, steel frame (steel material), glass, porcelain tile, etc. These base materials may have a film already formed on their surface, have been subjected to some base treatment (rust prevention treatment, flame retardant treatment, etc.), or have wallpaper pasted on them, etc.

[0061] When applying the coating material of the present invention to a base material, for example, coating tools such as spray, roller, brush, and trowel can be used. Among them, the coating material of the present invention is particularly suitable for spray painting because it can suppress the reaction between moisture in the air and the polyisocyanate compound (A2) during painting.

[0062] (Film formation method) The film formation method of the present invention is to form a film by applying the above coating material to a base material. The coating method is not particularly limited, and for example, it can be applied using various methods such as brush coating, roller coating, spray coating (air spray, airless spray), etc.

[0063] The coating material of the present invention is also suitable for spray coating (air spray, airless spray). Since the coating material of the present invention contains the water absorbent (C) and can suppress the reaction between moisture in the air and the polyisocyanate compound (A2), even when the coating material is atomized during spray coating, good curability can be ensured and a thick film can be efficiently formed. Further, the coating material can be applied at an air temperature of -10 to 45°C, and particularly good coating workability and curability can be obtained even at a high temperature of 30°C or higher (more preferably 35°C or higher). Furthermore, the humidity during coating is not particularly limited, but good coating workability, curability, and adhesion to the substrate can be obtained even under high humidity conditions of 70% Rh or higher (more preferably 80% Rh or higher) (including rainy days). As a result, a film excellent in heat protection can be formed. Also, even when the curing (drying) environment of the coating material after coating is under high humidity, excellent curability and adhesion to the substrate can be obtained, and a film excellent in heat protection can be formed.

[0064] When applying the coating material of the present invention to a substrate, it may be applied by coating one or several steps by the above method, but it is preferably applied so that the dry film thickness per step is preferably 300 μm or more (more preferably 400 to 8000 μm). Even when the coating material of the present invention is applied so that the dry film thickness per step exceeds 1000 μm, excellent curability and adhesion to the substrate can be obtained, and a film excellent in heat protection can be formed. Also, the film thickness of the finally formed film may be appropriately set according to the desired functionality, application site, etc., but is preferably about 0.4 to 8 mm. Further, since the coating material of the present invention forms a film by the reaction of the polyol compound (A1) and the polyisocyanate compound (A2) in the presence of the above component (C), it has excellent curability, and its drying is preferably at room temperature, and the interval to the next step is preferably 2 hours or more (more preferably 3 hours or more and within 30 days).

[0065] (Primer) In addition, in the present invention, if necessary, before applying the above coating material, the base material can be surface-treated or an undercoat material can be applied. Thereby, the adhesion to the base material can be improved, and the corrosion resistance (rust prevention property) and the like can be enhanced. Examples of the surface treatment of the base material include surface treatment with a solvent, an acid, or the like, and chamfering with a disk sander, a wire wheel, a scraper, a wire brush, sandpaper, or the like.

[0066] Examples of the undercoat material include sealers, primers, substrate conditioners, surfacers, putties, etc. In addition, flat-type paints can also be applied. These can be either clear-type or colored-type. Also, they can be either water-based or solvent-based, and can be appropriately selected according to the painting location or the like, and one kind or two or more kinds can be used. As the undercoat material, it is preferably suitable to contain resin components such as acrylic resin, urethane resin, epoxy resin, etc. In addition to the above resin components, various additives can be blended to such an extent that they do not affect the effects of the present invention. Examples of such additives include rust-preventive pigments, extender pigments, coloring pigments, plasticizers, antiseptics, antifungal agents, algicides, defoamers, leveling agents, pigment dispersants, anti-settling agents, anti-dripping agents, antioxidants, catalysts, crosslinking agents, and the like.

[0067] The undercoat material can be applied using various methods such as brush painting, roller painting, spray painting, etc. The application amount is preferably 30 to 500 g / m 2 (more preferably 50 to 300 g / m 2 ). The number of coating times of the undercoat material can be appropriately set according to the surface state of the base material or the like, but is preferably 1 to 2 times.

[0068] (finishing material) The present invention can laminate a finishing material layer on the coating material layer (film) formed by the above coating material. As such a finishing material layer, as long as the coating material layer does not inhibit the formation of a carbonized heat insulation layer by foaming when the temperature rises due to a fire or the like, it is not particularly limited, and known finishing materials can be laminated. Such a finishing material layer can be laminated by applying a topcoat material or by attaching and laminating various sheet materials.

[0069] As the above topcoat material, any of a clear type or a colored type, a glossy type or a matte type, a hard type or an elastic type, a thin film type or a thick film type, etc. can be used. Also, it can be either water-based or solvent-based and can be appropriately selected according to the desired purpose. Further, the topcoat material of the present invention preferably contains a resin component. Examples of such resin forms include solvent-soluble resins, non-aqueous dispersion resins, solvent-free resins, water-dispersion resins, water-soluble resins, etc. Examples of resin types include acrylic resins, urethane resins, epoxy resins, vinyl chloride resins, vinyl acetate resins, acrylic silicone resins, fluorine resins, silicone resins, polyvinyl alcohol, cellulose derivatives, etc., or composites thereof, etc. These can be used singly or in combination of two or more. In the present invention, it is particularly preferable to contain one or more selected from urethane resins, epoxy resins, acrylic resins, and acrylic silicone resins.

[0070] Furthermore, the resin component may have crosslinking reactivity. When the resin component is a crosslinking reaction type resin, the water resistance, durability, and adhesion of the formed film are enhanced, and the occurrence of film swelling and peeling due to rainfall, dew condensation, etc., and the deterioration of heat resistance performance can be suppressed. Such a crosslinking reaction type resin may be one that causes a crosslinking reaction by itself or one that causes a crosslinking reaction by a separately mixed crosslinking agent. Such crosslinking reactivity can be imparted, for example, by combining reactive functional groups such as a hydroxyl group and an isocyanate group, a carbonyl group and a hydrazide group, an epoxy group and an amino group, an aldehyde group and a semicarbazide group, a keto group and a semicarbazide group, alkoxyl groups, a carboxyl group and a metal ion, a carboxyl group and a carbodiimide group, a carboxyl group and an epoxy group, a carboxyl group and an aziridine group, a carboxyl group and an oxazoline group. Among these, it is preferable to contain one or more crosslinking reaction type resins selected from a hydroxyl group - isocyanate group, a carbonyl group and a hydrazide group, and an epoxy group and an amino group.

[0071] As components other than the resin component of the topcoat material, for example, a coloring pigment, an extender pigment, an aggregate, etc. can be mixed. By appropriately blending such components, a desired color and texture can be exhibited. The mixing amount of the coloring pigment, extender pigment, aggregate, etc. is not particularly limited as long as it does not inhibit the effects (foaming property, heat protection property, etc.) of the coating material, but is preferably 1 to 2000 parts by weight (more preferably 5 to 1000 parts by weight) with respect to 100 parts by weight of the solid content of the resin component.

[0072] In particular, in the present invention, it is preferable to use a pigment having infrared reflectivity and / or infrared transmissivity as the coloring pigment and extender pigment. Thereby, the effects such as heat protection property can be further enhanced.

[0073] Examples of the infrared-reflective pigments include aluminum flakes, titanium oxide, barium sulfate, zinc oxide, iron oxide, calcium carbonate, silicon oxide, magnesium oxide, zirconium oxide, yttrium oxide, indium oxide, alumina, iron-chromium composite oxides, manganese-bismuth composite oxides, manganese-yttrium composite oxides, black iron oxide, iron-manganese composite oxides, iron-copper-manganese composite oxides, iron-chromium-cobalt composite oxides, copper-chromium composite oxides, copper-manganese-chromium composite oxides, etc., and one or more of these can be used.

[0074] Examples of the infrared-transmissive pigments include perylene pigments, azo pigments, lead yellow, titanium red, cadmium red, quinacridone red, isoindolinone, benzimidazolone, phthalocyanine green, phthalocyanine blue, cobalt blue, indanthrene blue, ultramarine blue, dark blue, etc., and one or more of these can be used.

[0075] Furthermore, various additives that can be normally used in paints can also be incorporated into the topcoat material. Examples of such additives include thickeners, film-forming aids, leveling agents, wetting agents, plasticizers, antifreezing agents, pH adjusters, antiseptics, antifungal agents, algicides, antibacterial agents, dispersants, defoamers, adsorbents, ultraviolet absorbers, light stabilizers, antioxidants, fibers, low-pollution agents, hydrophilizing agents, water-repellent agents, coupling agents, catalysts, etc.

[0076] In the film-forming method of the present invention, the topcoat material can be applied by overcoating or by laminating and applying two or more topcoat materials. When laminating two or more topcoat materials, as the first topcoat material (intermediate coat), it is preferable to contain one or more resin components selected from urethane resins, epoxy resins, acrylic resins, and acrylic-silicone resins (particularly preferably, urethane resins, epoxy resins, etc.). Thereby, the adhesion between the above coating material and the topcoat material layer can be further enhanced. Furthermore, a topcoat material film excellent in film physical properties can be formed.

[0077] The topcoat can be applied by known coating methods. For example, it can be applied using various methods such as brush painting, roller painting, spray painting, etc. The coating amount is preferably 30 - 5000 g / m 2 (more preferably 50 - 3000 g / m 2 ). The number of coats of the topcoat may be appropriately set according to the surface condition of the substrate, etc., but is preferably 1 - 2 coats. Also, drying is preferably carried out at room temperature.

[0078] Examples of the sheet material include a decorative film, a decorative sheet, a sheet building material, wallpaper, etc. Also, its thickness is preferably 0.01 - 30 mm (more preferably 0.05 - 20 mm). These may be adhered via a known adhesive (adhesive), etc.

Examples

[0079] Examples are shown below to clarify the features of the present invention. However, the present invention is not limited to this range.

[0080] The following were used as each raw material.

[0081] · Polyol compound (A1) (a1 - 1) Polyether polyol (number average molecular weight 7000, functionality 3, hydroxyl value 24 mgKOH / g) (a1 - 2) Polyether polyol (number average molecular weight 5100, functionality 3, hydroxyl value 33 mgKOH / g) (a1 - 3) Polyether polyol (number average molecular weight 4000, functionality 3, hydroxyl value 43 mgKOH / g) (a2) Fluorine - containing polyol (chlorotrifluoroethylene - vinyl ether - hydroxyalkyl vinyl ether copolymer, fluorine content 27% by weight, hydroxyl value (solid content) 52 mgKOH / g, solid content 60% by weight, containing aromatic hydrocarbon solvent)

[0082] · Polyisocyanate compound (A2) (A2) Biuret - type hexamethylene diisocyanate (NCO content 23.5%)

[0083] · Flame-retardant component (B) (b1) Blowing agent: Melamine (b2) Carbonizing agent: Pentaerythritol (b3-1) Flame retardant: Ammonium polyphosphate (b3-2) Flame retardant: Melamine polyphosphate·Melam·Melamem double salt (b4) Filler: Titanium oxide (b5) Metal hydrate: Aluminum hydroxide (average particle size: 1 μm) (b6) Fiber: Rock wool fiber (average fiber length 125 μm, average fiber diameter 4.5 μm) · Water absorbent (C) (C1) Powdered synthetic zeolite (average particle size 150 μm or less, A-type, average pore diameter 4 Å) (C2) Powdered synthetic zeolite (average particle size 150 μm or less, X-type, average pore diameter 9 Å) (C3) Synthetic silica gel (average particle size 40 μm, A-type, average pore diameter 24 Å) · High-boiling compound (D) (D1) Diisononyl phthalate (boiling point 420 °C) · Curing catalyst: Organometallic catalyst · Additive 1: Dispersant, defoamer, thickener, etc. · Additive 2: Diluting solvent, etc.

[0084] (Examples 1 to 14, Comparative Examples 1 to 3) <Manufacture of coating material> According to the formulation shown in Table 1, component (A1), component (B), component (C), component (D), and others (curing catalyst, additives 1 and 2) were mixed by a conventional method to prepare the main agent. Next, component (A2) (curing agent) was mixed so that the NCO / OH equivalent ratio shown in Table 1 was obtained to obtain the coating material.

[0085] <Preparation of test specimens> The coating material was sprayed onto the entire surface of a steel plate (150 mm long x 70 mm wide x 1.6 mm thick) that had previously been painted with an anti-rust coating, under the painting environment described below, so that the dry film thickness was 1.5 mm. After curing (process interval described below), the same coating material was sprayed onto the entire surface of the plate so that the dry film thickness was 1.5 mm, and the plate was then cured (24 hours, 7 days) to prepare the test specimen. ·Painting environment (painting and curing conditions) [1] Room temperature (25℃, 60%Rh, process interval 16 hours) [2] Under high temperature and high humidity (30℃, 90%Rh, process interval 16 hours) [3] Under high temperature and high humidity (30℃, 90%Rh, process interval 3 hours)

[0086] <Curing evaluation> (Coating hardness) The hardness of the coating was measured using an A-type durometer (rubber hardness tester, manufactured by Asker Corporation). The evaluation criteria are as follows: A:Hardness 80 or more B: Hardness over 70 and below 80 C: Hardness over 55 and below 70 D:Hardness 55 or less (Interlayer adhesion) After 7 days of curing, cross-cuts were made in the coating of the test specimen with a utility knife, and tape was applied to the cross-cut areas and then peeled off to evaluate adhesion. The evaluation criteria were a four-level evaluation (A>B>C>D: poor), with "A" being no abnormality and "D" being peeled off between layers. It is as follows.

[0087] <Heat resistance evaluation> A coating material was sprayed onto the entire surface of a steel plate (150 mm long x 70 mm wide x 1.6 mm thick) that had been previously coated with an anti-rust paint under application conditions [2] so that the dry film thickness was 1.5 mm, and after curing for 16 hours, the same coating material was sprayed onto the plate so that the dry film thickness was 1.5 mm, and after curing for 7 days, the plate was used as a test specimen and the following evaluations were carried out. The results are shown in Table 1. <Heat resistance evaluation> Based on the ISO 5660-1 cone calorimeter method, an electric heater (CONEIII, manufactured by Toyo Seiki Co., Ltd.) was used to apply 50 kW / m to the surface of the test specimen.2 The expansion ratio and the temperature of the back surface of the steel plate were measured when the radiant heat was radiated for 30 minutes, and furthermore, the airtightness and the ashing property were evaluated. Each evaluation criterion is as follows. (Expansion ratio) AA: Expansion ratio exceeds 35 times A: Expansion ratio exceeds 25 times and is 35 times or less B: Expansion ratio exceeds 20 times and is 25 times or less C: Expansion ratio exceeds 15 times and is 20 times or less D: Expansion ratio is 15 times or less (Temperature of the back surface) AA: Less than 430°C A: 430°C or more and less than 470°C B: 470°C or more and less than 500°C C: 500°C or more and less than 550°C D: More than 550°C (Airtightness evaluation) The test piece for which the expansion ratio was measured was cut, and the airtightness of the carbonized heat insulation layer in the cross section was visually confirmed. The evaluation criterion was a four-level evaluation (excellent: A > B > C > D: poor) where those with high airtightness were rated as "A" and those with low airtightness were rated as "D". (Ashing property evaluation) In the above heat resistance evaluation 2, the cross section of the carbonized heat insulation layer formed after radiating the radiant heat for 30 minutes was confirmed, and the ratio of the ashed (white) part was calculated. The evaluation criterion was a four-level evaluation (excellent: A > B > C > D: poor) where those with less ashing were rated as "A" and those with advanced ashing were rated as "D".

[0088]

Table 1

Claims

1. A coating forming method for forming a coating by applying a coating material to a substrate, comprising the steps of: The coating material is a coating material that forms a carbonized heat insulating layer when its coating is heated to 200° C. or higher, The coating material includes a polyol compound, a polyisocyanate compound, a heat resistance imparting powder, and a water absorbing agent, a mixing ratio of the polyol compound to the polyisocyanate compound is 1.2 to 3.5 in terms of NCO / OH equivalent ratio, The heat resistance imparting powder includes a foaming agent, a carbonizing agent, a flame retardant, and a filler, The composition contains 10 to 200 parts by weight of a foaming agent, 10 to 200 parts by weight of a carbonizing agent, 30 to 800 parts by weight of a flame retardant, and 3 to 200 parts by weight of a filler, relative to 100 parts by weight of a solid content of the polyol compound; The water absorbing agent is contained in an amount of 5 to 50 parts by weight based on 100 parts by weight of the solid content of the polyol compound, The coating material is applied in one or several steps under high humidity conditions of 70% Rh or more, The coating method is characterized in that the dry film thickness per step is 300 μm or more.

2. 2. The method for forming a coating film according to claim 1, wherein the coating material comprises a base agent containing a polyol compound, a heat resistance imparting powder, and a water absorbing agent, and a curing agent containing a polyisocyanate compound.

3. The foaming agent includes at least one selected from the group consisting of melamine and its derivatives, dicyandiamide and its derivatives, azobistetrazole and its derivatives, azodicarbonamide, urea, and thiourea; The carbonizing agent includes one or more selected from pentaerythritol, dipentaerythritol, trimethylolpropane, starch, casein, and tris(2-hydroxyethyl)isocyanurate; The flame retardant includes at least one selected from 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; The filler includes at least one selected from the group consisting of talc, calcium carbonate, sodium carbonate, aluminum oxide, titanium oxide, zinc oxide, silica, clay, siliceous sand, mica, silica sand, silica powder, quartz powder, and barium sulfate. The method for forming a coating according to claim 1 .

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