Covering material

Abstract

The present invention provides a thermally expandable coating material that can suppress incineration due to combustion of a carbonized heat insulating layer and maintain sufficient fire resistance. The present invention provides a thermally expandable coating material comprising a binder, a flame retardant, a foaming agent, and a carbonizing agent, The carbonizing agent is characterized by containing an alicyclic polyhydric alcohol.

Description

[Technical Field]

[0001] The present invention relates to a novel coating material. [Background technology]

[0002] Various thermally expandable coating materials have been proposed to protect substrates such as steel, concrete, wood, and synthetic resins from fire. These materials expand when exposed to temperatures such as during a fire, forming a carbonized insulating layer. Known examples of such coating materials include those containing a binder, a foaming agent, a carbonizing agent, a flame retardant, and the like.

[0003] Such coating materials exhibit heat insulation properties through a carbonized insulation layer (foam layer) that foams due to a temperature rise during a fire, etc., and it is important to improve the strength and shape retention of the carbonized insulation layer. For example, Patent Document 1 describes that the use of a resin component having a reactive silicon group makes it easier to maintain the shape of the carbonized insulation layer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-116551 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the carbonized insulation layer is exposed to fire for a long period of time or is located close to the source of the fire, the carbonized insulation layer may be burned to ashes, and may not be able to maintain sufficient fire resistance. [Means for solving the problem]

[0006] In order to solve these problems, the inventors discovered that by including a specific carbonizing agent in a thermally expandable coating material, it is possible to suppress incineration due to combustion of the carbonized insulation layer and maintain sufficient fire resistance, thereby completing the present invention.

[0007] That is, the present invention has the following features. 1. A thermally expandable coating material comprising a binder, a flame retardant, a foaming agent, and a charring agent, The coating material, wherein the carbonizing agent contains an alicyclic polyhydric alcohol. 2. The coating material according to 1, wherein the alicyclic polyhydric alcohol includes an alicyclic polyhydric alcohol having 6 to 20 carbon atoms. [Effects of the Invention]

[0008] The coating material of the present invention is a thermally expandable coating material containing a binder, a flame retardant, a foaming agent, and a carbonizing agent. The carbonizing agent contains an alicyclic polyhydric alcohol, which suppresses incineration due to combustion of the carbonized insulation layer and maintains sufficient fire resistance. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described.

[0010] The present invention relates to a thermally expandable coating material (e.g., intumescent fireproof paint, intumescent fireproof sheet, etc.) that contains a binder, a flame retardant, a foaming agent, and a carbonizing agent. This coating material foams in response to a temperature rise during a fire or other event, forming a carbonized insulating layer and enhancing the fire resistance of the substrate. The coating formed by the coating material of the present invention has excellent foaming properties at temperatures of 200°C or higher (more preferably 250°C or higher), and can increase the fire resistance of the substrate by forming a carbonized heat insulating layer.

[0011] The binder of the present invention can be one that is used in known thermally expandable coating materials. Such synthetic resins can be either thermoplastic or thermosetting resins, and known resins can be used. Examples of such resins include water-dispersible, water-soluble, NAD, solvent-soluble, solventless, and powdered resins (including beaded and pelleted forms), and can be used without particular limitation, such as one-component and two-component types. Specific examples of thermosetting resins include epoxy resins, urethane resins, fluororesins, alkyd resins, phenolic resins, and melamine resins. Examples of thermoplastic resins include polyester resins, polybutadiene resins, acrylic resins, styrene resins, acrylic-styrene resins, vinyl acetate resins, vinyl acetate / versatate vinyl ester copolymer resins, vinyl acetate / ethylene copolymer resins, vinyl acetate / versatate vinyl ester / acrylic copolymer resins, vinyl acetate / acrylic copolymer resins, polyethylene resins, vinyl chloride resins, polypropylene resins, and polystyrene resins. These resins can be used alone or in combination of two or more.

[0012] Flame retardants generally exhibit at least one of the following effects in the event of a fire: dehydration and cooling, non-flammable gas generation, and promoting carbonization of thermoplastic resins, thereby suppressing the combustion of resin components. The flame retardant used in the present invention is not particularly limited as long as it has such an effect, and known flame retardants can be used. Examples include phosphorus compounds, chlorine compounds, antimony compounds, and boron compounds. One or more of these compounds can be used in combination. Specific examples of suitable flame retardants include 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, aluminum polyphosphate, tricresyl phosphate, and diphenyl cresyl phosphate; chlorine compounds such as chlorinated polyphenyls, chlorinated polyethylene, diphenyl chloride, triphenyl chloride, chlorinated paraffins, pentachlorinated fatty acid esters, perchloropentacyclodecane, chlorinated naphthalene, and tetrachlorophthalic anhydride; antimony compounds such as antimony trioxide and antimony pentachloride; and boron compounds such as borax, zinc borate, and sodium borate. These compounds may be used alone or in combination. These compounds may be either uncoated or coated. In the present invention, a phosphorus compound is preferably included as the flame retardant.

[0013] The mixing ratio of the flame retardant is preferably 50 to 1000 parts by mass (more preferably 100 to 800 parts by mass, and even more preferably 150 to 600 parts by mass) relative to 100 parts by mass (solid content) of the binder. In the present invention, by including the flame retardant in such a relatively high ratio, good fire resistance can be obtained.

[0014] The foaming agent generally has the effect of generating a non-flammable gas in the event of a fire, foaming the carbonizing resin component and carbonizing agent, and forming a carbonized insulating layer having pores. The foaming agent is not particularly limited as long as it has this effect, and known foaming agents can be used. Examples include melamine and its derivatives, dicyandiamide and its derivatives, azodicarbonamide, urea, thiourea, etc., and one or more selected from these can be used. Among these, melamine, dicyandiamide, azodicarbonamide, etc. are preferably used.

[0015] The mixing ratio of the foaming agent is preferably 5 to 500 parts by mass (more preferably 10 to 200 parts by mass, and even more preferably 30 to 150 parts by mass) per 100 parts by mass (solid content) of the binder. By using the foaming agent in this range, excellent foaming properties can be exhibited, and good performance can be obtained in terms of heat insulation and fire resistance.

[0016] Carbonizing agents generally have the effect of forming a thick carbonized insulation layer with excellent thermal insulation properties by dehydrating and carbonizing themselves in the event of a fire while carbonizing the thermoplastic resin. The present invention is characterized in that the carbonizing agent contains an alicyclic polyhydric alcohol. This can suppress the carbonized insulation layer from burning to ashes, even when the carbonized insulation layer is exposed to fire for a long period of time or is close to the source of the fire. The mechanism of action is not limited, but the alicyclic polyhydric alcohol is a compound having at least one alicyclic ring and at least two hydroxyl groups per molecule, and the alicyclic ring is incorporated during the formation of the carbonized insulation layer. This improves the heat resistance and fire resistance of the carbonized insulation layer and suppresses the carbonized insulation layer from burning to ashes.

[0017] In the present invention, the alicyclic polyhydric alcohol is preferably an alicyclic polyhydric alcohol having 6 to 20 carbon atoms. Examples of such alicyclic polyhydric alcohols include 1,4-cyclohexanediol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, hydrogenated bisphenol F, glycols having a spiro ring, and dihydroxymethyltricyclodecane, and one or more selected from these can be used. Among these, glycols having a spiro ring are preferably used.

[0018] Examples of glycols having a spiro ring include: 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, 3,9-bis(2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, 3,9-bis(1-methyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, 3,9-bis(1-ethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, 3,9-bis(1-ethyl-1-methyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, 3,9-bis(2-hydroxyethyl-2-methyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, 3,9-bis(1-methyl-2-hydroxy-2-methylethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, 3,9-bis(1-ethyl-2-hydroxy-2-methylethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, 3,9-bis(1,1-dimethyl-2-hydroxy-2-methylethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, 3,9-bis(1-ethyl-1-methyl-2-hydroxy-2-methylethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, 3,9-bis(2-hydroxypropyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, etc., and one or more selected from these can be used. Among these, 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane is preferably used.

[0019] In the present invention, in addition to the alicyclic polyhydric alcohol, a known carbonizing agent can be used in combination as a carbonizing agent. Examples of such carbonizing agents include polyhydric alcohols such as pentaerythritol, dipentaerythritol, and trimethylolpropane (excluding the above-mentioned alicyclic polyhydric alcohols); starch, casein, and the like, and one or more selected from these can be used. Among these, pentaerythritol, dipentaerythritol, and the like are preferably used.

[0020] The mixing ratio of the carbonizing agent is preferably 5 to 600 parts by mass (more preferably 20 to 300 parts by mass, and even more preferably 40 to 150 parts by mass) per 100 parts by mass (solid content) of the binder. By using the carbonizing agent in this range, the dehydration cooling effect and the action of forming a carbonized heat insulating layer can be exerted, and good performance can be obtained in terms of heat insulation and fire resistance. The mixing ratio of the alicyclic polyhydric alcohol is preferably 0.5 to 50 mass% (more preferably 1.0 to 30 mass%, and even more preferably 1.5 to 20 mass%) of the total amount of the carbonizing agent. By keeping the mixing ratio within this range, it is possible to prevent the carbonized heat insulating layer from being burned and incinerated, even if the carbonized heat insulating layer is exposed to fire for a long period of time or is located close to the source of the fire.

[0021] The coating formed by the coating material of the present invention has excellent expandability at 200°C or higher (more preferably 250°C or higher) due to the interaction of the above-mentioned components, and forms a carbonized insulating layer. The expandability can be adjusted by the blending ratio of each component depending on the desired fire resistance. In particular, when the blending ratio of each component satisfies the above-mentioned range, the coating material of the present invention has excellent expandability, and the expansion ratio is preferably 20 times or higher (more preferably 25 times or higher, and even more preferably 30 times or higher). The upper limit of the expansion ratio is preferably 60 times or lower (more preferably 55 times or lower, and even more preferably 50 times or lower). A carbonized heat insulating layer formed with such high foaming is more likely to be reduced to ashes by combustion when exposed to fire for a long period of time or when it is close to the source of the fire, compared to a carbonized heat insulating layer formed with low foaming. To address this problem, the present invention contains an alicyclic polyhydric alcohol as a carbonizing agent, which makes it possible to suppress the reduction to ashes by combustion of a highly foamed carbonized heat insulating layer. The above expansion ratio was measured using a test specimen prepared by applying a coating material to 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 to a dry film thickness of 1.5 mm. The test specimen was then heated to 50 kW / m on the surface of the test specimen using an electric heater (CONE III, manufactured by Toyo Seiki Co., Ltd.) in accordance with the ISO 5660-1 cone calorimeter method. 2After cooling, the thickness of the carbonized heat insulating layer formed is measured and calculated as a ratio to the initial film thickness.

[0022] The coating material of the present invention may contain a filler in addition to the above components. The filler can enhance the effect of maintaining the strength of the carbonized heat insulating layer. There are no particular limitations on the filler as long as it has this effect, and known fillers can be used. Examples include talc, calcium carbonate, sodium carbonate, aluminum oxide, titanium oxide, zinc oxide, silica, clay, shirasu, mica, silica sand, silica stone powder, quartz powder, and barium sulfate, and one or more selected from these can be used.

[0023] The blending ratio of the filler is preferably 10 to 300 parts by mass (more preferably 20 to 250 parts by mass, and even more preferably 30 to 160 parts by mass) per 100 parts by mass (solid content) of the binder. By using this range, the strength of the carbonized heat insulating layer can be maintained and good fire resistance can be obtained.

[0024] Furthermore, the dressing material of the present invention may contain metal hydrates, fibers, and the like in addition to the above components.

[0025] Metal hydrates exhibit endothermic properties due to dehydration reactions or the like when the temperature rises, and are different from the fillers and flame retardants. Examples of such metal hydrates include aluminum hydroxide and magnesium hydroxide, and one or more selected from these can be used. The average particle size of the metal hydrate 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).

[0026] The blending ratio of the metal hydrate is preferably 0 to 30 parts by mass, more preferably 0.5 to 20 parts by mass, and even more preferably 1 to 10 parts by mass, relative to 100 parts by mass of the solid content of the binder.

[0027] The fibers can improve the coating thickness and suppress cracking of the coating. Furthermore, the fibers can prevent the coating from sagging during temperature rises due to fires and can also improve the thermal conductivity of the coating. As a result, the coating exhibits excellent foaming properties, forms a uniform carbonized heat insulating layer, and improves the heat-resistant protection performance of the substrate. Examples of such fibers 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, polychlor fibers, boronosic fibers, polypropylene fibers, and cellulose fibers, 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. One or more fibers selected from these can be used. Among these, inorganic fibers are preferred, and artificial mineral fibers such as rock wool fibers, slag wool fibers, glass fibers, and ceramic fibers are particularly preferred.

[0028] The size of the fibers (fiber length and fiber diameter) may be set according to the specifications of the coating material, the substrate to which it is applied, the applicator, etc., and it is preferable that the average fiber length is preferably within the range of 10 to 1000 μm (more preferably 15 to 800 μm, and even more preferably 20 to 600 μm), and the average fiber diameter is preferably within the range of 0.5 to 10 μm (more preferably 1 to 8 μm). The aspect ratio (fiber length / fiber diameter) is preferably 3 to 300 (more preferably 5 to 200). When these ranges are satisfied, the above effects can be further enhanced.

[0029] The blending ratio of the fibers is preferably 0 to 30 parts by mass (more preferably 0.5 to 25 parts by mass, and even more preferably 1 to 20 parts by mass) relative to 100 parts by mass of the solid content of the binder.

[0030] Furthermore, in addition to the above components, the coating material may contain various additives as needed. The additives may be any additives that do not significantly impair the effects of the present invention, and examples thereof include pigments, wetting agents, plasticizers, lubricants, preservatives, antifungal agents, anti-algae agents, antibacterial agents, thickeners, dispersants, antifoaming agents, crosslinking agents, ultraviolet absorbers, light stabilizers, antioxidants, dilution solvents, etc.

[0031] The dressing of the present invention can be produced by uniformly mixing the above-mentioned components by a conventional method. The dressing of the present invention can be in the form of a coating material containing the above-mentioned components, or a coating material previously formed into a sheet. When the coating material is molded into a sheet in advance, the above-mentioned components are mixed uniformly, and the resulting mixture is molded by a known method. When mixing the components, a solvent may be added or heating may be performed as necessary. When a binder in the form of beads or pellets is used, the binder may be heated to its softening temperature using a heating device, and the components may be mixed while being kneaded using a kneader or the like.

[0032] The coating material of the present invention can exert its effects by applying or adhering to a substrate to which fire resistance should be imparted. Substrates include structures such as buildings and civil engineering structures, specifically, various substrates such as walls, pillars, floors, beams, roofs, stairs, ceilings, and doors. Applicable substrates include, for example, concrete, mortar, siding boards, extruded moldings, gypsum boards, perlite boards, bricks, plastics, wood, metals, steel frames (steel), glass, and porcelain tiles. These substrates may already have a coating formed on their surface, may have undergone some kind of surface treatment (rust prevention treatment, flame retardant treatment, etc.), or may have wallpaper applied to them.

[0033] When applying the coating material (paint material) to the substrate, it is sufficient to apply one or several coats using a spray, roller, brush, trowel, spatula, or other application tool. When applying, the paint can be diluted with water or solvent, if necessary. Sheet-type coating materials can also be attached using adhesives, nails, tacks, etc.

[0034] The thickness of the covering material of the present invention may be appropriately set depending on the application site, etc., but is preferably about 0.2 to 10 mm, more preferably about 0.5 to 6 mm. By covering with such a covering material, excellent fire resistance can be exhibited when exposed to high temperatures such as during a fire.

[0035] In the present invention, a topcoat layer can be laminated as needed to protect the coating formed from the coating material. Such a topcoat layer can be formed by applying a known water-based or solvent-based paint. For example, acrylic resin-based, urethane resin-based, acrylic silicone resin-based, fluororesin-based paint, etc. can be used as the topcoat layer. These can be applied by known painting methods, and painting tools such as sprays, rollers, and brushes can be used. [Example]

[0036] The following examples will be given to clarify the features of the present invention, but the present invention is not limited to these examples.

[0037] The components used were as follows: Binder [A]: urethane resin {polyether polyol (hydroxyl value 24 mg KOH / g, solid content 100% by mass), and hexamethylene diisocyanate (NCO content 23.5%, solid content 100% by mass)} Binder [B]: Solvent-soluble acrylic resin (solid content 50% by mass, mineral spirit solution) Binder [C]: Vinyl acetate emulsion (solid content 50% by mass, medium: water) Flame retardant: Ammonium polyphosphate Foaming agent: Melamine Carbonizing agent [A]: Dipentaerythritol Carbonizing agent [B]: Spiroglycol (3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane) Filler: Titanium oxide

[0038] ○Production of coating materials (Coating material 1) To 90 parts by mass (solid content) of the polyether polyol of the binder [A], 380 parts by mass of flame retardant, 75 parts by mass of foaming agent, 90 parts by mass of filler, 90 parts by mass of carbonizing agent [A], 3 parts by mass of carbonizing agent [B], 90 parts by mass of solvent (xylene), and additives (dispersant, antifoaming agent, catalyst, etc.) were added and mixed uniformly to prepare the main compound. Next, 10 parts by mass (solid content) of hexamethylene diisocyanate as the binder [A] and 10 parts by mass of the solvent (xylene) were uniformly mixed to prepare a curing agent. The base resin and curing agent were mixed together to produce a coating material 1. (Coating material 2) To 90 parts by mass (solids) of the polyether polyol binder [A], 380 parts by mass of flame retardant, 75 parts by mass of foaming agent, 90 parts by mass of filler, 90 parts by mass of carbonizing agent [A], 5 parts by mass of carbonizing agent [B], 90 parts by mass of solvent (xylene), and additives (dispersant, antifoaming agent, catalyst, etc.) were added and mixed uniformly to prepare the main agent. Next, 10 parts by mass (solid content) of hexamethylene diisocyanate as the binder [A] and 10 parts by mass of the solvent (xylene) were uniformly mixed to prepare a curing agent. The base resin and curing agent were mixed together to produce a coating material 2. (Coating material 3) To 90 parts by mass (solids) of the polyether polyol binder [A], 380 parts by mass of flame retardant, 75 parts by mass of foaming agent, 90 parts by mass of filler, 90 parts by mass of carbonizing agent [A], 10 parts by mass of carbonizing agent [B], 90 parts by mass of solvent (xylene), and additives (dispersant, antifoaming agent, catalyst, etc.) were added and mixed uniformly to prepare the main resin. Next, 10 parts by mass (solid content) of hexamethylene diisocyanate as the binder [A] and 10 parts by mass of the solvent (xylene) were uniformly mixed to prepare a curing agent. The base resin and curing agent were mixed together to produce the coating material 3. (Coating material 4) Coating material 4 was produced by adding 380 parts by mass of flame retardant, 75 parts by mass of foaming agent, 90 parts by mass of filler, 90 parts by mass of carbonizing agent [A], 5 parts by mass of carbonizing agent [B], and 100 parts by mass of solvent (mineral spirits) to 100 parts by mass of binder [B] (solid content) and mixing uniformly. (Coating material 5) To 100 parts by mass (solid content) of binder [C], 380 parts by mass of flame retardant, 75 parts by mass of foaming agent, 90 parts by mass of filler, 90 parts by mass of carbonizing agent [A], 5 parts by mass of carbonizing agent [B], and additives (dispersant, antifoaming agent, catalyst, etc.) were added and mixed uniformly to produce coating material 5. (Coating material 6) To 90 parts by mass (solids) of the polyether polyol binder [A], 380 parts by mass of flame retardant, 75 parts by mass of foaming agent, 90 parts by mass of filler, 95 parts by mass of carbonizing agent [A], 90 parts by mass of solvent (xylene), and additives (dispersant, antifoaming agent, catalyst, etc.) were added and mixed uniformly to prepare the main compound. Next, 10 parts by mass (solid content) of hexamethylene diisocyanate as the binder [A] and 10 parts by mass of the solvent (xylene) were uniformly mixed to prepare a curing agent. The base resin and curing agent were mixed together to produce a coating material 6.

[0039] (Test Examples 1 to 6) The coating material was sprayed onto the entire surface of a steel plate (150mm long x 70mm wide x 1.6mm thick) that had been previously coated with an anti-rust paint (dry film thickness 1.5mm), and then cured at room temperature (25°C) for 7 days to serve as the test specimen, and the following evaluations were carried out. <Fire resistance rating 1> Based on the ISO 5660-1 cone calorimeter method, an electric heater (CONE III, manufactured by Toyo Seiki Co., Ltd.) was used to apply 50 kW / m 2 The expansion ratio and the backside temperature of the steel plate were measured after radiating radiant heat of 10000000000000 for 15 minutes. The evaluation criteria were as follows. The results are shown in Table 1. (Expansion ratio) AA: Expansion ratio over 30 times A: Expansion ratio over 25 times and up to 30 times B: Expansion ratio over 20 times and up to 25 times C: Expansion ratio over 10 times and up to 20 times D: Expansion ratio up to 10 times (Backside temperature) AA: Less than 430°C A: 430°C or higher and up to 470°C B: 470°C or higher and up to 500°C C: 500°C or higher and up to 550°C D: More than 550°C (Density evaluation) The specimens for which the expansion ratio was measured were cut, and the density of the carbonized insulation layer on the cross section was visually confirmed. The evaluation criteria were a four-point scale (excellent: A>B>C>D: poor), with high density being rated "A" and low density being rated "D."

[0040] <Fire resistance rating 2> Based on the ISO 5660-1 cone calorimeter method, an electric heater (CONE III, manufactured by Toyo Seiki Co., Ltd.) was used to apply 50 kW / m 2 The cross section of the carbonized heat insulating layer formed after radiating radiant heat of 1000 kJ / h for 30 minutes was checked, and the proportion of the ash (white) area was calculated. (Density evaluation) The test specimens for which the expansion ratio was measured were cut, and the density of the carbonized insulation layer on the cross section was visually confirmed. The evaluation criteria were a four-point scale (excellent: A>B>C>D: poor), with high density being rated as "A" and low density being rated as "D." (Ashing resistance evaluation) In the heat resistance evaluation 2 above, the cross section of the carbonized insulation layer formed after radiant heat was radiated for 30 minutes was checked, and the proportion of the ashed (white) area was calculated. The evaluation criteria were a four-point scale (excellent: A>B>C>D: poor), with little ashing being rated as "A" and advanced ashing being rated as "D." The evaluation criteria were as follows. The results are shown in Table 1.

[0041] [Table 1]

[0042] Test Examples 1 to 6 were all found in Heat Resistance Evaluation 1 to have excellent foaming properties, were capable of stably forming a carbonized heat insulating layer, and exhibited sufficient fire resistance. In particular, in Test Examples 1 to 5, even in Heat Resistance Evaluation 2 (high temperature extended heating test), the incineration of the carbonized heat insulating layer was sufficiently suppressed, and even more excellent fire resistance was achieved. On the other hand, in Test Example 6, in Heat Resistance Evaluation 2 (high temperature extended heating test), the ashing of the carbonized layer progressed slightly, and the density decreased slightly.

Claims

1. A thermally expandable coating material comprising a binder, a flame retardant, a foaming agent, and a carbonizing agent, The coating material, wherein the carbonizing agent contains an alicyclic polyhydric alcohol.

2. 2. The coating material according to claim 1, wherein the alicyclic polyhydric alcohol includes an alicyclic polyhydric alcohol having 6 to 20 carbon atoms.

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