Thermally expandable fireproof sheet

Abstract

To provide a thermally expandable fireproof sheet which has excellent fire resistance and barely degrades the same even when exposed to moisture.SOLUTION: A thermally expandable fireproof sheet is made of matrix resin and thermally expandable black lead and has a leaching rate of 3% or less after being immersed in deionized water at 60°C for one week.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a thermally expandable fire-resistant sheet. [Background technology]

[0002] In the field of construction, for fire prevention, thermally expandable fire-resistant sheets, in which inorganic materials that expand when heated are mixed into a matrix resin, are being used for building materials such as fittings, pillars, and wall materials. Such thermally expandable fire-resistant sheets expand when heated, and the combustion residue forms a fire-resistant insulation layer, thereby achieving fire-resistant insulation performance.

[0003] However, when a thermally expandable fire-resistant sheet is used in a location exposed to the elements or in a location subject to high humidity due to condensation or the like, the components may dissolve, causing a decrease in performance and a defective appearance.

[0004] Patent Document 1 discloses a fire-resistant resin composition comprising a thermoplastic resin, a phosphorus compound, neutralized thermally expandable graphite, and an inorganic filler, the total content of the phosphorus compound and neutralized thermally expandable graphite being 20 to 200 parts by weight, the inorganic filler being 50 to 500 parts by weight, and the weight ratio of neutralized thermally expandable graphite:phosphorus compound being 9:1 to 1:100, relative to 100 parts by weight of the thermoplastic resin, wherein the phosphorus compound is ammonium polyphosphate. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 09-227716 Summary of the Invention [Problem to be solved by the invention]

[0006] As described in Patent Document 1, conventional thermally expandable fire-resistant sheets usually contain a phosphorus compound in addition to thermally expandable graphite. However, phosphorus compounds are weak against water and dissolve and hydrolyze, so they cannot be used in areas where water or moisture is present, and the areas where they can be used are limited.

[0007] An object of the present invention is to provide a thermally expandable fire-resistant sheet which is excellent in fire resistance and is resistant to deterioration in performance even when exposed to moisture. [Means for solving the problem]

[0008] In order to solve the above problems, the following aspects of the present invention are provided.

[0009] Item 1. A heat-expandable fire-resistant sheet containing a matrix resin and heat-expandable graphite, the elution rate of which is 3% or less after immersion in pure water at 60°C for one week.

[0010] Item 2. The compressive strength of the expansion residue after heating at 600°C for 30 minutes is 0.2kgf / cm 2 Item 2. The heat-expandable fire-resistant sheet according to item 1.

[0011] Item 3. The thermally expandable fire-resistant sheet according to item 1 or 2, having a phosphorus content of 10% by mass or less.

[0012] Item 4. The thermally expandable fire-resistant sheet according to any one of Items 1 to 3, wherein the content of thermally expandable graphite is 15% by mass or more and less than 60% by mass.

[0013] Item 5. The composition according to any one of claims 1 to 4, which contains a poorly water-soluble phosphorus compound and has a phosphorus content of 0.5% by mass or more. 5. The heat-expandable fire-resistant sheet according to any one of claims 4 to 4.

[0014] Item 6. The thermally expandable fire-resistant sheet according to any one of items 1 to 5, which contains a poorly water-soluble phosphorus compound, and the content of the poorly water-soluble phosphorus compound is 3 mass % or more.

[0015] Item 7. The thermally expandable fire-resistant sheet according to item 5 or 6, wherein the water-insoluble phosphorus compound is at least one selected from ammonium polyphosphate, aluminum phosphite, aluminum diphosphate, aluminum diphosphate, aluminum triphosphate, aluminum metaphosphate, condensed aluminum phosphate, melam polyphosphate, melamine polyphosphate, melem polyphosphate, and water-insoluble phosphoric acid esters.

[0016] Item 8. The thermally expandable fire-resistant sheet according to any one of Items 1 to 4, containing at least one water-insoluble phosphorus compound selected from ammonium polyphosphate, aluminum phosphite, aluminum monophosphate, aluminum diphosphate, aluminum triphosphate, aluminum metaphosphate, condensed aluminum phosphate, melam polyphosphate, melamine polyphosphate, melem polyphosphate, and water-insoluble phosphoric acid esters. Effect of the Invention

[0017] According to the intumescent fire-resistant sheet of the present invention, it is possible to suppress the deterioration of performance due to exposure to moisture while maintaining excellent fire resistance. [Brief description of the drawings]

[0018] [Figure 1] 1 is a schematic diagram showing an example in which the thermally expandable fire-resistant sheet of the present invention is applied to a door. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment in which the present invention is embodied in a thermally expandable fire-resistant sheet will be described.

[0020] The thermally expandable fireproof sheet of the present invention contains a matrix resin and thermally expandable graphite, and has an elution rate of 3% or less after immersion in pure water at 60° C. for one week. The elution rate is (Mass of precipitate in immersion water) / (Mass of thermally expandable fireproof sheet before immersion) x 100(%) It is calculated as follows.

[0021] The thermally expandable fire-resistant sheet of the present invention has an elution rate of 3% or less after immersion in pure water at 60° C. for one week, and preferably has an elution rate of 1.5% or less after immersion in pure water at 60° C. for one week. This configuration makes it possible to provide a thermally expandable fire-resistant sheet that maintains excellent fire resistance and further suppresses deterioration in performance even when exposed to moisture.

[0022] Matrix resins include, for example, thermoplastic resins, thermoset resins, elastomers, rubber materials, and combinations thereof.

[0023] Examples of thermoplastic resins include polyolefin resins such as polypropylene resin, polyethylene resin, poly(1-)butene resin, and polypentene resin, polyester resins such as polyethylene terephthalate, polystyrene resin, acrylonitrile-butadiene-styrene (ABS) resin, ethylene-vinyl acetate copolymer (EVA), polycarbonate resin, polyphenylene ether resin, (meth)acrylic resin, polyamide resin, polyvinyl chloride resin (PVC), chlorinated polyvinyl chloride resin (CPVC), novolac resin, polyurethane resin, and synthetic resins such as polyisobutylene.

[0024] Examples of the thermosetting resin include synthetic resins such as polyurethane resin, phenol resin, epoxy resin, urea resin, melamine resin, unsaturated polyester resin, and polyimide.

[0025] Examples of the elastomer include olefin-based elastomers, styrene-based elastomers, ester-based elastomers, amide-based elastomers, vinyl chloride-based elastomers, and combinations of these.

[0026] Examples of rubber substances include natural rubber, isoprene rubber, butadiene rubber, 1,2-polybutadiene rubber, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, butyl rubber, chlorinated butyl rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber (EPDM), chlorosulfonated polyethylene, acrylic rubber, epichlorohydrin rubber, multi-vulcanized rubber, non-vulcanized rubber, silicone rubber, fluororubber, and urethane rubber.

[0027] These synthetic resins, elastomers and / or rubber materials may be used alone or in combination of two or more.

[0028] Among these synthetic resins, elastomers and / or rubber materials, non-vulcanized rubbers such as butyl rubber, polyolefin resins, olefin-based thermoplastic elastomers (TPO), and ethylene-propylene-diene rubbers (EPDM) are preferred in order to obtain flexibility and rubber-like properties. In terms of fire resistance, polyvinyl chloride resins (PVC), chlorinated polyvinyl chloride (CPVC), and EVA resins are preferred. From the viewpoint of increasing the flame retardancy of the resin itself to improve fire protection performance, epoxy resins and phenolic resins are preferred.

[0029] The content of the matrix resin in the thermally expandable fireproof sheet is not particularly limited, but is preferably 10 to 60 mass%, more preferably 20 to 60 mass%, and even more preferably 20 to 50 mass% from the viewpoints of mechanical strength, moldability, and fire resistance. A matrix resin content of 10 mass% or more is advantageous in terms of mechanical strength and moldability, and a content of 60 mass% or less is advantageous in terms of fire resistance.

[0030] Thermally expandable graphite is a conventionally known substance that expands when heated. Thermally expandable graphite is produced by treating powders of natural scaly graphite, pyrolytic graphite, kish graphite, or the like with an inorganic acid and a strong oxidizing agent to produce a graphite intercalation compound. Examples of inorganic acids include concentrated sulfuric acid, nitric acid, and selenic acid. Examples of strong oxidizing agents include concentrated nitric acid, perchloric acid, perchlorates, permanganates, dichromates, and hydrogen peroxide. Thermally expandable graphite is a crystalline compound that maintains the layered structure of carbon.

[0031] The thermally expandable graphite may be optionally neutralized, that is, the thermally expandable graphite obtained by the acid treatment as described above is further neutralized with ammonia, an aliphatic lower amine, an alkali metal compound, an alkaline earth metal compound, or the like.

[0032] The content of the thermally expandable graphite in the thermally expandable fireproof sheet is not particularly limited, but is preferably 5 to 60 mass%, and more preferably 15 mass% or more. When the content of the thermally expandable graphite is 15 mass% or more, expansion more suitable for preventing the passage of fire is obtained. When the content of the thermally expandable graphite is less than 60 mass%, it is preferable in terms of fire resistance and mechanical strength of the thermally expandable fireproof sheet.

[0033] The particle size of the thermally expandable graphite is preferably 20 to 200 mesh. If the particle size is 200 mesh or smaller, the degree of expansion of the graphite is sufficient to obtain an expandable insulating layer; Mesh or larger values ​​provide good dispersibility when mixed into resin.

[0034] The average particle size of the thermally expandable graphite is not particularly limited, but is preferably 200 to 1000 μm, and more preferably 200 to 600 μm. The average particle size of the thermally expandable graphite can be measured using a commercially available laser diffraction / scattering type particle size measuring device.

[0035] In the heat-expandable fireproof sheet of the present invention, it is preferable that the thermal decomposition temperature of the matrix resin is higher than the expansion start temperature of the heat-expandable graphite to be blended. Since the expansion start temperature of the expandable graphite is lower than the decomposition start temperature of the resin component, high expandability and high compressive strength after combustion can be obtained. The thermal decomposition temperature of the matrix resin refers to the temperature at which the solid resin component decomposes and mass loss begins to be confirmed. The reason for this is that when the heat-expandable fireproof sheet is heated, the expansion start temperature of the heat-expandable graphite is lower than the thermal decomposition temperature of the resin component. Therefore, the expandable graphite starts to expand before the resin component decomposes, and a hard insulating layer of the expandable graphite is formed. Then, the decomposition of the resin component is delayed, and the resin component is arranged so as to fill the gaps in the insulating layer, so it is considered that high compressive strength is maintained while high expandability is ensured.

[0036] The average aspect ratio of the thermally expandable graphite is not limited, but is preferably equal to or greater than 20. When the average aspect ratio of the thermally expandable graphite is equal to or greater than 20, the water resistance of the fire-resistant resin composition can be further improved.

[0037] The average aspect ratio of the thermally expandable graphite is preferably 20 or more, and more preferably 25 or more, but if the average aspect ratio is too high, cracks may occur, so that the average aspect ratio is preferably 1000 or less.

[0038] The average aspect ratio is the ratio of the average horizontal diameter to the vertical thickness. Since thermally expandable graphite is generally flat, the vertical direction can be considered to be the thickness direction and the horizontal direction the diameter direction, so the aspect ratio is the value obtained by dividing the maximum horizontal dimension by the vertical thickness.

[0039] Then, the aspect ratio is measured for a sufficiently large number of graphite pieces, i.e., 10 or more pieces, and the average value is taken as the average aspect ratio. The average particle size of the thermally expandable graphite can also be calculated as the average value of the maximum horizontal dimension.

[0040] The maximum horizontal dimension of the thermally expandable graphite and the thickness of the exfoliated graphite can be measured using, for example, a field emission scanning electron microscope (FE-SEM).

[0041] In order to suppress deterioration of performance due to exposure to moisture such as water and humidity, the heat-expandable fire-resistant sheet of the present invention preferably has as little phosphorus content as possible, and the phosphorus content in the heat-expandable fire-resistant sheet is preferably 10 mass% or less. Alternatively, when the heat-expandable fire-resistant sheet contains a poorly water-soluble phosphorus compound, the content of phosphorus derived from the poorly water-soluble phosphorus compound in the heat-expandable fire-resistant sheet or the phosphorus content in the heat-expandable fire-resistant sheet can be 0.5 mass% or more, preferably 3 mass% or more, more preferably 5 mass% or more.

[0042] When the phosphorus content derived from the poorly water-soluble phosphorus compound in the thermally expandable fire-resistant sheet or the phosphorus content in the thermally expandable fire-resistant sheet is 0.5 mass % or more, deterioration of performance due to exposure to moisture is suppressed.

[0043] The content of the poorly water-soluble phosphorus compound in the thermally expandable fire-resistant sheet is 3% by mass or more, preferably 5% by mass or more, more preferably 8% by mass or more. The content of the poorly water-soluble phosphorus compound in the thermally expandable fire-resistant sheet is 30% by mass or less, preferably 20% by mass or less, more preferably When the content of the poorly water-soluble phosphorus compound in the thermally expandable fire-resistant sheet is within the above range, deterioration of performance due to exposure to moisture is suppressed.

[0044] The phosphorus content can be calculated from the blend amount, or can be measured by known measuring methods such as fluorescent X-ray measurement and ICP analysis.

[0045] The water-insoluble flame retardant is defined as follows. When the matrix resin is other than vinyl chloride resin or chlorinated vinyl chloride resin, the water-insoluble flame retardant is defined as a compound having an elution rate of 3% or less when a compound containing 50% by mass of the matrix resin, 25% by mass of expanded graphite, and 25% by mass of the water-insoluble flame retardant is immersed in pure water at 60°C for one week. When the matrix resin is vinyl chloride resin or chlorinated vinyl chloride resin, the water-insoluble flame retardant is defined as a compound having an elution rate of 3% or less when a compound containing 30% by mass of the vinyl chloride resin or chlorinated vinyl chloride resin, 20% by mass of DIDP, 25% by mass of expanded graphite, and 25% by mass of the water-insoluble flame retardant is immersed in pure water at 60°C for one week. When the compound is a phosphorus compound, the water-insoluble flame retardant is a water-insoluble phosphorus compound.

[0046] The poorly water-soluble phosphorus compounds include poorly water-soluble inorganic phosphorus compounds and poorly water-soluble organic phosphorus compounds. Examples of poorly water-soluble inorganic phosphorus compounds include ammonium polyphosphate, aluminum phosphite, aluminum monophosphate, aluminum diphosphate, aluminum triphosphate, aluminum metaphosphate, condensed aluminum phosphate, and combinations thereof. Examples of poorly water-soluble organic phosphorus compounds include melam polyphosphate, melamine polyphosphate, melem polyphosphate, poorly water-soluble phosphoric acid esters acting as phosphorus-based plasticizers, and combinations thereof.

[0047] Examples of poorly water-soluble phosphate esters include trimethyl phosphate (TMP), triethyl phosphate (TEP), tributyl phosphate (TBP), tris(2-ethylhexyl) phosphate (TOP), triphenyl phosphate (TPP), tricresyl phosphate (TCP), trixylenyl phosphate (TXP), cresylphenyl phosphate (CDP), 2-ethylhexyl diphenyl phosphate, and spirocyclic diphosphonate compounds.

[0048] Preferably, the poorly water-soluble phosphorus compound is at least one selected from ammonium polyphosphate, aluminum phosphite, aluminum monophosphate, aluminum diphosphate, aluminum triphosphate, aluminum metaphosphate, condensed aluminum phosphate, melam polyphosphate, melamine polyphosphate, melem polyphosphate, and poorly water-soluble phosphoric acid esters. More preferably, the poorly water-soluble phosphorus compound is at least one selected from aluminum phosphite, melam polyphosphate, melamine polyphosphate, melem polyphosphate, and poorly water-soluble phosphoric acid esters. Even more preferably, the poorly water-soluble phosphorus compound is at least one selected from aluminum phosphite, melam polyphosphate, melamine polyphosphate, and poorly water-soluble phosphoric acid esters.

[0049] These compounds impart flame retardancy and water resistance to the thermally expandable fire resistant sheet.

[0050] The content of phosphorus, including phosphorus compounds, in the thermally expandable fireproof sheet is not particularly limited, but in order to suppress deterioration of performance due to exposure to moisture such as water and humidity, the phosphorus content is preferably 10 mass% or less, preferably 8 mass% or less, more preferably 5 mass% or less, and even more preferably 1 mass% or less. Note that the "phosphorus content" refers to the content of the phosphorus portion, and for example, when phosphorus is derived from a phosphorus compound, it refers to the phosphorus content in the phosphorus compound.

[0051] The thermally expandable fire-resistant sheet of the present invention may further contain an inorganic filler. When the expansion insulation layer is formed, the filler increases the heat capacity, suppresses heat transfer, and acts as an aggregate to improve the strength of the expansion insulation layer. The inorganic filler is not particularly limited, and examples thereof include metal oxides such as alumina, zinc oxide, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, and ferrite; metal hydroxides such as calcium hydroxide, magnesium hydroxide, aluminum hydroxide, and hydrotalcite; metal carbonates such as basic magnesium carbonate, calcium carbonate, magnesium carbonate, zinc carbonate, strontium carbonate, and barium carbonate; inorganic phosphates as flame retardants; calcium salts such as calcium sulfate, gypsum fiber, and calcium silicate; silica, diatomaceous earth, dawsonite, barium sulfate, tungsten, and the like. Examples of inorganic fillers include argon, clay, mica, montmorillonite, bentonite, activated clay, sepiolite, imogolite, sericite, glass fiber, glass beads, silica-based balloons, aluminum nitride, boron nitride, silicon nitride, carbon black, graphite, carbon fiber, carbon balloons, charcoal powder, various metal powders, potassium titanate, magnesium sulfate, lead zirconate titanate, zinc stearate, calcium stearate, aluminum borate, molybdenum sulfide, silicon carbide, stainless steel fiber, zinc borate, various magnetic powders, slag fiber, fly ash, dewatered sludge, etc. These inorganic fillers can be used alone or in combination.

[0052] The average particle size of the inorganic filler is preferably 0.5 to 100 μm, more preferably 1 to 50 μm. When the amount of inorganic filler added is small, the dispersibility greatly affects the performance, so a small average particle size is preferable, but if it is less than 0.5 μm, secondary aggregation occurs and the dispersibility deteriorates, so it is preferable that the average particle size is 0.5 μm or more. When the amount of inorganic filler added is large, as the filling progresses, the viscosity of the resin composition increases and the moldability decreases, but since the viscosity of the resin composition can be reduced by increasing the average particle size, a large average particle size is preferable, but if the average particle size exceeds 100 μm, the surface properties of the molded body and the mechanical performance of the resin composition decrease, so it is desirable that the average particle size is 100 μm or less. The average particle size of the inorganic filler can be measured by using a commercially available laser diffraction / scattering type particle size measuring device to determine the average particle size of a sufficiently large number of inorganic fillers, i.e., 10 or more.

[0053] Commercially available products of the inorganic fillers include, for example, aluminum hydroxide such as "H-42M" (manufactured by Showa Denko K.K.) with a particle size of 1 μm and "H-31" (manufactured by Showa Denko K.K.) with a particle size of 18 μm, and calcium carbonate such as "Whiten SB Red" (manufactured by Shiraishi Calcium Co., Ltd.) with a particle size of 1.8 μm and "BF300" (manufactured by Shiraishi Calcium Co., Ltd.) with a particle size of 8 μm. It is more preferable to use an inorganic filler having a large particle size in combination with one having a small particle size, as this combination allows for even higher loading.

[0054] The content of the inorganic filler in the thermally expandable fire-resistant sheet is not particularly limited, but is preferably 1 to 50 mass %.

[0055] The total content of the thermally expandable graphite and inorganic filler in the thermally expandable fire-resistant sheet is preferably 5 to 80% by mass, more preferably 5% by mass or more in terms of obtaining a sufficient amount of residue after combustion and thus obtaining sufficient fire resistance, and more preferably 80% by mass or less in terms of maintaining mechanical properties. The thermally expandable fire-resistant sheet may further contain a plasticizer.

[0056] The plasticizer is not particularly limited as long as it is a plasticizer generally used in the production of polyvinyl chloride resin molded articles. Phthalate plasticizers such as di-2-ethylhexyl phthalate (DOP), dibutyl phthalate (DBP), diheptyl phthalate (DHP), and diisodecyl phthalate (DIDP); Fatty acid ester plasticizers such as di-2-ethylhexyl adipate (DOA), diisobutyl adipate (DIBA), dibutyl adipate (DBA), etc.; Epoxidized ester plasticizers such as epoxidized soybean oil; Polyester plasticizers such as adipates and polyester adipates; Trimellitate ester plasticizers such as tri-2-ethylhexyl trimellitate (TOTM) and triisononyl trimellitate (TINTM); and process oils such as mineral oil. One or more plasticizers may be used.

[0057] If the amount of the plasticizer is small, the extrusion moldability tends to decrease, and if the amount is large, the obtained molded body tends to become too soft. Therefore, the content of the plasticizer is not limited, but is preferably 0 to 40% by mass, more preferably 5 to 35% by mass in the heat-expandable fire-resistant sheet.

[0058] The thermally expandable fire-resistant sheet of the present invention may further include a flame-retardant organic filler. The flame-retardant organic filler is an organic compound having heteroatoms such as nitrogen and phosphorus in addition to carbon and hydrogen, and is a compound that can impart flame retardancy to the thermally expandable sheet.

[0059] The compound constituting the flame-retardant organic filler is an organic material in which the proportion of carbon atoms in the compound is preferably 35% by mass or less, more preferably 30% by mass or less. By making the carbon proportion less than these upper limits, it becomes easier to impart fire resistance to the thermally expandable sheet. In addition, the carbon proportion is more preferably 3% by mass or more, even more preferably 7% by mass or more, and even more preferably 12% by mass or more. By making the carbon number greater than these lower limits, it becomes easier to improve processability.

[0060] The proportion of carbon atoms can be calculated from the chemical structure, and in the case of a polymer compound, can be measured by known elemental analysis.

[0061] The flame-retardant organic filler is preferably a nitrogen-containing flame retardant. More specifically, it is at least one selected from a melamine-based compound and a guanidine-based compound. The flame-retardant organic filler does not contain a poorly water-soluble phosphorus compound.

[0062] Examples of the melamine-based compounds include melamine or melamine derivatives such as melamine, melem, melam, and melon, and salts thereof. Examples of the salts of melamine or melamine derivatives include melamine cyanurate, melamine sulfate, melam pyrosulfate, melam organic sulfonate, melamine organic phosphonate, melamine organic phosphinate, and melamine borate.

[0063] Examples of the guanidine compounds include guanidine sulfamate, guanidine phosphate, and guanylurea phosphate.

[0064] These compounds may be used alone or in combination of two or more.

[0065] Among the above, melamine or a salt of a melamine derivative, or a guanidine compound is preferred. Specifically, at least one selected from melamine cyanurate, melamine sulfate, guanidine sulfamate, and guanidine phosphate is more preferred, and melamine cyanurate is even more preferred.

[0066] In the present invention, by using the above-mentioned melamine-based compound or guanidine-based compound, especially melamine cyanurate, as the flame-retardant organic filler, it becomes easier to obtain excellent fire resistance while maintaining good processability.

[0067] In the present invention, the content of the flame-retardant organic filler in the thermally expandable sheet is preferably 3 to 30 mass% based on the total amount of the thermally expandable sheet. In the above, for example, the ratio of the matrix component, which is a combustible component, is relatively low, so that even if the ratio of the inorganic filler is within a certain range, the fire resistance can be sufficiently improved. Also, when the flame-retardant organic filler is 30 mass% or less, the ratio of the matrix component is relatively high, so that the processability is good, and a large amount of inorganic filler can be contained, which is preferable in terms of fire resistance.

[0068] From the viewpoints of processability and flame retardancy, the content of the flame-retardant organic filler is preferably 5% by mass or more, more preferably 10% by mass or more, and is preferably 25% by mass or less, more preferably 20% by mass or less.

[0069] Examples of the other components that can be contained in the thermally expandable fireproof sheet include phenol-based, amine-based, and sulfur-based antioxidants, metal damage inhibitors, antistatic agents, stabilizers, crosslinking agents, lubricants, softeners, pigments, etc. These are used within the range that does not impair the physical properties.

[0070] The heat-expandable fireproof sheet is not particularly limited as long as it can provide insulation with its expansion layer when exposed to high temperatures such as during a fire, and the expansion layer has sufficient strength. 2 Heating conditions It is preferable that the expansion ratio after heating under low temperature for 30 minutes is 3 to 50 times. If the expansion ratio is 3 times or more, the burnt parts of the matrix components can be sufficiently filled, and if it is 50 times or less, the strength of the expansion layer is maintained and the effect of preventing flame penetration is maintained. The expansion ratio is calculated as (thickness of the test piece after heating) / (thickness of the test piece before heating) of the test piece of the thermally expandable fireproof sheet.

[0071] The thermally expandable fire-resistant sheet can be produced by coating or molding a fire-resistant resin composition obtained by mixing the above-mentioned matrix component, thermally expandable graphite, and optional other components. Molding includes press molding, extrusion molding, and injection molding. Coating or molding is well known in the art.

[0072] The thermally expandable fireproof sheet may be further laminated with a substrate. The substrate is laminated on one or both sides of the thermally expandable fireproof sheet. The substrate is usually a woven fabric or a nonwoven fabric, and the fibers used in the woven fabric or nonwoven fabric are not particularly limited, but are preferably noncombustible or semi-noncombustible materials, such as glass fibers, ceramic fibers, cellulose fibers, polyester fibers, carbon fibers, graphite fibers, and thermosetting resin fibers.

[0073] Here, "noncombustible materials" are materials that will not burn for 20 minutes after heating begins when exposed to the heat of a normal fire (see Article 2, item 9 of the Building Standards Act and Article 108-2, item 1 of the Enforcement Order of the Building Standards Act). Examples of noncombustible materials include carbon fiber, metal, and glass. "Semi-noncombustible materials" are materials that will not burn for 10 minutes after heating begins when exposed to the heat of a normal fire (see Article 1, item 5 of the Enforcement Order of the Building Standards Act).

[0074] The thickness of the heat-expandable fireproof sheet of the present invention is not particularly limited, but is preferably 0.2 to 10 mm. If it is 0.2 mm or more, heat insulation is exhibited, and if it is 10 mm or less, handling is good in terms of mass.

[0075] The heat-expandable fireproof sheet of the present invention has a compressive strength (also called residual hardness) of 0.2 kgf / cm when heated at 600°C for 30 minutes. 2 More preferred embodiments So, the compressive strength is 0.3kgf / cm 2 More than 2kgf / cm 2 More preferably: In an embodiment, the compressive strength is 0.5 kgf / cm 2 More than 2kgf / cm 2 The following is the result.

[0076] The expansion ratio is calculated as (thickness after heating) / (thickness before heating) of a test piece of the resin composition. The thermally expandable fireproof sheet of the present invention has an expansion ratio of 10 times or more when heated at 600° C. for 30 minutes. In a more preferred embodiment, the expansion ratio is 15 times or more and 60 times or less. In a further preferred embodiment, the expansion ratio is 20 times or more and 50 times or less.

[0077] The compressive strength of the expanded residue is calculated by compressing the heated test piece in a known compression testing machine and measuring the maximum compressive stress when compressed 10 mm from the top surface of the residue. In the present invention, however, it refers to the maximum stress measured when compressed 10 mm from the top surface of the residue using a compression testing machine with a three-point indenter having a diameter of 1 mm at a speed of 0.1 cm / sec.

[0078] The heat-expandable fire-resistant sheet of the present invention can be used to impart fire resistance to building materials. For example, it can be placed on fittings such as windows (including sliding windows, casement windows, sash windows, etc.), shoji screens, doors (i.e., doors), doors, and sliding doors; pillars; and walls of steel-framed concrete, etc., to reduce or prevent the intrusion of fire and smoke. In particular, since the heat-expandable fire-resistant sheet of the present invention has excellent shape retention, for example, if the heat-expandable fire-resistant sheet 1 is placed on the main body 12 of a door 10 as shown in Figure 1, the combustion residue is unlikely to collapse after combustion even if the sheet is placed vertically, and excellent fire resistance is exhibited.

[0079] Although the embodiment of the present invention has been specifically described above, the present invention is not limited to the above-described embodiment, and various modifications based on the technical concept of the present invention are possible.

[0080] The configurations, methods, steps, shapes, materials, and values ​​given in the above-described embodiments are merely examples, and configurations, methods, steps, shapes, materials, and values ​​different from these may be used as necessary.

[0081] Furthermore, the configurations, methods, steps, shapes, materials, and numerical values ​​of the above-described embodiments can be combined with one another without departing from the spirit of the present invention.

[0082] For example, the present invention may employ the following configuration. (1) A heat-expandable fire-resistant sheet containing a matrix resin and heat-expandable graphite, the leaching rate of which is 3% or less after immersion in pure water at 60°C for one week. With this configuration, it is possible to obtain a heat-expandable fire-resistant sheet that maintains excellent fire resistance and suppresses deterioration of performance even when exposed to moisture.

[0083] (2) The heat-expandable fire-resistant sheet according to (1), which has a dissolution rate of 1.5% or less after immersion in pure water at 60°C for one week. With this configuration, it is possible to obtain a thermally expandable fire-resistant sheet that maintains excellent fire resistance and is more effectively prevented from deteriorating in performance even when exposed to moisture.

[0084] (3) The compressive strength of the expansion residue after heating at 600°C for 30 minutes is 0.2 kgf / cm 2 The heat-expandable fire-resistant sheet according to (1) or (2) above. With this configuration, it is possible to obtain a thermally expandable fire-resistant sheet having high compressive strength after combustion.

[0085] (4) The compressive strength of the expansion residue after heating at 600°C for 30 minutes is 0.3 kgf / cm 2 Below Upper 2kgf / cm 2 The heat-expandable fire-resistant sheet according to (1) or (2) below. With this configuration, it is possible to obtain a thermally expandable fire-resistant sheet having an appropriately high compressive strength after combustion.

[0086] (5) The compressive strength of the expansion residue after heating at 600°C for 30 minutes is 0.5kgf / cm 2 Below Upper 2kgf / cm 2 The heat-expandable fire-resistant sheet according to (1) or (2) below. With this configuration, it is possible to obtain a thermally expandable fire-resistant sheet having an appropriately high compressive strength after combustion.

[0087] (6) The thermally expandable fire-resistant sheet according to any one of (1) to (5), having a phosphorus content of 10 mass % or less. With this configuration, deterioration of the performance of the thermally expandable fire-resistant sheet due to exposure to moisture such as water and humidity is suppressed.

[0088] (7) The thermally expandable fire-resistant sheet according to any one of (1) to (5), having a phosphorus content of 8 mass % or less. With this configuration, deterioration of the performance of the thermally expandable fire-resistant sheet due to exposure to moisture such as water and humidity is more effectively suppressed.

[0089] (8) The thermally expandable fire-resistant sheet according to any one of (1) to (5), having a phosphorus content of 5 mass % or less. With this configuration, deterioration of the performance of the thermally expandable fire-resistant sheet due to exposure to moisture such as water and humidity is more effectively suppressed.

[0090] (9) The thermally expandable fire-resistant sheet according to any one of (1) to (5), having a phosphorus content of 1 mass % or less. With this configuration, deterioration of the performance of the thermally expandable fire-resistant sheet due to exposure to moisture such as water and humidity is more effectively suppressed.

[0091] (10) The thermally expandable fireproof sheet according to any one of (1) to (9), wherein the content of thermally expandable graphite is 15% by mass or more and less than 60% by mass. With this configuration, a thermally expandable fire-resistant sheet can be obtained that is more suitable for preventing the passage of fire and has sufficient fire resistance and mechanical strength.

[0092] (11) The thermally expandable fire-resistant sheet according to any one of (1) to (10), which contains a poorly water-soluble phosphorus compound, and the content of the poorly water-soluble phosphorus compound is 3 mass % or more. With this configuration, deterioration of the performance of the thermally expandable fire-resistant sheet due to exposure to moisture is suppressed.

[0093] (12) The thermally expandable fire-resistant sheet according to any one of (1) to (10), which contains a poorly water-soluble phosphorus compound, and the content of the poorly water-soluble phosphorus compound is 5 mass % or more. With this configuration, deterioration of the performance of the thermally expandable fire-resistant sheet due to exposure to moisture is more effectively suppressed.

[0094] (13) The thermally expandable fire-resistant sheet according to any one of (1) to (10), which contains a poorly water-soluble phosphorus compound, the content of the poorly water-soluble phosphorus compound being 8 mass % or more. With this configuration, deterioration of the performance of the thermally expandable fire-resistant sheet due to exposure to moisture is more effectively suppressed.

[0095] (14) The thermally expandable fire-resistant sheet according to any one of (11) to (13), wherein the content of the poorly water-soluble phosphorus compound is 30 mass % or less. With this configuration, the thermally expandable fire-resistant sheet has good mechanical strength and fire resistance.

[0096] (15) The thermally expandable fire-resistant sheet according to any one of (11) to (13), wherein the content of the poorly water-soluble phosphorus compound is 20 mass % or less. With this configuration, the thermally expandable fire-resistant sheet has good mechanical strength and fire resistance.

[0097] (16) Any of (11) to (13) above, in which the content of poorly water-soluble phosphorus compounds is 10% by mass or less. The thermally expandable fire-resistant sheet according to any one of the preceding claims.

[0098] (17) The thermally expandable fire-resistant sheet according to any one of (1) to (16), wherein the phosphorus content derived from the poorly water-soluble phosphorus compound is 0.5 mass % or more. With this configuration, deterioration of the performance of the thermally expandable fire-resistant sheet due to exposure to moisture is suppressed.

[0099] (18) The thermally expandable fire-resistant sheet according to any one of (1) to (16), wherein the phosphorus content derived from the poorly water-soluble phosphorus compound is 3 mass % or more. With this configuration, deterioration of the performance of the thermally expandable fire-resistant sheet due to exposure to moisture is more effectively suppressed.

[0100] (19) The thermally expandable fire-resistant sheet according to any one of (1) to (16), wherein the phosphorus content derived from the poorly water-soluble phosphorus compound is 5 mass % or more. With this configuration, deterioration of the performance of the thermally expandable fire-resistant sheet due to exposure to moisture is more effectively suppressed.

[0101] (20) The heat-expandable fire-resistant sheet according to any one of (11) to (20), wherein the poorly water-soluble phosphorus compound is a poorly water-soluble inorganic phosphorus compound which is ammonium polyphosphate, aluminum phosphite, aluminum monophosphate, aluminum diphosphate, aluminum triphosphate, aluminum metaphosphate, condensed aluminum phosphate, or a combination thereof; a poorly water-soluble organic phosphorus compound which is melam polyphosphate, melamine polyphosphate, melem polyphosphate, a poorly water-soluble phosphate ester, or a combination thereof; or a combination of the poorly water-soluble inorganic phosphorus compound and a poorly water-soluble inorganic phosphorus compound. With this configuration, deterioration of the performance of the thermally expandable fire-resistant sheet due to exposure to moisture is more effectively suppressed.

[0102] (21) The heat-expandable fire-resistant sheet according to any one of (11) to (20), wherein the poorly water-soluble phosphorus compound is at least one selected from ammonium polyphosphate, aluminum phosphite, aluminum monophosphate, aluminum diphosphate, aluminum triphosphate, aluminum metaphosphate, condensed aluminum phosphate, melam polyphosphate, melamine polyphosphate, melem polyphosphate, and poorly water-soluble phosphoric acid esters. With this configuration, deterioration of the performance of the thermally expandable fire-resistant sheet due to exposure to moisture is more effectively suppressed.

[0103] (22) The thermally expandable fire-resistant sheet according to any one of (1) to (10), which contains a poorly water-soluble inorganic phosphorus compound which is ammonium polyphosphate, aluminum phosphite, aluminum monophosphate, aluminum diphosphate, aluminum triphosphate, aluminum metaphosphate, condensed aluminum phosphate, or a combination thereof; a poorly water-soluble organic phosphorus compound which is melam polyphosphate, melamine polyphosphate, melem polyphosphate, a poorly water-soluble phosphoric acid ester, or a combination thereof; or a poorly water-soluble phosphorus compound which is a combination of the poorly water-soluble inorganic phosphorus compound and a poorly water-soluble inorganic phosphorus compound. With this configuration, deterioration of the performance of the thermally expandable fire-resistant sheet due to exposure to moisture is more effectively suppressed.

[0104] (23) The thermally expandable fireproof sheet according to any one of (1) to (10), containing at least one water-soluble phosphorus compound selected from ammonium polyphosphate, aluminum phosphite, aluminum monophosphate, aluminum diphosphate, aluminum triphosphate, aluminum metaphosphate, condensed aluminum phosphate, melam polyphosphate, melamine polyphosphate, melem polyphosphate, and water-soluble phosphoric acid esters. With this configuration, deterioration of the performance of the thermally expandable fire-resistant sheet due to exposure to moisture is more effectively suppressed.

[0105] (24) The thermally expandable fire-resistant sheet according to any one of (1) to (23), wherein the matrix resin is a polyvinyl chloride resin, a chlorinated polyvinyl chloride resin, an ethylene-vinyl acetate copolymer (EVA), an epoxy resin, an olefin-based thermoplastic elastomer (TPO), an ethylene-propylene-diene rubber (EPDM), a chloroprene rubber, a silicone rubber, or a polyethylene or butyl rubber.

[0106] (25) The thermally expandable fire-resistant sheet according to any one of (1) to (24), wherein the thermally expandable fire-resistant sheet contains 10 to 60% by mass of a matrix resin. With this configuration, it is possible to obtain a thermally expandable fire-resistant sheet having excellent mechanical strength, formability and fire resistance.

[0107] (26) The heat-expandable fire-resistant sheet according to any one of (1) to (25), comprising, as the matrix resin, 10 to 60 mass% of a polyvinyl chloride resin or a chlorinated polyvinyl chloride resin, 5 to 35 mass% of a plasticizer, 5 to 60 mass% of heat-expandable graphite, and at least one poorly water-soluble phosphorus compound selected from ammonium polyphosphate, aluminum phosphite, aluminum diphosphate, aluminum diphosphate, aluminum triphosphate, aluminum metaphosphate, condensed aluminum phosphate, melam polyphosphate, melamine polyphosphate, melem polyphosphate, and poorly water-soluble phosphorus esters, wherein the phosphorus content in the heat-expandable fire-resistant sheet is 10 mass% or less. With this configuration, the intumescent fire-resistant sheet can maintain excellent fire resistance while suppressing deterioration of performance due to exposure to moisture.

[0108] (27) The thermally expandable fireproof sheet according to (26), wherein the plasticizer is a phthalate ester plasticizer such as di-2-ethylhexyl phthalate (DOP), dibutyl phthalate (DBP), diheptyl phthalate (DHP), diisodecyl phthalate (DIDP), etc.; a fatty acid ester plasticizer such as di-2-ethylhexyl adipate (DOA), diisobutyl adipate (DIBA), dibutyl adipate (DBA), etc.; an epoxidized ester plasticizer such as epoxidized soybean oil, etc.; a polyester plasticizer such as an adipic acid ester or an adipic acid polyester, etc.; a trimellitic acid ester plasticizer such as tri-2-ethylhexyl trimellitate (TOTM), triisononyl trimellitate (TINTM), etc.; or a process oil such as a mineral oil, etc.

[0109] (28) The heat-expandable fire-resistant sheet according to any one of (1) to (25), comprising 10 to 60 mass% of polyvinyl chloride resin or chlorinated polyvinyl chloride resin as the matrix resin, 5 to 35 mass% of a plasticizer, 5 to 60 mass% of heat-expandable graphite, and 1 to 50 mass% of an inorganic filler, and the phosphorus content in the heat-expandable fire-resistant sheet is 10 mass% or less. With this configuration, the intumescent fire-resistant sheet can maintain excellent fire resistance while suppressing deterioration of performance due to exposure to moisture.

[0110] (29) A thermally expandable fire-resistant sheet comprising 10 to 60 mass% of ethylene-vinyl acetate copolymer (EVA), epoxy resin, olefin-based thermoplastic elastomer (TPO), ethylene-propylene-diene rubber (EPDM), chloroprene rubber, silicone rubber, polyethylene or butyl rubber as the matrix resin, 5 to 60 mass% of thermally expandable graphite, and at least one water-insoluble phosphorus compound selected from ammonium polyphosphate, aluminum phosphite, aluminum monophosphate, aluminum diphosphate, aluminum triphosphate, aluminum metaphosphate, condensed aluminum phosphate, melam polyphosphate, melamine polyphosphate, melem polyphosphate and water-insoluble phosphoric acid esters, The thermally expandable fire-resistant sheet according to any one of (1) to (25), wherein the content of phosphorus in the sheet is 10 mass % or less. With this configuration, the intumescent fire-resistant sheet can maintain excellent fire resistance while suppressing deterioration of performance due to exposure to moisture.

[0111] (30) The heat-expandable fire-resistant sheet according to (29), further comprising 1 to 50 mass % of an inorganic filler. With this configuration, the intumescent fire-resistant sheet can maintain excellent fire resistance while suppressing deterioration of performance due to exposure to moisture.

[0112] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these. EXAMPLES

[0113] 1. Production of Thermally Expandable Fireproof Sheets of Examples 1 to 10 and 14 to 20 and Comparative Examples 1 and 5 The composition shown in Table 1 was placed in a roll set at 150°C and roll-kneaded for 5 minutes to obtain a blend. The resulting blend was press-molded at 130°C and a pressure of 10 MPa using a 1.5 mm spacer to obtain a sheet-like molded product with a thickness of 1.5 mm. Each component in the table is shown in parts by mass.

[0114] 2. Production of Thermally Expandable Fireproof Sheets of Examples 11 to 13 and 21 to 23 and Comparative Examples 2 to 4 The composition shown in Table 1 was fed to a planetary mixer (ARE500 manufactured by Thinky Corporation) and kneaded at room temperature for 3 minutes at 700 rpm to obtain a mixture. The mixture was then applied onto a PET film and press molded at 20°C and 10 MPa to obtain a sheet-like molded product with a thickness of 1.5 mm. The molded product was then placed in a thermostatic layer at 90°C for 10 hours to harden the sheet, producing a thermally expandable fireproof sheet.

[0115] 3. Production of Thermally Expandable Fireproof Sheets of Examples 24 to 41 The composition shown in Table 2 was placed in a roll set at 150°C and roll-kneaded for 5 minutes to obtain a blend. The resulting blend was press-molded at 130°C and a pressure of 10 MPa using a 1.5 mm spacer to obtain a sheet-like molded product with a thickness of 1.5 mm. Each component in the table is shown in parts by mass.

[0116] 4. Production of thermally expandable fireproof sheets of Examples 42 to 56 The compositions shown in Tables 2 and 3 were placed in a roll set at 150°C and roll-kneaded for 5 minutes to obtain a blend. The resulting blend was press-molded at 130°C and a pressure of 10 MPa using a 1.5 mm spacer to obtain a sheet-like molded product with a thickness of 1.5 mm. Each component in the tables is shown in parts by mass.

[0117] As the components in Tables 1 to 3, the following were used.

[0118] Polyvinyl chloride resin (product name: TK-1000, Shin-Etsu Chemical Co., Ltd.) Chlorinated polyvinyl chloride resin (product name: HA-53, Tokuyama Sekisui Chemical Co., Ltd.) EVA resin (product name: EV460, Mitsui DuPont Polychemicals Co., Ltd.) Epoxy resin (product name: FL-079, Mitsubishi Chemical Corporation) Epoxy resin (product name: E-807, Mitsubishi Chemical Corporation) TPO (product name: Milastomer 5020BS, Mitsui Chemicals, Inc.) EPDM (product name: ENB-EPT X-3012P, Mitsui Chemicals, Inc.) Chloroprene rubber (product name: Denka Chloroprene MT-100, Denka Company) Silicone rubber (product name: HCR SH502U, Dow Corning Toray Co., Ltd.) Polyethylene (product name: Novatec LD ZE41K, Mitsubishi Chemical Corporation) Butyl rubber (product name: JSR BUTYL065, JSR Corporation) Plasticizer: Diisodecyl phthalate (product name: DIDP, J-Plus) Thermally expandable graphite (product name: CA-60N, Air Water) Thermally expandable graphite (Product name: EXA50SE160, Fuji Graphite Industry Co., Ltd.) Thermally expandable graphite (product name: ADT351, expansion start temperature approx. 200℃, ADT) Inorganic filler: Calcium carbonate (Product name: Whiten BF-300, Bihoku Funka Kogyo Co., Ltd.) Flame retardant Ammonium polyphosphate (product name: AP-422, Clariant) Flame retardant Ammonium polyphosphate (product name: AP-462, Clariant) Flame retardant Aluminum phosphite (Product name: APA100, Taihei Chemical Industry Co., Ltd.) Flame retardant: Aluminum phosphate dibasic (product name: 100P, Taki Chemical Co., Ltd.) Flame retardant Melamine polyphosphate (Product name: MPP-A, Sanwa Chemical Co., Ltd.) Flame retardant: Melam polyphosphate (Product name: Phosmel (registered trademark) 200, Nissan Chemical Co., Ltd.) Flame retardant: Water-insoluble organophosphorus compound (product name: Exolit OP1230, Clariant) Flame retardant: Aluminum phosphate dibasic (Taihei Chemical Industry Co., Ltd.) Flame retardant: Aluminum phosphate tribasic (Taihei Chemical Industry Co., Ltd.) Flame retardant: Aluminum metaphosphate (Taihei Chemical Industry Co., Ltd.) Flame retardant: Condensed aluminum phosphate (Product name: K-WHITE #85, Teika Corporation) Flame retardant: Condensed aluminum phosphate (Product name: K-BOND #90, Teika Corporation) Flame retardant: Condensed aluminum phosphate (Product name: K-FRESH MZO, Teika Corporation) Flame retardant: Tricresyl phosphate (product name: Sanso Cizer TCP, New Japan Chemical Co., Ltd.) Flame retardant: Spirocyclic diphosphonate compound (product name: FCX-210, manufactured by Teijin Ltd.)

[0119] 5. Examination Evaluation Criteria (elution rate) Five test pieces (length 50 mm, width 50 mm, thickness 1.5 mm) were prepared from the molded sheets of Examples 1 to 56 and Comparative Examples 1 to 5, and each test piece was immersed in 200 g of pure water for one week in a sealed container at 60° C. After that, the samples were taken out, and the pure water was evaporated and dried at 60° C. for 96 hours, and the mass of the precipitate was measured. The dissolution rate was measured using the measured value.

[0120] (Expansion ratio) Test pieces (length 100 mm, width 100 mm, thickness 1.5 mm) and test pieces of the same shape prepared from the obtained molded sheets of Examples 1 to 56 and Comparative Examples 1 to 5 were immersed in 500 mL of pure water in a sealed container at 60°C for one week, and then the samples were taken out. The test pieces prepared by evaporating and drying the samples at 60°C for 96 hours were placed on the bottom of a stainless steel holder (101 mm square, height 80 mm), fed into an electric furnace, and heated at 600°C for 30 minutes. Thereafter, the height (highest part), width, length, and thickness of the test pieces were measured, and the expansion ratio was calculated by ((thickness of test piece after heating) / (thickness of test piece before heating)).

[0121] (Compressive strength) The heated test piece for which the expansion ratio had been measured was fed into a compression testing machine (Kato Tech Co., Ltd., "Finger Feeling Tester") and compressed at a speed of 0.1 cm / sec with a three-point indenter with a diameter of 1 mm. The maximum stress up to 10 mm of compression from the top surface of the residue was measured, and the compressive strength of the test piece after combustion was measured.

[0122] (judgement) Test pieces with a dissolution rate of more than 3% by mass were rated C. Test pieces with a dissolution rate of less than 3.0% by mass and more than 1.5% by mass were rated B, and those with a dissolution rate of less than 1.5% by mass were rated A.

[0123] 6. Test Results The measurement results of the expansion ratio, compressive strength and dissolution rate of the test pieces of Examples 1 to 56 and Comparative Examples 1 to 5 are shown in Table 1.

[0124] The thermally expandable fireproof sheet of Example 19 does not contain a phosphorus compound, and the thermally expandable fireproof sheets of Examples 1, 6, 7, 14, and 15 contain ammonium polyphosphate. The thermally expandable fireproof sheets of Examples 2, 8, 11, 18, 20, 21, 24, 27, 30, 33, 36, 39, 49, and 50 contain aluminum phosphite. The thermally expandable fireproof sheets of Examples 3, 9, 17, 25, 28, 31, 34, 37, 40, 55, and 56 contain melamine polyphosphate. The thermally expandable fireproof sheets of Examples 4, 10, 12, 16, 20, 26, 29, 32, 35, 38, 41, 51, and 52 contain melam polyphosphate. The thermally expandable fireproof sheets of Examples 5, 13, 23, 53, and 54 contain a poorly water-soluble organic phosphorus compound. The thermally expandable fireproof sheet of Example 22 contains aluminum monophosphate. The thermally expandable fireproof sheet of Example 42 contains aluminum diphosphate. The thermally expandable fireproof sheet of Example 43 contains aluminum triphosphate. The thermally expandable fireproof sheet of Example 44 contains aluminum metaphosphate. The thermally expandable fireproof sheets of Examples 45 to 47 contain condensed aluminum phosphate. Example 48 contains tricresyl phosphate.

[0125] The thermally expandable fireproof sheets of Examples 1 to 56 were good in terms of expansion ratio, compressive strength, and elution rate, but the thermally expandable fireproof sheets of Comparative Examples 1 to 5 had a large elution rate and poor water resistance. In addition, those with a small elution rate showed little change in compressive strength after elution and were able to maintain the compressive strength.

[0126] [Table 1]

[0127] [Table 2]

[0128] [Table 3]

Claims

1. A heat-expandable fire-resistant sheet containing a matrix resin and heat-expandable graphite, the sheet having an elution rate of 3% or less after immersion in pure water at 60°C for one week.

2. The compressive strength of the expansion residue after heating at 600°C for 30 minutes was 0.2 kgf / cm ２ The thermally expandable fire-resistant sheet according to claim 1.

3. The thermally expandable fire-resistant sheet according to claim 1 or 2, having a phosphorus content of 10 mass% or less.

4. The thermally expandable fireproof sheet according to any one of claims 1 to 3, wherein the content of thermally expandable graphite is 15% by mass or more and less than 60% by mass.

5. The heat-expandable fire-resistant sheet according to any one of claims 1 to 4, which contains a poorly water-soluble phosphorus compound and has a phosphorus content of 0.5 mass% or more.

6. The heat-expandable fire-resistant sheet according to any one of claims 1 to 5, comprising a poorly water-soluble phosphorus compound, the content of which is 3 mass% or more.

7. The heat-expandable fire-resistant sheet according to claim 5 or 6, wherein the water-insoluble phosphorus compound is at least one selected from ammonium polyphosphate, aluminum phosphite, aluminum monophosphate, aluminum diphosphate, aluminum triphosphate, aluminum metaphosphate, condensed aluminum phosphate, melam polyphosphate, melamine polyphosphate, melem polyphosphate, and water-insoluble phosphoric acid esters.

8. The thermally expandable fireproof sheet according to any one of claims 1 to 4, which contains at least one water-insoluble phosphorus compound selected from ammonium polyphosphate, aluminum phosphite, aluminum diphosphate, aluminum diphosphate, aluminum triphosphate, aluminum metaphosphate, condensed aluminum phosphate, melam polyphosphate, melamine polyphosphate, melem polyphosphate, and water-insoluble phosphoric acid esters.

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