Thermally expandable refractory

Abstract

Provided is a thermally expandable refractory material containing: at least one matrix component selected from the group consisting of a rubber and a resin; thermally expandable graphite; and a flexibility imparting agent, wherein both the rubber and the resin are solid at 23°C. When the thermally expandable refractory material is cut into a size of 25 mm × 25 mm × 2 mm and placed in a space of 6 mm in the thickness direction, and then heated at 400°C for 15 minutes in each space, the closed expansion ratio of the thermally expandable refractory material is at least 4.0 as obtained by dividing the area of the thermally expandable refractory material seen in the thickness direction by the area prior to heating.

Description

[Technical Field]

[0001] The present invention relates to a thermally expandable refractory material. [Background Art]

[0002] In the construction field, refractory materials are used in construction materials such as fittings, columns, and wall materials for fire prevention. As the refractory material, thermally expandable refractory materials in which heat-expandable graphite is blended into a resin in addition to a flame retardant, an inorganic filler, and the like are used (see, for example, Patent Document 1). Such a thermally expandable refractory material expands when heated, and the combustion residue forms a refractory heat-insulating layer, thereby exhibiting refractory heat-insulating performance. A thermally expandable refractory material containing heat-expandable graphite is provided, for example, in the gap between fittings such as doors and windows provided at openings of a building and frames such as door frames and window frames surrounding these fittings. In the event of a fire, the sheet expands in the thickness direction to close the gap between the fitting and the frame material, thereby preventing the spread of fire. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2017-141463 [Summary of the Invention] [Problems to be Solved by the Invention]

[0004] However, conventional thermally expandable refractory materials have strong anisotropy in the expansion direction. Specifically, they have the property of expanding well in the thickness direction and being less likely to expand in the plane direction. Therefore, in a space narrow in the thickness direction, such as the gap between a door and a door frame, there is a problem that the original expansion ability cannot be exhibited. Accordingly, an object of the present invention is to provide a thermally expandable refractory material that sufficiently expands in the plane direction. [Means for Solving the Problems]

[0005] As a result of diligent research, the inventors have found a solution to the above problem by providing a heat-expandable fire-resistant material containing at least one matrix component selected from the group consisting of rubber and resin (both solid at 23°C), thermally expandable graphite, and a flexibility imparter, thereby ensuring that the occlusion expansion ratio is above a certain level, and have completed the present invention. The present invention provides the following [1] to [7].

[0006] [1] A heat-expandable fire-resistant material comprising a matrix component consisting of at least one selected from the group consisting of rubber and resin, heat-expandable graphite, and a flexibility imparter, wherein both the rubber and resin are solid at 23°C, and when the heat-expandable fire-resistant material is cut to dimensions of 25 mm × 25 mm × 2 mm, placed in a space of 6 mm in the thickness direction, and then heated at 400°C for 15 minutes, the occluded expansion ratio obtained by dividing the area of ​​the heat-expandable fire-resistant material viewed from the thickness direction by the area before heating is 4.0 times or more. [2] The heat-expandable fire-resistant material according to [1], wherein the heat-expandable fire-resistant material further contains a flame retardant. [3] The thermally expandable fire-resistant material according to [1] or [2], wherein the flexibility-imparting agent is at least one selected from the group consisting of plasticizers, rubber processing oils, and liquid rubber. [4] The thermally expandable fire-resistant material according to [3], wherein the plasticizer is a non-phthalate plasticizer. [5] The thermally expandable fire-resistant material according to any one of [1] to [4], wherein the total content of the flexibility imparter is 30 to 80 parts by mass per 100 parts by mass of the matrix component. [6] The heat-expandable fire-resistant material according to any one of [1] to [5], wherein the Mooney viscosity of the heat-expandable fire-resistant material at 100°C is 80 or less. [7] The thermally expandable fire-resistant material according to any one of [1] to [6], wherein the rubber is a thermosetting rubber that does not contain halogens in its molecular structure. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a heat-expandable fire-resistant material that expands sufficiently in the planar direction. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram showing a thermally expandable fire-resistant material placed in space, viewed from the side. [Figure 2] This is a schematic diagram showing a thermally expandable refractory material viewed from the thickness direction before and after heating. [Figure 3] This is a schematic diagram showing how a heat-expandable fire-resistant material is arranged in a U-shaped jig. [Figure 4] This is a schematic diagram of a three-point bending test conducted on a heat-expandable refractory material after heating. [Modes for carrying out the invention]

[0009] [Thermally expandable fireproof material] The heat-expandable fire-resistant material of the present invention (hereinafter sometimes referred to as "fire-resistant material") has a closed-loop expansion ratio of 4.0 times or more. If the closed-loop expansion ratio is less than 4.0 times, the expansion in the planar direction will be insufficient, and the performance of the fire-resistant material cannot be fully exhibited when the fire-resistant material is placed in a narrow space in the thickness direction. From this viewpoint, the closed-loop expansion ratio is preferably 4.5 times or more, and more preferably 5.0 times or more. On the other hand, there is no particular upper limit to the closed-loop expansion ratio, but practically speaking, it is, for example, 15 times or less, preferably 10 times or less. In the present invention, the closed-loop expansion ratio can be increased by including a matrix component, heat-expandable graphite, and a flexibility imparter in the fire-resistant material. In particular, including a flexibility imparterer makes the fire-resistant material more susceptible to thermal expansion, making it easier to increase the closed-loop expansion ratio. In the present invention, the occlusion expansion ratio can be obtained by the following method. First, cut the fire-resistant material into a rectangular prism measuring 25mm x 25mm x 2mm, and place the cut pieces of fire-resistant material within a 6mm space in the thickness direction. However, if the thickness of the fire-resistant material is less than 2mm, it is best to stack two or more pieces of fire-resistant material together to make a total thickness of 2mm, and then integrate them by press molding or similar methods to create a measurement sample. More specifically, as shown in Figure 1, the refractory material 10 is placed in a space 12 with a height h of 6 mm within the jig 11. After heating the refractory material 10 at 400°C for 15 minutes, the occlusion expansion ratio can be obtained by dividing the area of ​​the refractory material 10 viewed from the thickness direction (shown in the right diagram of Figure 2, hereinafter sometimes referred to as "area after heating") by the area of ​​the refractory material 10 before heating (shown in the thickness direction, hereinafter sometimes referred to as "area before heating"), as shown in the left diagram of Figure 2. The space 12 is formed between two metal plates 13 (material: SUS) by arranging them with a 6 mm thick spacer in between, and fixing the two metal plates with a fixing member 14.

[0010] The heat-expandable fire-resistant material of the present invention contains a matrix component, heat-expandable graphite, and a flexibility-imparting agent. Each component will be described in detail below.

[0011] <Matrix Components> The fire-resistant material of the present invention contains a matrix component consisting of at least one selected from rubber and resin. Both rubber and resin are solid at 23°C.

[0012] (rubber) The rubber component is preferably a thermosetting rubber that does not contain halogens in its molecular structure. Thermosetting rubber is a type of rubber that is thermosetting even in heat-expandable fire-resistant materials, and examples include conjugated diene rubbers and other rubbers that have double bonds in their main chain. By using thermosetting rubber, it is possible to harden when heated and ensure that the residual strength of the fire-resistant material after thermal expansion is above a certain level. Therefore, it can exhibit excellent fire resistance, such as blocking flames and preventing the spread of fire. In addition, by using rubber that does not contain halogens in its molecular structure, it is possible to prevent the generation of toxic gases caused by halogens in the event of a fire. Examples of thermosetting rubbers containing no halogen in the molecular structure include conjugated diene rubbers such as natural rubber, isoprene rubber, butyl rubber (IIR), butadiene rubber (BR), 1,2-polybutadiene rubber, styrene-butadiene rubber (SBR), and acrylonitrile-butadiene rubber (NBR); and ethylene-propylene rubber, ethylene-propylene-diene rubber (EPDM), acrylic rubber, polyvulcanized rubber, unvulcanized rubber, silicone rubber, urethane elastomers, etc. Among these, from the viewpoints of increasing residue strength and expansion pressure, and improving fire resistance, the rubber is preferably at least one selected from the group consisting of acrylonitrile-butadiene rubber, butadiene rubber, styrene-butadiene rubber, butyl rubber, and ethylene-propylene-diene rubber. Further, it is more preferably at least one selected from the group consisting of acrylonitrile-butadiene rubber, butadiene rubber, and styrene-butadiene rubber. Among these, acrylonitrile-butadiene rubber is further preferable from the viewpoint of easily adjusting the area of the thermally expandable fire-resistant material after heating to a desired range. The nitrile content of the acrylonitrile-butadiene rubber is preferably 8 to 40% by mass, more preferably 10 to 35% by mass, and still more preferably 15 to 25% by mass. Acrylonitrile-butadiene rubber having a nitrile content in the above range easily increases the expansion pressure of the fire-resistant material and easily adjusts the blocking expansion ratio to a certain level or higher. The Mooney viscosity ML(1+4) at 100°C of the acrylonitrile-butadiene rubber is preferably 20 to 90, more preferably 30 to 80, and still more preferably 40 to 70. Acrylonitrile-butadiene rubber having a Mooney viscosity ML(1+4) at 100°C in the above range easily increases the expansion pressure of the fire-resistant material and easily adjusts the blocking expansion ratio to a certain level or higher.

[0013] As the styrene-butadiene rubber (SBR), a random copolymer of styrene and butadiene can be mentioned. The styrene content in the styrene-butadiene rubber is preferably 20 to 60% by mass, more preferably 25 to 50% by mass, and even more preferably 30 to 45% by mass. A styrene-butadiene rubber having a styrene content within the above range tends to easily increase the expansion pressure of a refractory material, and facilitates adjustment of the blocking expansion ratio to a certain value or higher. The Mooney viscosity ML(1+4) of styrene-butadiene rubber at 100°C is preferably 20 to 60, more preferably 30 to 55, and even more preferably 40 to 50. A styrene-butadiene rubber having a Mooney viscosity ML(1+4) at 100°C within the above range tends to easily increase the expansion pressure of a refractory material, and facilitates adjustment of the blocking expansion ratio to a certain value or higher. In the present invention, the Mooney viscosity ML(1+4) is measured in accordance with JIS K6300.

[0014] (Resin) The resin may be a thermoplastic resin or a thermosetting resin. Examples of the thermoplastic resin 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 resin (EVA), polycarbonate resin, polyphenylene ether resin, (meth)acrylic resins such as polymethyl methacrylate resin (PMMA), polyamide resin, polyvinyl chloride resin (PVC), novolak resin, polyurethane resin, polyisobutylene, and the like. Among thermoplastic resins, from the viewpoint of improving the fire resistance of the refractory material, at least one selected from the group consisting of polyvinyl chloride resin, ethylene-vinyl acetate copolymer resin, and (meth)acrylic resin is preferable, polyvinyl chloride resin and ethylene-vinyl acetate copolymer resin are more preferable, and polyvinyl chloride resin is even more preferable.

[0015] Examples of polyvinyl chloride resins (PVCs) include homopolymers of vinyl chloride monomer, copolymers of vinyl chloride monomer and monomers having unsaturated bonds copolymerizable with vinyl chloride monomer, and graft copolymers obtained by graft copolymerizing vinyl chloride monomer with polymers or copolymers other than vinyl chloride monomer. These may be used individually or in combination of two or more types. In this invention, chlorinated polyvinyl chloride resins, which are chlorinated products of polyvinyl chloride resins, are also included in the category of polyvinyl chloride resins. The degree of polymerization of the polyvinyl chloride resin is preferably 500 to 2000, and more preferably 800 to 1500.

[0016] The ethylene-vinyl acetate copolymer resin (EVA) may be a non-crosslinked ethylene-vinyl acetate copolymer resin or a high-temperature crosslinked ethylene-vinyl acetate copolymer resin. Furthermore, ethylene-vinyl acetate modified resins, such as saponified ethylene-vinyl acetate copolymers or hydrolyzed ethylene-vinyl acetates, can also be used as the ethylene-vinyl acetate copolymer resin. The ethylene-vinyl acetate copolymer resin preferably has a vinyl acetate content of 5 to 90% by mass, more preferably 8 to 50% by mass, and even more preferably 12 to 35% by mass, as measured in accordance with JIS K 6730 "Test Method for Ethylene-Vinyl Acetate Resin". The melt flow rate (MFR) of the ethylene-vinyl acetate copolymer resin at 190°C is preferably 0.5 to 15 g / 10 min, and more preferably 1 to 8 g / 10 min. The melt flow rate of the ethylene-vinyl acetate copolymer at 190°C is measured under a load of 2.16 kg and is measured in accordance with JIS K7210:1999.

[0017] The thermosetting resins mentioned above are not particularly limited, but examples include epoxy resins, polyurethane resins, phenolic resins, melamine resins, urea resins, unsaturated polyester resins, alkyd resins, and thermosetting polyimides. Among these, epoxy resins are preferred from the viewpoint of improving fire resistance.

[0018] The epoxy resin used in the present invention is not particularly limited, but examples include an epoxy compound alone, or a resin consisting of an epoxy compound as the main component and a curing agent. The epoxy compound is a compound having an epoxy group, and specifically, glycidyl ether type and glycidyl ester type are examples. The glycidyl ether type may be bifunctional or polyfunctional with three or more functions. The same applies to the glycidyl ester type. The epoxy compound may also contain a monofunctional compound to adjust the degree of crosslinking, etc. Among these, the bifunctional glycidyl ether type is preferred.

[0019] Examples of the above-mentioned bifunctional glycidyl ether type epoxy compounds include alkylene glycol types such as polyethylene glycol type and polypropylene glycol type, neopentyl glycol type, 1,6-hexanediol type, and hydrogenated bisphenol A type aliphatic epoxy compounds. Furthermore, aromatic epoxy compounds containing aromatic rings such as bisphenol A type, bisphenol F type, bisphenol AD ​​type, ethylene oxide-bisphenol A type, and propylene oxide-bisphenol A type can be cited. Among these, aromatic epoxy compounds such as bisphenol A type and bisphenol F type are preferred.

[0020] Examples of the glycidyl ester type epoxy compounds mentioned above include hexahydrophthalic anhydride type, tetrahydrophthalic anhydride type, dimer acid type, and p-oxybenzoic acid type epoxy compounds. Examples of glycidyl ether type epoxy compounds with three or more functionalities include phenol novolac type, orthocresol novolac type, DPP novolac type, and dicyclopentadiene phenol type. These epoxy compounds may be used individually or in combination of two or more. The epoxy resin may be an epoxy resin having an aromatic ring or an epoxy resin without an aromatic ring, but from the viewpoint of enhancing non-flammability, an epoxy resin having an aromatic ring is preferred.

[0021] Polyaddition-type or catalytic-type curing agents can be used. Examples of polyaddition-type curing agents include polyamines, acid anhydrides, polyphenols, and polymercaptans. Examples of catalytic-type curing agents include tertiary amines, imidazoles, and Lewis acid complexes. These curing agents may be used individually or in combination of two or more. The curing agent content is preferably in the range of 50 to 150 parts by mass per 100 parts by mass of the epoxy resin compound. If the content is 50 parts by mass or more, the epoxy resin compound will harden more easily, and if it is 150 parts by mass or less, an effect corresponding to the amount of curing agent added will be obtained.

[0022] The above matrix components may be used individually or in combination of two or more. As for the matrix component, it is preferable to use rubber, more preferable to use thermosetting rubber that does not contain halogens in its molecular structure, and even more preferable to use NBR. Furthermore, the matrix component content is preferably 15% by mass or more, more preferably 18% by mass or more, even more preferably 20% by mass or more, and preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less, based on the total amount of refractory material. When the matrix component content is above these lower limits, the shape retention of the refractory material is improved. When the matrix component content is below these upper limits, the amount of thermally expandable graphite, which will be described later, can be adjusted to be larger, thus improving refractory properties.

[0023] <Thermally expandable graphite> The refractory material of the present invention contains thermally expandable graphite. Thermally expandable graphite is a conventionally known substance that expands when heated, and is produced by acid-treating raw material powders such as natural scaly graphite, pyrolysis graphite, and quiche graphite with a strong oxidizing agent to generate graphite intercalation compounds. Examples of strong oxidizing agents include inorganic acids such as concentrated sulfuric acid, nitric acid, and selenic acid, as well as 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. The thermally expandable graphite may be neutralized. That is, the thermally expandable graphite obtained by treating it with a strong oxidizing agent as described above may be further neutralized with ammonia, aliphatic lower amines, alkali metal compounds, alkaline earth metal compounds, etc.

[0024] The content of thermally expandable graphite in the refractory material of the present invention is preferably 50 to 500 parts by mass, more preferably 70 to 250 parts by mass, and even more preferably 100 to 200 parts by mass, per 100 parts by mass of the matrix component. If the content of thermally expandable graphite is above these lower limits, it becomes easier to increase the expansion pressure of the thermally expandable refractory material and to adjust the occlusion expansion ratio to a certain level or higher. On the other hand, if the content of thermally expandable graphite is below these upper limits, the shape retention and processability are improved.

[0025] The thermally expandable graphite in this invention preferably has an average aspect ratio of 15 or more, more preferably 20 or more, and usually 1000 or less. When the average aspect ratio of the thermally expandable graphite is above these lower limits, it becomes easier to increase the expansion pressure of the refractory material. The aspect ratio of thermally expandable graphite is determined by measuring the maximum dimension (long axis) and minimum dimension (short axis) of 10 or more (e.g., 50) thermally expandable graphite objects, and then calculating the average of these ratios (maximum dimension / minimum dimension).

[0026] The average particle size of the thermally expandable graphite is preferably 50 to 500 μm, and more preferably 100 to 400 μm, from the viewpoint of achieving the desired expansion pressure. The average particle size of the thermally expandable graphite is determined by taking 10 or more (e.g., 50) thermally expandable graphite samples and averaging the maximum dimensions. The minimum and maximum dimensions of the thermally expandable graphite described above can be measured, for example, using a field emission scanning electron microscope (FE-SEM).

[0027] <Flexibility-imparting agent> The fire-resistant material of the present invention contains a flexibility-imparting agent. By including a flexibility-imparting agent, flexibility is imparted to the fire-resistant material, reducing the viscosity of the components of the fire-resistant material and making it less likely for the thermally expandable graphite to be crushed during the manufacture of the fire-resistant material. This allows the occluded expansion ratio to be set above a certain level, enabling expansion according to the shape of the space in which the fire-resistant material is placed. Furthermore, shrinkage of the fire-resistant material is less likely to occur even after molding, so the shape of the fire-resistant material can be stably maintained. In addition, tackiness is also imparted to the fire-resistant material, resulting in a fire-resistant material with excellent workability. Specifically, the flexibility-imparting agent is preferably at least one selected from plasticizers, rubber processing oils, liquid rubber, and liquid resins.

[0028] (Plasticizer) It is preferable that the plasticizer be a non-phthalate plasticizer. Using a non-phthalate plasticizer can reduce the environmental impact. Non-phthalate plasticizers are plasticizers other than phthalate plasticizers, which consist of derivatives of phthalic acid (orthophthalic acid). Examples of non-phthalate plasticizers include trimellitic acid plasticizers, phosphate ester plasticizers, adipic acid plasticizers, sulfonic acid plasticizers, citric acid plasticizers, soybean oil plasticizers, cyclohexane dicarboxylate plasticizers, and terephthalic acid plasticizers. These plasticizers are typically liquid at 23°C.

[0029] Examples of phosphate ester plasticizers include triaryl phosphates such as triphenyl phosphate, tricresyl phosphate, benzyl diphenyl phosphate, cresyl diphenyl phosphate, dicresyl phenyl phosphate, propylphenyl diphenyl phosphate, dipropylphenyl phosphate, ethylphenyl diphenyl phosphate, diethylphenyl phosphate, triethylphenyl phosphate, tripropylphenyl phosphate, butylphenyl diphenyl phosphate, dibutylphenyl phosphate, and tributylphenyl phosphate; alkyl phosphates such as tributyl phosphate, ethyl dibutyl phosphate, trihexyl phosphate, tri(2-ethylhexyl) phosphate, tridecyl phosphate, trilauryl phosphate, trimiristyl phosphate, tripalmystyl phosphate, and tristearyl phosphate; ethyl diphenyl phosphate; and trioleyl phosphate.

[0030] Examples of adipic acid-based plasticizers include adipic acid ether esters such as di-2-ethylhexyl adipate, diisononyl adipate, diisodecyl adipate, and dibutoxyethoxyethyl adipate. Examples of sulfonic acid-based plasticizers include benzenesulfonbutylamide, o-toluenesulfonamide, p-toluenesulfonamide, N-ethyl-p-toluenesulfonamide, o-tolueneethylsulfonamide, p-tolueneethylsulfonamide, N-cyclohexyl-p-toluenesulfonamide, alkyl sulfonic acid esters of phenol and cresol, sulfonamide-formamide, and alkyl sulfonic acid esters.

[0031] (Rubber processing oil) The rubber processing oil is not particularly limited, but any oil commonly used as a lubricant can be used. By including a rubber processing oil, the fluidity of the matrix components is improved, and the thermally expandable graphite is properly dispersed in the composition. As a result, the thermal expandability and residue strength of the refractory material are improved, and the refractory properties of the refractory material are enhanced. The rubber processing oil used in the present invention is not particularly limited, but examples include process oils. The process oil is not particularly limited and examples include paraffinic process oils, naphthenic process oils, and olefinic process oils. Among these, it is preferable to include naphthenic process oil. Furthermore, the kinematic viscosity of the rubber processing oil at 40°C is preferably 5 to 500 cSt, more preferably 10 to 450 cSt, and even more preferably 20 to 400 cSt. The kinematic viscosity can be measured in accordance with JIS K 2283.

[0032] (Liquid rubber) Liquid rubber is rubber that becomes liquid at 23°C. Examples of liquid rubber include liquid polyisoprene rubber, carboxy-modified liquid polyisoprene rubber, liquid polybutadiene rubber, carboxy-modified liquid polybutadiene rubber, hydroxyl-modified liquid polybutadiene rubber, liquid acrylonitrile butadiene copolymer rubber, liquid styrene butadiene copolymer rubber, and liquid styrene isoprene copolymer rubber. The number-average molecular weight (Mn) of the liquid rubber is preferably 1,000 to 150,000, and more preferably 10,000 to 100,000. The number-average molecular weight (Mn) of liquid rubber is a measurement obtained by converting it to standard polystyrene using a gel permeation chromatography analyzer. Furthermore, the viscosity of the liquid rubber at 38°C is preferably 5 to 1000 Pa·s, more preferably 50 to 800 Pa·s, and even more preferably 100 to 500 Pa·s.

[0033] (Liquid resin) Liquid resins are resins that become liquid at 23°C. Examples of liquid resins include polyvinyl acetate (PVAc) resins, silicone resins, modified silicone (MS) resins, polyisobutylene (PIB) resins, polysulfide resins, modified polysulfide resins, polyurethane resins, polyacrylic resins, and polyacrylic urethane resins. Among these, polyvinyl acetate resins are preferred.

[0034] In the present invention, the flexibility imparter may be used alone or in combination of two or more types. Among the above, it is preferable to use a plasticizer as the flexibility imparterer. Using a plasticizer can also suppress the bleeding of the flexibility imparterer to the surface of the refractory material. Among plasticizers, at least one selected from phosphate ester plasticizers, adipic acid plasticizers, and sulfonic acid plasticizers is preferred, the use of a sulfonic acid plasticizer is more preferred, and the use of an alkyl sulfonic acid ester is even more preferred.

[0035] The content of the flexibility-imparting agent is preferably 20 to 120 parts by mass, more preferably 25 to 110 parts by mass, even more preferably 30 to 80 parts by mass, and even more preferably 45 to 80 parts by mass, per 100 parts by mass of the matrix component. When the content of the flexibility-imparting agent is above the lower limit, the occlusion expansion ratio can be set to a certain level or higher, making the fire-resistant material more likely to expand in the event of a fire. Furthermore, when the content of the flexibility-imparting agent is below the upper limit, the residual strength of the fire-resistant material can be set to a certain level or higher, making it possible to form a fire-resistant material with excellent shape retention.

[0036] <Flame retardant> The fire-resistant material of the present invention preferably contains a flame retardant. By including a flame retardant, the flame retardancy of the fire-resistant material can be enhanced, and the performance of the fire-resistant material can be exhibited more effectively. The flame retardant used in the present invention is preferably solid at room temperature (23°C) and normal pressure (1 atm), and specifically includes phosphorus-based solid flame retardants, red phosphorus-based flame retardants, boron-containing flame retardants, bromine-based flame retardants, antimony-containing flame retardants, metal hydroxides, low-melting-point glass, needle-shaped fillers, and the like.

[0037] (Phosphorus-based solid flame retardant) Phosphorus-based solid flame retardants are solids that become solid at room temperature (23°C) and atmospheric pressure (1 atm), and are different from the red phosphorus-based flame retardants described later. Specifically, these include phosphates, phosphazene compounds, phosphate ester compounds, and phosphinate metal salts.

[0038] Specific examples of phosphates include monophosphates and polyphosphates. It should be noted that the term "phosphate" here includes not only orthophosphates but also phosphates and hypophosphates. The same applies to polyphosphates. Examples of monophosphates include ammonium salts such as ammonium phosphate, ammonium dihydrogen phosphate, and diammonium hydrogen phosphate; sodium salts such as monosodium phosphate, disodium phosphate, trisodium phosphate, monosodium phosphite, disodium phosphite, and sodium hypophosphite; potassium salts such as monopotassium phosphate, dipotassium phosphate, tripotassium phosphate, monopotassium phosphite, dipotassium phosphite, and potassium hypophosphite; lithium salts such as monolithium phosphate, dilithium phosphate, trilithium phosphate, monolithium phosphite, dilithium phosphite, and lithium hypophosphite; barium salts such as barium dihydrogen phosphate, barium hydrogen phosphate, tribarium phosphate, and barium hypophosphite; magnesium salts such as magnesium monohydrogen phosphate, magnesium hydrogen phosphate, trimagnesium phosphate, and magnesium hypophosphite; calcium salts such as calcium dihydrogen phosphate, calcium hydrogen phosphate, tricalcium phosphate, and calcium hypophosphite; zinc salts such as zinc phosphate, zinc phosphite, and zinc hypophosphite; and aluminum salts such as monoaluminum phosphate, dialuminum phosphate, trialuminum phosphate, and aluminum hypophosphite. Among these, ammonium phosphate and aluminum phosphite are preferred, and aluminum phosphite is more preferred. Examples of polyphosphates include ammonium polyphosphate, piperazine polyphosphate, melamine polyphosphate, ammonium polyphosphate amide, and aluminum polyphosphate, with ammonium polyphosphate being preferred among these.

[0039] Intomessent flame retardants can also be used as phosphates. Examples of intomessent flame retardants include phosphates containing a phosphorus-based component that promotes carbonization and a nitrogen-based component that promotes fire extinguishing and foaming. When combustion begins and the material heats up, intomessent flame retardants produce bubbles on the material surface, creating a foamy, insulating expansion layer that prevents heat from the material surface from transferring to the interior. At the same time, they suppress thermal decomposition and oxidation reactions by cutting off the supply of oxygen, thus fulfilling their role as flame retardants.

[0040] Phosphorus-based components that make up intomessent flame retardants include, for example, polyphosphates such as pyrophosphate and triphosphate, and monophosphates such as orthophosphate (orthophosphate).

[0041] Examples of nitrogen-based components constituting intomescent flame retardants include N,N,N',N'-tetramethyldiaminomethane, ethylenediamine, N,N'-dimethylethylenediamine, N,N'-diethylethylenediamine, N,N-dimethylethylenediamine, N,N-diethylethylenediamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetraethylethylenediamine, 1,2-propanediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane and 1,10-diaminodecane, aliphatic diamines, piperazine, trans-2,5-dimethylpiperazine, 1,4-bis(2-aminoethyl)piperazine, 1, Examples include amine compounds containing a piperazine ring, such as 4-bis(3-aminopropyl)piperazine, melamine, acetoguanamine, benzoguanamine, acrylicguanamine, 2,4-diamino-6-nonyl-1,3,5-triazine, 2,4-diamino-6-hydroxy-1,3,5-triazine, 2-amino-4,6-dihydroxy-1,3,5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4-diamino-6-ethoxy-1,3,5-triazine, 2,4-diamino-6-propoxy-1,3,5-triazine, 2,4-diamino-6-isopropoxy-1,3,5-triazine, 2,4-diamino-6-mercapto-1,3,5-triazine, and 2-amino-4,6-dimercapto-1,3,5-triazine, among others.

[0042] From the viewpoint of obtaining higher flame retardancy, it is preferable that the phosphorus-based component constituting the intomessent flame retardant contains polyphosphate.

[0043] The intomessent flame retardant is preferably at least one compound selected from the group consisting of melamine orthophosphate, melamine pyrophosphate, melamine polyphosphate, piperazine orthophosphate, piperazine pyrophosphate, and piperazine polyphosphate. In particular, a mixture of a melamine salt selected from the group consisting of melamine orthophosphate, melamine pyrophosphate, and melamine polyphosphate, and a piperazine salt selected from the group consisting of piperazine orthophosphate, piperazine pyrophosphate, and piperazine polyphosphate is more preferable. Furthermore, among the melamine salts, melamine pyrophosphate is more preferred from the viewpoint of flame retardancy, and among the piperazine salts, piperazine pyrophosphate is more preferred from the viewpoint of flame retardancy.

[0044] Phosphazene compounds are organic compounds in which phosphorus atoms and nitrogen atoms are alternately bonded. Examples of phosphazene compounds include cyclic phosphazene compounds, linear phosphazene compounds, and crosslinked phosphazene compounds crosslinked with crosslinking groups. Specifically, phosphazene compounds include those containing the constituent unit shown in the following general formula (1).

[0045] [ka] In the above general formula (1), X independently represents one of the following: an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 12 carbon atoms, an amino group, or a halogen atom. In general formula (1), examples of substituents on the aryl group include alkyl groups, amino groups, and halogen atoms. X is preferably independently a phenyl group, a substituted phenyl group, a phenyloxy group, or a substituted phenyl noble, and more preferably a phenyl group or a phenyloxy group.

[0046] The phosphate ester compound is not particularly limited as long as it is solid at room temperature (23°C), and examples include monophosphate esters and condensed phosphate esters. These phosphate ester compounds may be commercially available products. Examples of monophosphate esters include triphenyl phosphate and tris(tribromoneopentyl) phosphate. Commercially available monophosphate esters include "TPP," "CR-900," and "DAIGUARD-1000" (all manufactured by Daihachi Chemical Industry Co., Ltd.). The condensed phosphate ester may be a halogen-containing condensed phosphate ester, or a halogen-free condensed phosphate ester. More specifically, examples include alkyl-substituted aromatic condensed phosphate esters such as 1,3-phenylenebis(di-2,6-xylenyl phosphate). Commercially available condensed phosphate esters can also be used. Specifically, examples include halogen-free condensed phosphate esters such as "DAIGUARD-850" and "PX200" (both manufactured by Daihachi Chemical Industry Co., Ltd.).

[0047] A metal phosphinate salt is a metal salt of an organic phosphinic acid. Specific examples of metal phosphinate salts include, for example, aluminum tris-diethylphosphinate, aluminum tris-methylethylphosphinate, aluminum tris-diphenylphosphinate, zinc bis-diethylphosphinate, zinc bis-methylethylphosphinate, zinc bis-diphenylphosphinate, titanyl bis-diethylphosphinate, titanium tetrakis-diethylphosphinate, titanium bis-methylethylphosphinate, titanium tetrakis-methylethylphosphinate, titanium bis-diphenylphosphinate, and titanium tetrakis-diphenylphosphinate. Among these, aluminum tris-diethylphosphinate is preferred.

[0048] Furthermore, from the viewpoint of sufficiently enhancing the flame retardancy of the fire-resistant material, the phosphorus concentration in the phosphorus-based solid flame retardant is preferably 10% by mass or more, more preferably 12% by mass or more, and even more preferably 25% by mass or more, based on the total amount of the phosphorus-based solid flame retardant.

[0049] (Red phosphorus-based flame retardant) Red phosphorus-based flame retardants may consist of pure red phosphorus, but they may also be coated with a resin, metal hydroxide, metal oxide, etc., or they may be a mixture of red phosphorus and a resin, metal hydroxide, metal oxide, etc. The resin used to coat or mix with red phosphorus is not particularly limited, but examples include thermosetting resins such as phenolic resins, epoxy resins, unsaturated polyester resins, melamine resins, urea resins, aniline resins, and silicone resins. From the viewpoint of flame retardancy, metal hydroxides are preferred as the compound used for coating or mixing. The metal hydroxides described later may be appropriately selected and used.

[0050] (Boron-containing flame retardant) Examples of boron-containing flame retardants used in the present invention include borax, boron oxide, boric acid, and borates. Examples of boron oxides include diboron trioxide, boron trioxide, diboron dioxide, tetraboron trioxide, and tetraboron pentoxide. Examples of borates include alkali metals, alkaline earth metals, elements from groups 4, 12, and 13 of the periodic table, and ammonium borates. Specifically, examples include alkali metal borates such as lithium borate, sodium borate, potassium borate, and cesium borate; alkaline earth metal borates such as magnesium borate, calcium borate, and barium borate; zirconium borate, zinc borate, aluminum borate, and ammonium borate.

[0051] (Bromine-based flame retardant) Brominated flame retardants are not particularly limited as long as they contain bromine in their molecular structure and are solid at room temperature and atmospheric pressure, but examples include aromatic compounds containing brominated aromatic rings. Examples of aromatic compounds containing brominated aromatic rings include monomer-based organic brominated compounds such as hexabromobenzene, pentabromotoluene, hexabromobiphenyl, decabromobiphenyl, decabromodiphenyl ether, octabromodiphenyl ether, hexabromodiphenyl ether, bis(pentabromophenoxy)ethane, ethylenebis(pentabromophenyl), ethylenebis(tetrabromophthalimide), and tetrabromobisphenol A.

[0052] Furthermore, the brominated aromatic ring-containing aromatic compound may also be a brominated polymer. Specifically, examples include polycarbonate oligomers produced using brominated bisphenol A as a raw material, brominated polycarbonates such as copolymers of this polycarbonate oligomer and bisphenol A, and diexo compounds produced by the reaction of brominated bisphenol A and epichlorohydrin. In addition, examples include brominated epoxy compounds such as monoepoxy compounds obtained by the reaction of brominated phenols and epichlorohydrin, poly(brominated benzyl acrylate), brominated polyphenylene ether, brominated bisphenol A and cyanuryl chloride condensates, brominated polystyrene such as brominated (polystyrene), poly(brominated styrene), and crosslinked brominated polystyrene, and crosslinked or non-crosslinked brominated poly(methylstyrene). Furthermore, compounds other than brominated aromatic ring-containing aromatic compounds such as hexabromocyclododecane may also be used.

[0053] (Antimony-containing flame retardant) Examples of antimony-containing flame retardants include antimony oxide, antimonate salts, and pyroantimonate salts. Examples of antimony oxide include antimony trioxide and antimony pentoxide. Examples of antimonate salts include sodium antimonate and potassium antimonate. Examples of pyroantimonate salts include sodium pyroantimonate and potassium pyroantimonate.

[0054] (metal hydroxide) Examples of metal hydroxides used in the present invention include magnesium hydroxide, calcium hydroxide, aluminum hydroxide, iron hydroxide, nickel hydroxide, zirconium hydroxide, titanium hydroxide, zinc hydroxide, copper hydroxide, vanadium hydroxide, and tin hydroxide.

[0055] (Low melting point glass) Low-melting-point glass used as a solid flame retardant softens and melts when heated, acting as an inorganic binder and improving the mechanical strength of the refractory material. Specifically, low-melting-point glass refers to glass that softens or melts at temperatures below 1000°C, with a preferred softening temperature of 200-900°C, more preferably 300-800°C, and even more preferably 300-600°C. The softening temperature is measured, for example, from the inflection point of the DTA.

[0056] Examples of low-melting-point glasses include glasses composed of at least one element selected from the group consisting of silicon, aluminum, boron, phosphorus, zinc, iron, copper, titanium, vanadium, zirconium, tungsten, molybdenum, thallium, antimony, tin, cadmium, arsenic, lead, alkali metals, alkaline earth metals, halogens, and chalcogens, along with oxygen. Low-melting-point glasses may be in particulate form, such as glass frit. Examples of commercially available low-melting-point glasses include "4020" (aluminum phosphate-based low-melting-point glass, softening temperature: 380°C) manufactured by Nippon Horo Yuyaku Co., Ltd., "4706" (borosilicate-based low-melting-point glass, softening temperature: 610°C) manufactured by Nippon Horo Yuyaku Co., Ltd., and "FF209" (lithium borate-based low-melting-point glass, softening temperature: 450°C) manufactured by Asahi Techno Glass Co., Ltd.

[0057] (Needle-shaped filler) Examples of needle-shaped fillers include potassium titanate whiskers, aluminum borate whiskers, magnesium-containing whiskers, silicon-containing whiskers, wollastonite, sepiolite, zonolite, elestadite, boehmite, rod-shaped hydroxyapatite, glass fibers, carbon fibers, graphite fibers, metal fibers, slag fibers, gypsum fibers, silica fibers, alumina fibers, silica-alumina fibers, zirconia fibers, boron nitride fibers, boron fibers, and stainless steel fibers. The use of needle-shaped fillers can effectively improve the mechanical properties of refractory materials. These needle-shaped fillers can be used individually or in combination of two or more types. The aspect ratio (length / diameter) of the needle-shaped filler used in the present invention is preferably in the range of 5 to 50, and more preferably in the range of 10 to 40. This aspect ratio can be determined by observing the needle-shaped filler with a scanning electron microscope and measuring its length and width. These flame retardants may be used individually or in combination of two or more types.

[0058] In the present invention, from the viewpoint of sufficiently and effectively imparting flame retardancy to the fire-resistant material, phosphorus-based solid flame retardants are preferred as the flame retardant, phosphate salts are more preferred, and aluminum phosphite is even more preferred. While the use of phosphorus-containing compounds as flame retardants is preferred as described above, a low content of phosphorus-containing compounds is also preferred. Specifically, in a fire-resistant material, the content of phosphorus-containing compounds is preferably 1 part by mass or less per 100 parts by mass of the matrix component, and it is more preferable that the fire-resistant material does not contain phosphorus-containing compounds. The term "phosphorus-containing compound" as used herein refers to a general term for compounds containing phosphorus, and includes the phosphorus-based solid flame retardants, red phosphorus-based flame retardants, and low-melting-point glass containing phosphorus mentioned above.

[0059] The amount of flame retardant in the present invention is not particularly limited, but is preferably 20 to 100 parts by mass, more preferably 30 to 90 parts by mass, and even more preferably 40 to 80 parts by mass, per 100 parts by mass of matrix component. By having a flame retardant content above the lower limit, flame retardancy can be effectively imparted to the fire-resistant material. Furthermore, by having a flame retardant content below the upper limit, the proportion of other components in the fire-resistant material can be kept above a certain level, and the occlusion expansion ratio can be kept above a certain level.

[0060] Furthermore, inorganic fillers other than the solid flame retardants mentioned above may be used. Such inorganic fillers may include alumina, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, ferrites, basic magnesium carbonate, calcium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, dawsonite, hydrotalcite, calcium sulfate, barium sulfate, calcium silicate, talc, mica, montmorillonite, bentonite, activated clay, imogolite, sericite, glass beads, aluminum nitride, boron nitride, silicon nitride, various metal powders, magnesium sulfate, lead zirconate titanate, molybdenum sulfide, silicon carbide, various magnetic powders, fly ash, etc. These inorganic fillers may be used individually or in combination of two or more. Among the inorganic fillers listed above, calcium carbonate is preferred. When using inorganic fillers, their content is not particularly limited, but is preferably 1 to 200 parts by mass, more preferably 10 to 100 parts by mass, and even more preferably 15 to 60 parts by mass, per 100 parts by mass of the matrix component.

[0061] <Crosslinking agent> The fire-resistant material of the present invention may contain a crosslinking agent, and in particular when acrylonitrile-butadiene rubber is used as the rubber component, the expansion pressure can be increased by using a crosslinking agent in combination, thereby improving fire resistance. When a fire-resistant material contains a crosslinking agent, it is thought that the heat during a fire promotes the crosslinking of matrix components such as the rubber component, increasing viscosity, and consequently increasing the expansion pressure.

[0062] Any known crosslinking agent can be used without limitation, including, for example, sulfur-based crosslinking agents, organic peroxides, and azo compounds. Sulfur-based crosslinking agents may be inorganic, such as sulfur, insoluble sulfur, precipitated sulfur, sulfur chloride, sulfur monochloride, or sulfur dichloride, but sulfur-containing organic crosslinking agents may also be used. Examples of sulfur-containing organic crosslinking agents include morpholine disulfide, alkylphenol disulfide, N,N'-dithio-bis(hexahydro-2H-azepinone-2), thiuram polysulfide, and 2-(4'-morpholino-dithio)benzothiazole. Examples of organic peroxides include 2,5-dimethylhexane, 2,5-dihydroperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 3-di-t-butylperoxide, t-dicumylperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexine, dicumylperoxide, α,α'-bis(t-butylperoxyisopropyl)benzene, n-butyl-4,4-bis(t-butylperoxy)butane, 2,2-bis(t-butylperoxy)butane, 1,1-bis(t-butylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane, t-butylperoxybenzoate; benzoylperoxide; t-butylperoxy-2-ethylhexyl carbonate, etc. Examples of azo compounds include azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile). The crosslinking agent may be used alone or in combination of two or more types.

[0063] Furthermore, among the crosslinking agents mentioned above, those that do not readily undergo a crosslinking reaction at the mixing temperature (e.g., 70°C to 150°C) when manufacturing refractory materials, and that readily undergo a crosslinking reaction of rubber components such as acrylonitrile-butadiene rubber due to the heat during a fire, are preferred. Specifically, sulfur-based crosslinking agents are preferred, and among these, inorganic types are preferred from the viewpoint of crosslinking properties, with sulfur being more preferred. If the refractory material contains a crosslinking agent, the amount of the crosslinking agent is preferably 0.1 to 10 parts by mass, more preferably 0.2 to 5 parts by mass, and even more preferably 0.5 to 3 parts by mass, per 100 parts by mass of the matrix component.

[0064] <Crosslinking promoter> The fire-resistant material of the present invention may contain a crosslinking accelerator in addition to the crosslinking agent. Examples of crosslinking accelerators include metal oxides. Examples of metal oxides include zinc oxide and magnesium oxide. When using metal oxides in the present invention, zinc oxide is preferred. These metal oxides are more preferably used in combination with long-chain aliphatic carboxylic acids having 12 to 24 carbon atoms, preferably 16 to 20 carbon atoms, such as stearic acid. In this specification, the long-chain aliphatic carboxylic acids used in combination with metal oxides are also referred to as crosslinking accelerators. In addition to those mentioned above, other crosslinking accelerators that can be used in the refractory material of the present invention include, for example, thiazole compounds, sulfenamide compounds, thiuram compounds, dithiocarbamate compounds, and guanidine compounds. An example of a thiazole compound is bis(benzothiazole-2-ylthio)zinc. The crosslinking accelerator may be used alone or in combination of two or more types. As the crosslinking accelerator, at least one selected from metal oxides and thiazole compounds is preferred, and a combination of these is also preferred. In this case, the metal oxide may be further used in combination with a long-chain aliphatic carboxylic acid having 16 to 20 carbon atoms, such as stearic acid.

[0065] In the fire-resistant material of the present invention, the amount of crosslinking accelerator used is not particularly limited, but is preferably 0.1 to 15 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 1 to 8 parts by mass, per 100 parts by mass of the matrix component.

[0066] <Other additives> The fire-resistant material of the present invention may contain various additive components as needed, as long as the objective of the present invention is not impaired. The type of additive component is not particularly limited, and various additives can be used. Examples of such additives include shrinkage inhibitors, nucleating agents, colorants (pigments, dyes, etc.), UV absorbers, antioxidants, anti-aging agents, dispersants, gelling accelerators, fillers, reinforcing agents, flame retardant aids, antistatic agents, surfactants, and surface treatment agents. The amount of additive added can be appropriately selected within a range that does not impair moldability, etc. Additives may be used individually or in combination of two or more types.

[0067] <Mooney viscosity of fire-resistant material> The fire-resistant material of the present invention preferably has a Mooney viscosity of 80 or less at 100°C. A Mooney viscosity of 80 or less allows the occlusion expansion ratio of the fire-resistant material to be above a certain level, making it easier for the fire-resistant material to expand in the planar direction during a fire. From this perspective, the Mooney viscosity is more preferably 75 or less, and even more preferably 70 or less. On the other hand, the lower limit of the Mooney viscosity is not particularly limited, but from the viewpoint of ensuring a certain degree of shape retention of the fire-resistant material, it is preferably 5 or more, more preferably 20 or more, and even more preferably 35 or more. The Mooney viscosity of the refractory material mentioned above is a value measured before the refractory material undergoes thermal expansion, and the measurement method is the same as for rubber, in accordance with JIS K6300.

[0068] <Residue strength> The fire-resistant material of the present invention preferably has a residual strength of 2N or more after thermal expansion, more preferably 5N or more, and even more preferably 7N or more. A residual strength of 5N or more after thermal expansion allows the fire-resistant material to effectively block flames and prevent the spread of fire during a fire. On the other hand, the upper limit of the residual strength after thermal expansion is not particularly limited, but from a practical standpoint, it is, for example, 20N or less, preferably 15N or less.

[0069] <thickness> The fire-resistant material of the present invention is preferably in sheet form, and its thickness is not particularly limited, but from the viewpoint of fire resistance and ease of handling, it is preferably 0.2 to 10 mm, and more preferably 0.5 to 3.0 mm.

[0070] <Method for manufacturing fire-resistant materials> The fire-resistant material of the present invention can be manufactured, for example, as described below. First, a matrix component, thermally expandable graphite, resin, plasticizer, flame retardant, crosslinking agent (if necessary), and other components are mixed in a mixer such as a kneading roll to obtain a fire-resistant resin composition. Next, the obtained fire-resistant resin composition can be molded into a sheet or the like by known molding methods such as press molding, calendering, or extrusion molding to obtain a fire-resistant material. Alternatively, the fire-resistant resin composition may be applied to a support substrate such as a release sheet or resin film to form a sheet. The support substrate can be peeled off from the fire-resistant material obtained in sheet form as appropriate. Furthermore, the fire-resistant resin composition may be heated as appropriate after or while being formed into a sheet, and if a thermosetting resin is used, the fire-resistant resin composition may be cured by such heating. The mixing temperature and the temperature at which the material is formed into a sheet are preferably below the expansion initiation temperature of the thermally expandable graphite. If a crosslinking agent is included, the temperature should be such that the crosslinking agent is less likely to crosslink. Therefore, the mixing temperature is preferably 70 to 150°C, and more preferably 90 to 140°C. The temperature at which the material is formed into a sheet is preferably 80 to 130°C, and more preferably 90 to 120°C.

[0071] <Laminated sheet> The fire-resistant material of the present invention may be laminated with other sheet members or adhesive layers to form a laminated sheet. The laminated sheet comprises, for example, a base material and a fire-resistant material laminated on one or both sides of the base material. The base material is usually a woven or nonwoven fabric. The fibers used in the woven or nonwoven fabric are not particularly limited, but non-combustible or semi-non-combustible materials are preferred, such as glass fibers, ceramic fibers, cellulose fibers, polyester fibers, carbon fibers, graphite fibers, thermosetting resin fibers, etc. The laminated sheet described above can be obtained, for example, by forming a fire-resistant resin composition into a sheet on a substrate.

[0072] Furthermore, the laminated sheet may comprise a fire-resistant material and an adhesive layer. The adhesive layer may be laminated, for example, on one or both sides of the fire-resistant material. Furthermore, the laminated sheet may comprise a fire-resistant material, a base material, and an adhesive layer. In such a laminated sheet, the fire-resistant material may be provided on one side of the base material and the adhesive layer on the other side, or the fire-resistant material and the adhesive layer may be provided on one side of the base material in this order. The adhesive layer can be formed, for example, by transferring an adhesive coated on release paper to the laminated sheet.

[0073] The fire-resistant material of the present invention, and the laminated sheet using the same, can be used in various types of building components such as detached houses, apartment buildings, high-rise buildings, commercial facilities, and public facilities, as well as various vehicles such as automobiles and trains, ships, and aircraft. Among these, its use in building components is preferred. Specifically, it can be used in walls, beams, columns, floors, bricks, roofs, boards, windows, shoji screens, doors, sliding doors, transoms, wiring, and piping, but is not limited to these. The fire-resistant material of the present invention, and the laminated sheet using the same, can be applied in particular to gaps in building components such as windows, doors, and sliding doors to prevent flames from passing through and entering during a fire. [Examples]

[0074] The present invention will be described in more detail below using examples, but the present invention is not limited to these examples.

[0075] [Evaluation Method] The methods for measuring and evaluating the various physical properties of thermally expandable fire-resistant materials are as follows:

[0076] The above evaluations were performed using the thermally expandable fire-resistant materials obtained in each example and comparative example. The evaluation results for each item are shown in Table 1.

[0077] <Mooney viscosity at 100°C> Mooney viscosity ML(1+4) was measured in accordance with JIS K6300.

[0078] <Occlusion expansion ratio> The refractory material prepared in each example and comparative example was cut into a rectangular parallelepiped measuring 25 mm x 25 mm x 2 mm. Then, as shown in Figure 1, the refractory material 10 was placed in a space 12 with a height h of 6 mm within a jig 11 made of SUS plates measuring 100 mm x 100 mm at the top and bottom. The refractory material 10, along with the jig 11, was then placed in an oven preheated to 400°C and heated for 15 minutes. After heating as described above, the occlusion expansion ratio is calculated using the following formula based on the area of ​​the fire-resistant material viewed from the thickness direction. I calculated it. Boundary expansion ratio (times) = Area after heating (mm²) 2 (Area of ​​fire-resistant material shown in Figure 2, right diagram) / Area before heating (mm²) 2 (The area of ​​the fire-resistant material shown in Figure 2, left diagram) Based on the occlusion expansion ratio calculated using the method described above, an evaluation of the occlusion expansion ratio was conducted. The evaluation criteria are as follows. AA: 8 times or more A: 4.0 times or more but less than 8 times C: Less than 4.0x

[0079] <Residue strength> The residual strength of the refractory material was measured according to the following procedure (1) to (3). (1) The fire-resistant materials prepared in each example and comparative example were cut into rectangular parallelepipeds measuring 20 mm × 100 mm × 2 mm. (2) As shown in Figure 3, the fire-resistant material 10 was placed inside a U-shaped jig (material: steel) 15 with a height t of 6 mm, and the fire-resistant material 10, along with the U-shaped jig 15, was placed in an oven that had been preheated to 600°C, and the fire-resistant material 10 was heated for 20 minutes. (3) After heating, the portion of the refractory material 10 that protruded from the U-shaped jig 15 was removed, and then the refractory material 10 was removed from the U-shaped jig 15. As shown in Figure 4, the refractory material 10 was placed on two stands 17 spaced 25 mm apart from each other, with its longitudinal direction aligned with the transverse direction in Figure 4, and a three-point bending test was performed by pressing a load jig 16 made of a 10 mm x 10 mm SUS plate against the refractory material 10. The maximum point load in this test was defined as the residual strength. The residue strength obtained as described above was evaluated. The evaluation criteria are as follows: A: 5N or higher B: 2N or more, less than 5N C: Less than 2N

[0080] [Materials used] The following materials were used in each example and comparative example.

[0081] <Thermally expandable graphite> • Thermally expandable graphite, ADT351 manufactured by ADT Corporation

[0082] <Matrix Components> 1. Rubber • Rubber A: NBR, manufactured by Zeon Corporation, "DN401L", Nitrile content: 18% • Rubber B: BR JSR Corporation "BR-01" • Rubber C: SBR JSR "SBR1502" • Rubber D: IIR JSR "BUTYL065" • Rubber E: EPDM, manufactured by Mitsui Chemicals, "EPT X-4010M"

[0083] 2. Resin • Resin A: EVA, manufactured by Mitsui Dow Polychemicals, "EV170" • Resin B: PVC, manufactured by Shin-Etsu Chemical Co., Ltd., "TK1000" • Resin C: Epoxy resin. Main component: Mitsubishi Chemical Corporation "E-807", Hardener: Mitsubishi Chemical Corporation "SA1", Main component: Hardener (mass ratio) = 100:60 • Resin D: PMMA, manufactured by Mitsubishi Chemical Corporation, "Acrypet VH"

[0084] <Flame retardant> • Aluminum phosphite manufactured by Taihei Chemical Industry Co., Ltd. ("NSF")

[0085] <Inorganic fillers> Calcium carbonate

[0086] <Plasticizer> • Plasticizer A: Alkyl sulfonic acid ester, manufactured by Lanxess Corporation, "Mezamol" • Plasticizer B: Dibutoxyethoxyethyl adipate (ADEKA Corporation, "ADEKA Sizer RS-107") • Plasticizer C: Tricresyl phosphate, manufactured by Daihachi Chemical Industry Co., Ltd., "TCP" • Plasticizer D: Triaryl phosphate, manufactured by Ajinomoto Fine Techno Co., Ltd., "Rheophos 65"

[0087] <Rubber processing oil> Lubricant A: Naphthenic process oil 1, "Sansen 410" manufactured by Nippon Sun Oil Co., Ltd., kinematic viscosity 20.8 cSt Lubricant B: Naphthenic process oil 2, "Sansen 4240" manufactured by Nippon Sun Oil Co., Ltd., kinematic viscosity 374 cSt

[0088] <Liquid rubber> • Liquid rubber A: Liquid NBR "Nipol 1312" manufactured by Nippon Zeon Co., Ltd. • Liquid rubber B: Liquid BR manufactured by Nippon Soda Co., Ltd. "TD3000" <Liquid resin> • Liquid resin A: PVAc, manufactured by Kanto Chemical Co., Ltd., "Vinyl Acetate (polymer) Solution"

[0089] [Examples 1-18, 20-23, Comparative Examples 1-2] A refractory resin composition was obtained by adding the matrix components, thermally expandable graphite, flame retardant, and flexibility agent to a roll and kneading at 120°C for 5 minutes according to the formulation shown in Table 1. The obtained refractory resin composition was press-molded at 100°C for 3 minutes to obtain a 1.8 mm thick sheet of refractory material. The evaluation results are shown in Table 1.

[0090] [Example 19] According to the formulation shown in Table 1, the matrix component, thermally expandable graphite, flame retardant, and flexibility agent were supplied to a planetary agitator and kneaded at room temperature at 1000 rpm for 1 minute to obtain a refractory resin composition. Subsequently, the refractory resin composition was applied to a PET film and press-molded at 20°C at 10 MPa to obtain a sheet-like molded body with a thickness of 500 μm. The molded body was then cured in a constant temperature bath at 90°C for 10 hours to obtain a sheet-like refractory material. The evaluation results are shown in Table 1.

[0091] [Table 1]

[0092] As is clear from the above examples, it was confirmed that the thermally expandable fire-resistant material satisfying the requirements of the present invention expanded sufficiently in the planar direction even in a narrow space in the thickness direction. In contrast, when the heat-expandable fire-resistant material prepared in the comparative example was placed in a narrow space in the thickness direction, it could not be confirmed that it expanded sufficiently in the planar direction. [Explanation of Symbols]

[0093] 10 Thermally expandable fireproofing material 11. Fixture for placing fire-resistant materials 12 Space 13 Metal plate 14 Fixing member 15 U-shaped jig 16 Loading fixture 17 units h, t height

Claims

1. A heat-expandable fire-resistant material comprising at least one matrix component selected from the group consisting of rubber and resin, heat-expandable graphite, and a flexibility-imparting agent, Both the rubber and the resin are solid at 23°C. The flexibility imparter comprises a non-phthalate plasticizer, and the non-phthalate plasticizer is at least one selected from the group consisting of phosphate ester plasticizers, adipic acid plasticizers, and sulfonic acid plasticizers. A heat-expandable fire-resistant material, wherein when the heat-expandable fire-resistant material is cut to dimensions of 25 mm x 25 mm x 2 mm, placed in a space of 6 mm in the thickness direction, and then heated at 400°C for 15 minutes, the occluded expansion ratio obtained by dividing the area of ​​the heat-expandable fire-resistant material as viewed from the thickness direction by the area before heating is 4.0 times or more.

2. The heat-expandable fire-resistant material according to claim 1, wherein the heat-expandable fire-resistant material further contains a flame retardant.

3. The heat-expandable refractory material according to claim 1 or 2, wherein the content of the non-phthalate plasticizer is 20 to 120 parts by mass per 100 parts by mass of the matrix component.

4. The heat-expandable fire-resistant material according to claim 2, wherein the amount of the flame retardant is 20 to 100 parts by mass per 100 parts by mass of the matrix component.

5. The heat-expandable fire-resistant material according to claim 1 or 2, wherein the resin is one or more selected from the group consisting of ethylene-vinyl acetate copolymer resin, polyvinyl chloride resin, epoxy resin, and polymethyl methacrylate resin.

6. The heat-expandable fire-resistant material according to claim 1 or 2, wherein the heat-expandable fire-resistant material further contains an inorganic filler.

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