Thermally expandable refractory

Abstract

To provide a thermally expansible fireproof material which has such good expansion characteristics as to block a gap in the case of fire, and can follow deformation of fittings.SOLUTION: A thermally expansible fireproof material has an expansion layer containing a binder resin and a thermally expansible graphite, and has an expansion magnification of three times or more, and a maximum shear load of 20 N or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a heat-expandable fire-resistant material containing heat-expandable graphite. [Background technology]

[0002] In the field of construction, fire-resistant materials are used in building materials such as doors, windows, columns, and wall materials for fire prevention. As fire-resistant materials, thermally expandable fire-resistant materials are used, which are resins into which flame retardants, inorganic fillers, and thermally expandable graphite are compounded (see, for example, Patent Document 1). Such thermally expandable fire-resistant materials expand when heated, and the combustion residue forms a fire-resistant and heat-insulating layer, exhibiting fire-resistant and heat-insulating performance. A heat-expandable fire-resistant material containing heat-expandable graphite can be installed, for example, in gaps in building components such as doors and sashes (for example, the gap between a door and a door frame) in the openings of a building. In the event of a fire, the sheet expands in the thickness direction, sealing the gap and preventing the spread of fire. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2013-130005 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, even if a heat-expandable fire-resistant material containing heat-expandable graphite has good expansion properties that allow it to seal gaps during a fire, there was a problem in that the fire-resistant material could peel off because it could not follow the deformation of building components such as door frames, creating voids and reducing its fire resistance. Therefore, the present invention aims to provide a heat-expandable fire-resistant material that has good expansion characteristics that can seal gaps in the event of a fire and can follow the deformation of building components. [Means for solving the problem]

[0005] As a result of diligent research to solve the above problems, the inventors have found that the above problems can be solved by a thermally expandable fire-resistant material comprising an expansion layer containing a binder resin and thermally expandable graphite, wherein the expansion ratio and maximum shear load measured under specific conditions are above a certain level, and have completed the present invention. In other words, the present invention relates to the following [1] to [7]. [1] A heat-expandable fire-resistant material comprising an expansion layer containing a binder resin and heat-expandable graphite, wherein the expansion ratio in the thickness direction when the heat-expandable fire-resistant material is cut to dimensions of 50 mm × 50 mm and heated at 400°C for 20 minutes is 3 times or more, and the heat-expandable fire-resistant material is cut to dimensions of 25 mm × 25 mm, and the heat-expandable fire-resistant material is attached to the surface of one of two SUS plates which are placed facing each other at a distance of 3 times the thickness of the expansion layer of the heat-expandable fire-resistant material and with a facing area of ​​50 mm × 50 mm, and the shear load measurement sample obtained by heating at 400°C for 20 minutes has a maximum shear load of 20 N or more when measured under tensile conditions of 1 mm / min. [2] The heat-expandable fire-resistant material according to [1] above, wherein the binder resin contains a rubber component. [3] The heat-expandable fire-resistant material according to [1] or [2] above, wherein the binder resin does not contain halogens in its molecular structure. [4] The heat-expandable fire-resistant material according to any one of [1] to [3] above, wherein the binder resin contains a nitrile group. [5] A heat-expandable fire-resistant material according to any of [1] to [4] above, comprising a surface material that does not contain heat-expandable graphite. [6] The heat-expandable fire-resistant material according to [5] above, wherein the binder resin contained in the surface material does not contain halogens in its molecular structure. [7] A heat-expandable fire-resistant material as described in any of [1] to [6] above, used as a fire-resistant component for fire doors and sashes. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a heat-expandable fire-resistant material that has good expansion characteristics that can seal gaps in the event of a fire and can follow the deformation of building components. [Brief explanation of the drawing]

[0007] [Figure 1] This is a diagram illustrating the method for measuring the maximum shear load. [Figure 2] This is a diagram illustrating the method for measuring the maximum shear load. [Modes for carrying out the invention]

[0008] [Thermally expandable fireproof material] The heat-expandable fire-resistant material of the present invention comprises an expansion layer containing a binder resin and heat-expandable graphite, wherein the expansion ratio in the thickness direction when the heat-expandable fire-resistant material is cut to dimensions of 50 mm × 50 mm and heated at 400°C for 20 minutes is 3 times or more, and the maximum shear load is 20 N or more. The maximum shear load is measured as follows: The heat-expandable fire-resistant material is cut to dimensions of 25 mm × 25 mm, and attached to the surface of one of two SUS plates that are placed facing each other at a distance of 3 times the thickness of the expansion layer and with a facing area of ​​50 mm × 50 mm between the SUS plates, and heated at 400°C for 20 minutes to obtain a shear load measurement sample. The maximum shear load is measured by measuring the shear load measurement sample under a tensile condition of 1 mm / min. Hereinafter, the heat-expandable fire-resistant material of the present invention may be simply referred to as fire-resistant material. The fire-resistant material may be in sheet form and may consist only of an expansion layer, or, as described later, may also include a surface layer and an adhesive layer in addition to the expansion layer.

[0009] (Expansion ratio) The expansion ratio of the fire-resistant material of this invention is 3 times or more. If the expansion ratio of the fire-resistant material is less than 3 times, it will be difficult to seal gaps in building components during a fire, making it difficult to prevent the spread of fire. The expansion ratio of the fire-resistant material of the present invention is preferably 5 times or more, more preferably 10 times or more, from the viewpoint of easily sealing gaps. Furthermore, from the viewpoint of conforming to building components during a fire, the expansion ratio of the thermally expandable fire-resistant material of the present invention is preferably 15 times or less, more preferably 12 times or less.

[0010] The expansion ratio of the refractory of the present invention is the expansion ratio in the thickness direction when the refractory cut into a size (width × length) of 50 mm × 50 mm is heated at 400°C for 20 minutes, and can be obtained by dividing the thickness of the refractory after heating by the thickness of the refractory before heating. The expansion ratio can be adjusted by the type and amount of thermally expandable graphite, binder resin, and plasticizer blended as required.

[0011] (Maximum shear load) The maximum shear load of the refractory of the present invention is 20 N or more. If the maximum shear load is less than 20 N, it becomes difficult for the refractory expanded during a fire to follow the deformation of the furniture, and the fire resistance decreases. From the viewpoint of improving fire resistance, the maximum shear load of the refractory is preferably 30 N or more, more preferably 50 N or more. The upper limit value of the maximum shear load of the refractory is not particularly limited, but is, for example, 200 N. The maximum shear load can be adjusted to a desired value by adjusting the type and amount of the binder resin, thermally expandable graphite, and plasticizer blended as required contained in the refractory.

[0012] The method for measuring the maximum shear load of the refractory of the present invention will be described using the drawings. First, the refractory is cut into a size (width × length) of 25 mm × 25 mm, and a refractory 13 as a sample for measuring the maximum shear load is prepared. Next, two SUS plates (stainless steel plates) 11 and 12 are prepared. The two SUS plates 11 and 12 are arranged so as to face each other at an interval three times the thickness t of the refractory 13. That is, the interval L between the SUS plate 11 and the SUS plate 12 in FIG. 1 is three times the thickness t of the refractory 13. And, the area S where the SUS plates 11 and 12 face each other (that is, the region where the SUS plates overlap when viewed from the thickness direction) is arranged to be 50 mm × 50 mm. Although not shown, spacers are arranged between the SUS plates 11 and 12 so as to maintain the interval at L. Then, on the surface of the SUS plate 11 facing the SUS plate 12, the refractory material 13 cut into 25 mm × 25 mm as described above is pasted. When pasting the refractory material 13 on the surface of the SUS plate 11, it is pasted through an acrylic adhesive with a thickness of 200 μm. As the acrylic adhesive, 4965 manufactured by tesa may be used. In this way, a structure 14 having two SUS plates 11 and 12 and the refractory material 13 pasted on the surface of one of the two SUS plates is produced. Next, the structure 14 produced as described above is heated at 400 °C for 20 minutes. When heated, as shown in FIG. 2, the refractory material 13 expands and the space between the SUS plate 11 and the SUS plate 12 is blocked. In this way, a shear load measurement sample 15 is produced.

[0013] Using the shear load measurement sample 15 produced as described above, the maximum shear load is measured. The maximum shear load is measured by a tensile test that pulls the SUS plates 11 and 12 of the shear load measurement sample 15 in the shear direction. Specifically, a tensile test is performed by fixing the SUS plate 11 and pulling the SUS plate 12 at a speed of 1 mm / min. The tensile test is to be performed at 25 °C. And the maximum value of the shear load measured during the tensile test is taken as the maximum shear load. The larger the maximum shear load, the easier it is to follow the deformation of various members such as fittings, which means excellent fire resistance.

[0014] The refractory material of the present invention includes an expansion layer containing a binder resin and thermally expandable graphite. Hereinafter, the composition of the refractory material will be described.

[0015] (Binder resin) As the binder resin, for example, it contains at least one selected from resin and rubber components. Among them, the binder resin preferably contains a rubber component. Also, the binder resin preferably does not contain halogen in its molecular structure. By using a binder resin that does not contain halogen, corrosion of various members using the refractory material can be suppressed.

[0016] <Rubber components> Examples of rubber components include natural rubber, isoprene rubber, butyl rubber, butadiene rubber (BR), 1,2-polybutadiene rubber, styrene-butadiene rubber (SBR), chloroprene rubber, acrylonitrile-butadiene rubber (NBR), ethylene-propylene rubber, ethylene-propylene-diene rubber (EPDM), chlorosulfonated polyethylene, acrylic rubber, epichlorohydrin rubber, silicone rubber, fluororubber, and urethane elastomer. Among these, the rubber component is preferably at least one selected from the group consisting of styrene-butadiene rubber, acrylonitrile rubber-butadiene rubber, chloroprene rubber, and butadiene rubber, from the viewpoint of setting the expansion ratio and maximum shear load of the refractory material within the desired range described above. Furthermore, among these rubber components, those that do not contain halogens are preferred from the viewpoint of suppressing corrosion of various components using the refractory material, and the rubber component is preferably at least one selected from the group consisting of styrene-butadiene rubber, acrylonitrile rubber-butadiene rubber, and butadiene rubber.

[0017] Furthermore, it is preferable that the binder resin contains nitrile groups. Using a binder resin containing nitrile groups makes it easier to increase the residual strength after expansion of the refractory material, thereby improving its refractory properties. Examples of binder resins containing nitrile groups include homopolymers of acrylonitrile and copolymers of acrylonitrile with other compounds having ethylenically unsaturated bonds, with acrylonitrile-butadiene rubber being particularly preferred. The binder resin may be used alone or in combination of two or more types.

[0018] The nitrile content of the acrylonitrile-butadiene rubber is preferably 8 to 40% by mass, more preferably 10 to 35% by mass, and even more preferably 15 to 25% by mass. Fire-resistant materials containing acrylonitrile-butadiene rubber with a nitrile content within the above range have good flexibility, and when used in combination with a plasticizer described later, the flexibility can be further enhanced, making it easier to follow the deformation of components such as building fixtures. The Mooney viscosity ML(1+4) of acrylonitrile-butadiene rubber at 100°C is preferably 20 to 90, more preferably 25 to 80, and even more preferably 30 to 70. Fire-resistant materials containing acrylonitrile-butadiene rubber with a Mooney viscosity ML(1+4) at 100°C within the above range make it easier to ensure adhesion to various components such as building fixtures and improve conformability to those components. It is also preferable to use two or more types of acrylonitrile butadiene rubber with different Mooney viscosity ML(1+4) at 100°C in combination. In this case, the Mooney viscosity ML(1+4) of each acrylonitrile butadiene rubber at 100°C is preferably 20 to 90, more preferably 25 to 80, and even more preferably 30 to 70. In this specification, Mooney viscosity is measured in accordance with JIS K6300.

[0019] Chloroprene rubber can reduce the proportion of carbon contained in fire-resistant materials, and therefore, from the viewpoint of improving fire resistance, it is also preferable to use chloroprene rubber as the rubber included in fire-resistant materials. As for chloroprene rubber, sulfur-modified type (G type), non-sulfur-modified type (W type), etc., can also be used. The Mooney viscosity ML(1+4) of chloroprene rubber at 100°C is preferably 20 to 120, and more preferably 30 to 90, from the viewpoint of improving the conformability of the refractory material to the component.

[0020] Examples of styrene-butadiene rubber include random copolymers of styrene and butadiene. The amount of styrene 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. 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, from the viewpoint of improving the conformability of the refractory material to the component.

[0021] While there are no particular limitations on the butadiene rubber, from the viewpoint of improving the conformability of the refractory material to the components, the Mooney viscosity ML(1+4) at 100°C is preferably 20 to 60, and more preferably 30 to 55.

[0022] <Resin> The resin may be a thermosetting resin or a thermoplastic resin, but a thermoplastic resin is preferred. The thermoplastic resin is not particularly limited, but examples include polyolefin resins such as polypropylene resin and polyethylene resin, ethylene-vinyl acetate copolymer, polyvinyl acetate resin, polyvinyl chloride resin, fluororesins such as polytetrafluoroethylene, phenolic resin, polycarbonate resin, polyacrylonitrile resin, and urethane-based resins such as urethane elastomer.

[0023] The binder resin content in the expanded layer of the fire-resistant material is not particularly limited, but for example, it is 20 to 90% by mass, preferably 30 to 80% by mass, and more preferably 40 to 70% by mass, based on the total amount of the expanded layer.

[0024] (Thermally expandable graphite) The expansion layer in 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 a 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.

[0025] The content of thermally expandable graphite in the expansion layer is preferably 20 to 300 parts by mass, more preferably 30 to 150 parts by mass, and even more preferably 40 to 70 parts by mass, per 100 parts by mass of binder resin. If the content of thermally expandable graphite is above these lower limits, it becomes easier to increase the expansion pressure of the thermally expandable fire-resistant material, and it becomes easier to adjust the expansion ratio to a desired range. On the other hand, if the content of thermally expandable graphite is below these upper limits, it becomes easier to adjust the maximum shear load of the fire-resistant material to the desired value described above, and it becomes easier to improve the ability to follow the deformation of components such as building fixtures.

[0026] 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).

[0027] The average particle size of the thermally expandable graphite is preferably 50 to 500 μm, and more preferably 100 to 400 μm. 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).

[0028] (Flame retardant) The fire-resistant material of the present invention preferably contains a flame retardant. The inclusion of a flame retardant improves fire resistance. Examples of flame retardants include various phosphate esters such as triphenyl phosphate (triphenyl phosphate), tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, and xylenyl diphenyl phosphate; metal phosphate salts such as sodium phosphate, potassium phosphate, and magnesium phosphate; metal phosphate salts such as sodium phosphite, potassium phosphite, magnesium phosphite, and aluminum phosphite; ammonium polyphosphate; and red phosphorus. Other examples of flame retardants include compounds represented by the following general formula (1).

[0029] [ka]

[0030] In the above general formula (1), R 1 and R 3 R represents, either identically or differently, hydrogen, a linear or branched alkyl group having 1 to 16 carbon atoms, or an aryl group having 6 to 16 carbon atoms. 2 This represents a hydroxyl group, a linear or branched alkyl group having 1 to 16 carbon atoms, a linear or branched alkoxyl group having 1 to 16 carbon atoms, an aryl group having 6 to 16 carbon atoms, or an aryloxy group having 6 to 16 carbon atoms.

[0031] Specific examples of compounds represented by the general formula (1) include methylphosphonic acid, dimethyl methylphosphonate, diethyl methylphosphonate, ethylphosphonic acid, n-propylphosphonic acid, n-butylphosphonic acid, 2-methylpropylphosphonic acid, t-butylphosphonic acid, 2,3-dimethylbutylphosphonic acid, octylphosphonic acid, phenylphosphonic acid, dioctylphenylphosphonate, dimethylphosphinic acid, methylethylphosphinic acid, methylpropylphosphinic acid, diethylphosphinic acid, dioctylphosphinic acid, phenylphosphinic acid, diethylphenylphosphinic acid, diphenylphosphinic acid, bis(4-methoxyphenyl)phosphinic acid, and the like. The flame retardants may be used alone or in combination of two or more types.

[0032] Boron-based compounds and metal hydroxides can also be used as flame retardants in the present invention. Examples of boron-based compounds include zinc borate. Examples of metal hydroxides include aluminum hydroxide, magnesium hydroxide, calcium hydroxide, and hydrotalcite. When metal hydroxides are used, water is generated by the heat produced by ignition, allowing for rapid extinguishing of the fire.

[0033] Among the aforementioned flame retardants, phosphate esters such as red phosphorus and triphenyl phosphate (triphenyl phosphate), aluminum phosphite, ammonium polyphosphate, and zinc borate are preferred from the viewpoint of safety and cost. Of these, aluminum phosphite and ammonium polyphosphate are more preferred. The flame retardants listed above may be used individually or in combination of two or more, but it is preferable to use one individually, and more preferably to use aluminum phosphite. Because aluminum phosphite is expandable, fire-resistant materials containing it tend to have higher expansion pressure, making it easier to improve fire resistance more effectively.

[0034] The average particle size of the flame retardant is preferably 1 to 200 μm, more preferably 1 to 60 μm, even more preferably 3 to 40 μm, and even more preferably 5 to 20 μm. When the average particle size of the flame retardant is within the above range, the dispersibility of the flame retardant in the fire-resistant material is improved, making it possible to uniformly disperse the flame retardant in the binder resin or to increase the amount of flame retardant blended with the binder resin. Conversely, if the average particle size is outside the above range, it becomes difficult to disperse the flame retardant in the binder resin, making it difficult to uniformly disperse the flame retardant in the binder resin or to blend it in large quantities. The average particle size of the flame retardant is the median diameter (D50) value measured using a laser diffraction / scattering particle size distribution analyzer.

[0035] The flame retardant content of the fire-resistant material of the present invention is preferably 1 to 500 parts by mass, more preferably 3 to 100 parts by mass, and even more preferably 5 to 50 parts by mass, per 100 parts by mass of the binder resin. If the flame retardant content is above these lower limits, the fire resistance of the fire-resistant material improves. Conversely, if the flame retardant content is below these upper limits, it disperses more uniformly in the resin, resulting in superior moldability and other properties.

[0036] (Vulcanizing agent) The expansion layer in the refractory material of the present invention may contain a vulcanizing agent. In particular, when a rubber component is used as the binder resin, the inclusion of a vulcanizing agent increases the elasticity of the refractory material during expansion, improves the residual strength of the expanded refractory material, and makes it easier to suppress detachment from various components. Any known vulcanizing agent can be used without limitation, including, for example, sulfur compounds, organic peroxides, and azo compounds. The sulfur-based compound may be an inorganic compound such as sulfur, insoluble sulfur, precipitated sulfur, sulfur chloride, sulfur monochloride, or sulfur dichloride, but it may also be a sulfur-containing organic crosslinking agent. 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-ethylhexylcarbonate, etc. Examples of azo compounds include azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile). The vulcanizing agent may be used alone or in combination of two or more types.

[0037] Furthermore, among the vulcanizing agents mentioned above, those that are less likely to cause a crosslinking reaction at the temperature at which each component is kneaded during the manufacture of refractory materials, and that readily cause a crosslinking reaction of rubber components such as acrylonitrile-butadiene rubber due to the heat during a fire, are preferred. Specifically, sulfur-based compounds are preferred, and among these, inorganic compounds are preferred from the viewpoint of crosslinking properties, with sulfur being more preferred. If the refractory material contains a vulcanizing agent, the amount of vulcanizing 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 binder resin.

[0038] (Crosslinking promoter) The refractory material of the present invention may contain a vulcanization accelerator in addition to the vulcanizing agent. Examples of vulcanization accelerators include metal oxides such as zinc oxide and magnesium oxide, thiazole compounds, sulfenamide compounds, thiram compounds, dithiocarbamate compounds, guanidine compounds, and thiourea compounds. The vulcanization accelerator may be used alone or in combination of two or more types. When a vulcanization accelerator is used in the refractory material of the present invention, the amount of vulcanization accelerator to be blended 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 binder resin.

[0039] (Plasticizer) The fire-resistant material of the present invention preferably contains a plasticizer. By using a plasticizer, the above-mentioned maximum shear load can be easily adjusted to a desired range, and the ability to conform to various components during a fire tends to be improved. Examples of plasticizers are not particularly limited, but include phthalate-based plasticizers, adipic acid-based plasticizers, phosphate-based plasticizers, and alkyl sulfonic acid-based plasticizers.

[0040] Examples of phthalate-based plasticizers include di-2-ethylhexyl phthalate (DOP), di-n-octyl phthalate, diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), diundecyl phthalate (DUP), or phthalate esters of higher alcohols or mixed alcohols having approximately 10 to 13 carbon atoms. Examples of adipic acid-based plasticizers include dimethyl adipate, diethyl adipate, dipropyl adipate, dibutyl adipate, diisopropyl adipate, diisobutyl adipate, bis(2-ethylhexyl) adipate, dioctyl adipate, diisononyl adipate, diisodecyl adipate, bis(2-butoxyethyl) adipate, and adipic acid-based polyesters.

[0041] Examples of phosphate-based plasticizers include trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, octyldiphenyl phosphate, tributoxyethyl phosphate, trichloroethyl phosphate, tris(2-chloropropyl) phosphate, tris(2,3-dichloropropyl) phosphate, tris(2,3-dibromopropyl) phosphate, tris(bromochloropropyl) phosphate, bis(2,3-dibromopropyl)-2,3-dichloropropyl phosphate, bis(chloropropyl)monooctyl phosphate, tris(2-ethylhexyl) phosphate, triphenyl phosphate, tricresyl phosphate (TCP), trixylenyl phosphate, cresyldiphenyl phosphate, xylenyldiphenyl phosphate, and 2-ethylhexyldiphenyl phosphate. Examples of alkylsulfonic acid-based plasticizers include alkylsulfonic acid phenyl esters and N-butylbenzenesulfonamide.

[0042] Among the plasticizers mentioned above, adipic acid-based plasticizers or alkyl sulfonic acid-based plasticizers are preferred, and in particular, when a rubber component is used as the binder resin, alkyl sulfonic acid-based plasticizers are more preferred from the viewpoint of the fire-resistant material's ability to conform to the shape of various components during a fire. Furthermore, among alkyl sulfonic acid-based plasticizers, alkyl sulfonic acid phenyl esters are more preferred.

[0043] When using a plasticizer, the content of the plasticizer is not particularly limited, but is preferably 5 to 100 parts by mass, more preferably 10 to 60 parts by mass, and even more preferably 15 to 40 parts by mass, per 100 parts by mass of the binder resin. By adjusting the plasticizer content within the above range, the maximum shear load can be easily adjusted to the desired value, improving the shape conformability of the fire-resistant material to various components during a fire.

[0044] (Inorganic filler) The fire-resistant material of the present invention may further contain inorganic fillers other than flame retardants and thermally expandable graphite. The inorganic fillers other than flame retardants and thermally expandable graphite are not particularly limited and include, for example, metal carbonates such as alumina, basic magnesium carbonate, calcium carbonate, magnesium carbonate, zinc carbonate, strontium carbonate, and barium carbonate, silica, diatomaceous earth, dawsonite, barium sulfate, talc, clay, mica, montmorillonite, bentonite, activated clay, sepiolite, imogolite, sericite, glass fibers, glass beads, silica balloons, aluminum nitride, boron nitride, silicon nitride, carbon black, graphite, carbon fibers, carbon balloons, charcoal powder, various metal powders, potassium titanate, magnesium sulfate, lead zirconate titanate, aluminum borate, molybdenum sulfide, silicon carbide, stainless steel fibers, various magnetic powders, slag fibers, fly ash, and dewatered sludge. These inorganic fillers may be used individually or in combination of two or more types.

[0045] The average particle size of the inorganic filler is preferably 0.5 to 100 μm, and more preferably 1 to 50 μm. When the inorganic filler content is small, a smaller particle size is preferred from the viewpoint of improving dispersibility, and when the content is large, a larger particle size is preferred because as the filling level increases, the viscosity of the refractory material increases and the moldability decreases.

[0046] When the fire-resistant material of the present invention contains an inorganic filler other than a flame retardant and thermally expandable graphite, the amount of the inorganic filler is preferably 10 to 300 parts by mass, more preferably 10 to 200 parts by mass, per 100 parts by mass of the binder resin. When the amount of inorganic filler is within the above range, the mechanical properties of the fire-resistant material can be improved.

[0047] 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 this additive component is not particularly limited, and various additives can be used. Examples of such additives include lubricants, anti-shrinkage agents, crystal nucleating agents, colorants (pigments, dyes, etc.), ultraviolet absorbers, antioxidants, anti-aging agents, dispersants, gelation accelerators, fillers, reinforcing agents, flame retardant aids, antistatic agents, surfactants, and surface treatment agents, etc. The addition amount of the additive can be appropriately selected within a range that does not impair the moldability, etc. The additives may be used alone or in combination of two or more kinds.

[0048] Also, from the viewpoint of fire resistance, the residual strength after thermal expansion of the refractory material of the present invention is preferably 0.1 kgf / cm 2 or more, more preferably 0.3 kgf / cm 2 or more, still more preferably 0.5 kgf / cm 2 or more, and even more preferably 0.7 kgf / cm 2 or more. From the viewpoint of ensuring fire resistance by making the refractory material easy to expand, the above residual strength is preferably 2.0 kgf / cm 2 or less, and more preferably 1.5 kgf / cm 2 or less. The residual strength can be measured by the method described in the examples.

[0049] (Thickness) The expansion layer of the refractory material of the present invention preferably has a sheet-like shape, and its thickness is not particularly limited, but from the viewpoints of fire resistance and handleability, 0.2 to 10 mm is preferable, and 0.5 to 3.0 mm is more preferable.

[0050] (Manufacturing method of expansion layer) The expansion layer of the refractory material in the present invention can be manufactured, for example, as follows. First, a predetermined amount of thermally expandable graphite, binder resin, plasticizer, flame retardant, vulcanizing agent, inorganic filler, and other components that are blended as necessary are kneaded with a kneader such as a kneading roll to obtain a refractory resin composition. Next, the obtained refractory resin composition can be formed into a sheet shape or the like by a known forming method such as press molding, calender molding, extrusion molding, etc. to obtain an expansion layer. The temperature during mixing 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 vulcanizing agent is included, the temperature should be such that the vulcanizing agent is less likely to crosslink. Therefore, the mixing temperature is preferably 40 to 100°C, and more preferably 50 to 80°C. The temperature at which the material is formed into a sheet is preferably 70 to 110°C, and more preferably 80 to 100°C.

[0051] (Layers other than the expansion layer) The fire-resistant material of the present invention may consist only of an expansion layer, but may also have layers other than the expansion layer, such as a surface layer or an adhesive layer, as described below.

[0052] (Surface material) The fire-resistant material of the present invention may have a surface layer material provided on one or both surfaces of the expansion layer, from the viewpoint of improving appearance and scratch resistance. The surface layer material is a resin layer containing a binder resin. In addition to the binder resin, the surface layer material may contain the above-mentioned flame retardants, plasticizers, inorganic fillers, etc., but may also consist only of the binder resin. The binder resin of the surface layer is not particularly limited, but from the viewpoint of suppressing corrosion of various components using fire-resistant materials, it is preferable that it does not contain halogens in its molecular structure.

[0053] The type of binder resin used in the surface layer is not particularly limited, but examples include polyester resins such as polyethylene terephthalate, polyolefin resins such as polyethylene and polypropylene, α-olefin-alkyl (meth)acrylate copolymer resins such as ethylene-methyl methacrylate copolymer resin, rubber resins such as acrylonitrile rubber-butadiene rubber, styrene-butadiene rubber, butadiene rubber, and chloroprene rubber, and polyvinyl chloride resin. The surface layer is preferably a layer that does not contain thermally expandable graphite. Therefore, in a fire-resistant material equipped with a surface layer, the expansion layer expands in the planar and thickness directions during a fire, while the surface layer does not expand. Generally, the surface layer is covered by the expanded expansion layer. The thickness of the surface material is, for example, 5 to 1000 μm, preferably 5 to 500 μm.

[0054] (Adhesive layer) The fire-resistant material of the present invention may have an adhesive layer on one or both surfaces of the expansion layer, from the viewpoint of facilitating attachment to various components. The adhesive layer is not particularly limited and may use any commonly used adhesive, but for example, an acrylic adhesive can be used. The thickness of the adhesive layer is, for example, 10 to 500 μm, preferably 50 to 300 μm. Furthermore, the fire-resistant material may have both an adhesive layer and a surface layer. In this case, it is preferable to have a fire-resistant material with an adhesive layer on one side of the expansion layer and a surface layer on the other side.

[0055] (Application) The fire-resistant material of the present invention can be used in various types of fixtures in detached houses, apartment buildings, high-rise buildings, commercial facilities, public facilities, etc., as well as in various vehicles such as automobiles and trains, ships, and aircraft, but it is preferable to use it in fixtures. Specifically, it can be used in walls, beams, columns, floors, bricks, roofs, boards, sashes, shoji screens, doors, fire doors, sliding doors, transoms, wiring, piping, etc., but it is preferable to use it in fire doors or sashes. The fire-resistant material of the present invention has good expansion properties that can seal gaps and easily follows the deformation of materials during a fire, so it is particularly preferable to apply it to the gaps of fire doors or sashes and use it as a fire-resistant material. [Examples]

[0056] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0057] [Evaluation Method] (1) Expansion ratio The refractory material for each example and comparative example was made to a predetermined size (50 mm wide, 50 mm long). The refractory material of the predetermined size was placed on the bottom surface of a stainless steel plate (98 mm square, 0.3 mm thick), and the refractory material was placed in an electric furnace preheated to 400°C and heated for 20 minutes. The expansion ratio was determined by dividing the thickness of the refractory material after heating by the thickness of the refractory material before heating.

[0058] (2)Residue strength Using the expanded layer of the refractory material, which has been expanded according to the expansion ratio test described above, as a test specimen, a compression test was performed using a compression tester (Kato Tech Finger Filling Tester) to 0.25 cm. 2 The material was compressed at a speed of 0.1 cm / second using an indenter, and the fracture stress was measured. This was then used to determine the residue strength (kgf / cm²). 2 )

[0059] (3) Maximum shear load This will be explained using Figures 1 and 2. Fire-resistant material was cut to dimensions (width x length) 25 mm x 25 mm, and fire-resistant material 13 was prepared as a sample for measuring the maximum shear load. Next, two SUS plates 11 and 12 were prepared. The dimensions of each SUS plate were 0.3 mm thick, 50 mm wide, and 100 mm long. Two SUS plates 11 and 12 were placed facing each other using spacers (not shown) at a distance of three times the thickness t of the fire-resistant material 13. The opposing surface area of ​​the SUS plates was also arranged to be 50 mm x 50 mm. Next, the fire-resistant material 13, cut to 25 mm x 25 mm as described above, was attached to the surface of one of the SUS plates 11. The attachment was done using a 200 μm thick acrylic adhesive (tesa 4965). In the case of fire-resistant material with a surface layer, the side opposite the surface layer was attached to the surface of the SUS plate 11 using the acrylic adhesive. In this way, a structure 14 was fabricated having two SUS plates 11 and 12, and a fire-resistant material 13 attached to the surface of one of the SUS plates. As described above, the structure 14 was heated in an electric furnace at 400°C for 20 minutes. This caused the refractory material 13 to expand, as shown in Figure 2, and closed the space between the SUS plates 11 and 12, thus creating a shear load measurement sample 15. Tensile tests were performed on the SUS plates 11 and 12 of the shear load measurement sample 15 prepared in this manner by pulling them in the shear direction. Specifically, SUS plate 11 was fixed, and SUS plate 12 was pulled at a speed of 1 mm / min. An Orientec Tensilon RTC1210A tensile testing machine was used, and the measurement temperature was set to 25°C. The tensile condition in the tensile test was 1 mm / min. The maximum value of the shear load measured during the tensile test was defined as the maximum shear load (N).

[0060] (4) Corrosive After the (3) maximum shear load test described above, the expanded fire-resistant material was removed, and the surface of the SUS plate was visually inspected and evaluated according to the following criteria. <Rating> ○: No corrosion was detected. ×: Corrosion was confirmed.

[0061] (5) tanδ at 200℃ The tanδ (loss tangent) value of refractory material was measured at 200°C using a dynamic viscoelasticity analyzer (Rheometrics "ARES"). The measurement was performed using the shear method under conditions of 1% strain, 1 Hz frequency, and 5°C / min heating rate.

[0062] The various components used in each example and comparative example are as follows. (Binder resin) • NBR (high viscosity) acrylonitrile-butadiene rubber, manufactured by Nippon Zeon Co., Ltd., "Nipol DN401", Mooney viscosity ML(1+4) 100℃: 77.5, nitrile content 18% by mass • NBR (medium viscosity) acrylonitrile-butadiene rubber, manufactured by Nippon Zeon Co., Ltd. "Nipol DN401L", Mooney viscosity ML(1+4) 100℃: 65, nitrile content 18% by mass • NBR (low viscosity) acrylonitrile-butadiene rubber, manufactured by Nippon Zeon Co., Ltd. "Nipol DN101LL", Mooney viscosity ML(1+4) 100℃: 32, nitrile content 18% by mass • NBR (Non-Trimester NT) Acrylonitrile-butadiene rubber, manufactured by Nippon Zeon Co., Ltd. "NipolDN302", Mooney viscosity ML(1+4) 100℃: 62.5, Nitrile content 27.5% by mass • CR chloroprene rubber, Denka Co., Ltd. "M-40", Mooney viscosity ML (1+4) 100℃: 46 • BR Butadiene rubber, manufactured by Nippon Zeon Co., Ltd. "NipolBR1220", Mooney viscosity ML (1+4) 100℃: 44 SBR (Styrene-Butadiene Rubber), manufactured by Zeon Corporation, "Nipol 1723", Mooney viscosity ML (1+4) 100℃: 47 • PVC (polyvinyl chloride), manufactured by Kaneka Corporation, "S1001"

[0063] (Flame retardant) • Aluminum phosphite, manufactured by Taihei Chemical Industry Co., Ltd., "APA100"

[0064] (Plasticizer) • Alkyl sulfonic acid-based alkyl sulfonate phenyl ester, manufactured by LANXESS, "Mesamoll" • Adipic acid-based bis[2-(2-butoxyethoxy)ethyl]adipate, manufactured by Daihachi Chemical Industry Co., Ltd. "BXA-N"

[0065] (Vulcanizing agent) • Sulfur-based, "Colloidal Sulfur" manufactured by Hosoi Chemical Industry Co., Ltd. • Peroxide-based, manufactured by Nippon Oil & Fats Co., Ltd., "Parkmill D"

[0066] (Thermally expandable graphite) • Thermally expandable graphite 1: ADT351, manufactured by ADT Corporation, expansion start temperature 170°C • Thermally expandable graphite 2: "EXP42S160" manufactured by Fuji Graphite Industry Co., Ltd., expansion start temperature 160℃ • Thermally expandable graphite 3: "EXP50HO" manufactured by Fuji Graphite Co., Ltd., expansion start temperature 220℃

[0067] (Surface material) The surface material used consisted of the following binder resins. • PET (Polyethylene Terephthalate), 50 μm thick • Ethylene-methyl methacrylate copolymer resin, 300 μm thick • NBR (Acrylonitrile-butadiene rubber), 100 μm thick PVC (polyvinyl chloride), 100 μm thick

[0068] (Examples 1-14, Comparative Examples 1-2) Using the formulations shown in Tables 1 and 2, each component for forming the expansion layer was kneaded in a plastmill at 60°C for 5 minutes to obtain a refractory resin composition. The obtained refractory resin composition was press-molded at 90°C for 3 minutes to obtain a refractory material consisting of a 1.5 mm thick sheet-like expansion layer. The evaluation results are shown in Tables 1 and 2.

[0069] (Examples 15-19) Except for changing the formulation shown in Table 2, a sheet-like expansion layer with a thickness of 1.5 mm was obtained in the same manner as in Example 1. Then, the surface material shown in Table 2 was laminated to one side of the expansion layer to obtain a fire-resistant material. The lamination of the surface material was performed by hot pressing (90°C). The evaluation results are shown in Table 2.

[0070] [Table 1]

[0071] [Table 2]

[0072] The fire-resistant materials in each embodiment had an expansion ratio of 3 times or more, exhibiting good expansion characteristics, and a maximum shear load of 20N or more. As a result, they showed good ability to follow the deformation of various components such as fire doors and sashes during a fire, and were found to have excellent fire resistance. In contrast, the fire-resistant materials in Comparative Examples 1 and 2 had a maximum shear load of less than 20N, resulting in poor ability to follow the deformation of various components during a fire and inferior fire resistance. [Explanation of Symbols]

[0073] 11 SUS board 12 SUS board 13 Fireproof materials 14 Structure 15. Shear load measurement sample

Claims

1. A heat-expandable fire-resistant material comprising an expansion layer containing a binder resin and heat-expandable graphite, When the aforementioned heat-expandable fire-resistant material is cut to dimensions of 50 mm x 50 mm and heated at 400°C for 20 minutes, the expansion ratio in the thickness direction is 3 times or more. A heat-expandable fire-resistant material is prepared by cutting the heat-expandable fire-resistant material to dimensions of 25 mm x 25 mm, attaching it to the surface of one of two SUS plates which are placed facing each other at a distance of three times the thickness of the expansion layer of the heat-expandable fire-resistant material, and with a facing area of ​​50 mm x 50 mm between the SUS plates, and then heating the sample obtained by heating at 400°C for 20 minutes. The maximum shear load measured on the sample under tensile conditions of 1 mm / min is 20 N or more.

2. The heat-expandable fire-resistant material according to claim 1, wherein the binder resin contains a rubber component.

3. The heat-expandable fire-resistant material according to claim 1 or 2, wherein the binder resin does not contain halogens in its molecular structure.

4. The heat-expandable fire-resistant material according to claim 1 or 2, wherein the binder resin contains a nitrile group.

5. A heat-expandable fire-resistant material according to claim 1 or 2, comprising a surface material that does not contain heat-expandable graphite.

6. The heat-expandable fire-resistant material according to claim 5, wherein the binder resin contained in the surface material does not contain halogens in its molecular structure.

7. A heat-expandable fire-resistant material according to claim 1 or 2, used as a fire-resistant component for fire doors and sashes.

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