Refractory material and method for manufacturing the same

Abstract

To provide a refractory material that has improved moldability and mechanical strength, and also improved fire resistance.SOLUTION: A refractory material contains at least one polymer compound selected from a group consisting of a resin and rubber, thermally expandable graphite, and an anionic surfactant.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a refractory material containing thermally expandable graphite and a method for producing the refractory material. [Background technology]

[0002] In the field of construction, fire-resistant materials are used in building materials such as fittings, pillars, and wall materials for fire prevention. Examples of fire-resistant materials include those made by compounding thermally expandable graphite with resin in addition to flame retardants and inorganic fillers (see, for example, Patent Document 1). Such fire-resistant materials expand when heated, and the combustion residue forms a fire-resistant insulating layer, thereby demonstrating fire-resistant insulating performance. When manufacturing fire-resistant materials containing thermally expandable graphite, extrusion molding or calendar molding is often used. However, these molding methods place a large load on the thermally expandable graphite, and the thermally expandable graphite is often crushed during molding, resulting in a decrease in fire resistance. On the other hand, a method for producing a fire-resistant material by a coating method using latex, without using the above-mentioned molding method, is known. For example, Patent Document 2 describes an invention relating to a fire-resistant material containing expandable graphite, chloroprene latex, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-141463 [Patent Document 2] Special Publication No. 03-503654 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional methods for producing a fire-resistant material using latex, the surface smoothness of the resulting sheet-shaped fire-resistant material may be poor, and there is room for improvement in terms of formability. Furthermore, the conventional methods have the problem that the resulting fire-resistant material does not have sufficient mechanical strength (such as tensile elongation) and is therefore not durable for practical use. Therefore, an object of the present invention is to provide a fire-resistant material that has good formability and mechanical strength, and also has excellent fire resistance. [Means for solving the problem]

[0005] As a result of intensive research to solve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by a fire-resistant material containing at least one polymer compound selected from the group consisting of resins and rubbers, thermally expandable graphite, and an anionic surfactant. That is, the present invention relates to the following [1] to

[12] . [1] A fire-resistant material containing at least one polymer compound selected from the group consisting of resins and rubbers, thermally expandable graphite, and an anionic surfactant. [2] The fire-resistant material according to [1] above, wherein the molecular weight of the polymer compound is 50,000 to 2,000,000. [3] The fire-resistant material according to [1] or [2] above, wherein the anionic surfactant contains a sulfonate surfactant. [4] The fire-resistant material according to [3] above, wherein the sulfonate surfactant is a naphthalenesulfonic acid compound. [5] The fire-resistant material according to any one of the above [1] to [4], wherein the content of the anionic surfactant is 0.01 to 3 mass % based on the total amount of the fire-resistant material. [6] The fire-resistant material according to any one of the above [1] to [5], wherein the content of the thermally expandable graphite is 20 to 500 parts by mass per 100 parts by mass of the polymer compound. [7] The fire-resistant material according to any one of the above [1] to [6], wherein the polymer compound is at least one selected from the group consisting of ethylene-vinyl acetate copolymer, polyvinyl acetate resin, acrylic resin, styrene-butadiene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, butadiene rubber, and natural rubber. [8] The fire-resistant material according to any one of the above [1] to [7], wherein the polymer compound is an acrylonitrile-butadiene rubber having an acrylonitrile content of 10 to 35 mass %. [9] A method for producing a fire-resistant material, comprising the step (1) of producing a coating material containing a polymer emulsion containing an anionic surfactant and thermally expandable graphite.

[10] The method for producing a fire-resistant material according to the above [9], wherein the content of the anionic surfactant is 0.01 to 3 mass % based on the total amount of the fire-resistant material.

[11] A method for producing a fire-resistant material according to the above [9] or

[10] , comprising the steps of: (1) producing a paint; (2) applying the paint; and (3) drying the applied paint at a temperature of 140°C or less.

[12] A method for producing a fire-resistant material according to the above item [9] or

[10] , comprising the steps of: (1) producing a coating material; (2') fluidizing and drying the coating material to form a powder; and (3') pressing the powder. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a fire-resistant material that has good formability and mechanical strength, and is also excellent in fire resistance. DETAILED DESCRIPTION OF THE INVENTION

[0007] [Fireproof material] The fire-resistant material of the present invention contains at least one polymer compound selected from the group consisting of resins and rubbers, thermally expandable graphite, and an anionic surfactant.

[0008] <Anionic surfactants> The fireproof material of the present invention contains an anionic surfactant. If the fireproof material does not contain an anionic surfactant, the surface smoothness of the fireproof material will be reduced, and the moldability will be poor when producing a sheet-shaped fireproof material. Furthermore, if the fireproof material does not contain an anionic surfactant, the mechanical strength and fire resistance of the fireproof material will be likely to decrease. This is presumably because, if the anionic surfactant is not contained, the thermally expandable graphite will be easily crushed when producing the fireproof material. The method for producing the fireproof material will be described later.

[0009] Anionic surfactants are surfactants having, as a hydrophilic group, a carboxylate, a sulfate, a sulfonate, a phosphate, etc. Specific examples of anionic surfactants include carboxylate surfactants, sulfate surfactants, sulfonate surfactants, and phosphate surfactants.

[0010] The carboxylate surfactant is not particularly limited as long as it is a surfactant having a carboxylate as a hydrophilic group, and examples thereof include fatty acid salts having 6 to 30 carbon atoms, polycarboxylic acid salts, polyoxyalkylene alkyl ether carboxylates, polyoxyalkylene alkylamide ether carboxylates, rosin acid salts, dimer acid salts, polymer acid salts, and tall oil fatty acid salts.

[0011] The sulfate salt surfactant is not particularly limited as long as it is a surfactant having a sulfate salt as a hydrophilic group, and examples thereof include alkyl sulfate salts, polyoxyalkylene alkyl sulfate salts, and polyoxyalkylene alkyl phenyl ether sulfate salts.

[0012] The sulfonate surfactant is not particularly limited as long as it is a surfactant having a sulfonate as a hydrophilic group, and examples thereof include naphthalenesulfonate compounds such as alkylnaphthalenesulfonates, naphthalenesulfonates, condensate salts of alkylnaphthalenesulfonic acids, and condensate salts of naphthalenesulfonic acids, alkylbenzenesulfonates, alkylsulfonates, and diphenyl ether sulfonates. The condensate salts of alkylnaphthalenesulfonic acid include, for example, formalin condensate salts of alkylnaphthalenesulfonic acid, and the condensate salts of naphthalenesulfonic acid include, for example, formalin condensate salts of naphthalenesulfonic acid. Examples of the alkyl sulfonates include fatty acid sulfonates having 6 to 30 carbon atoms, and fatty acid ester sulfonates having 6 to 30 carbon atoms. Examples of the fatty acids having 6 to 10 carbon atoms include lauric acid, myristic acid, palmitic acid, and oleic acid.

[0013] The phosphate salt surfactant is not particularly limited as long as it is a surfactant having a phosphate salt as a hydrophilic group, and examples thereof include alkyl phosphate salts, alkylphenyl phosphate salts, and polyoxyalkylene alkyl phosphate salts. Examples of salts of hydrophilic groups include metal salts (salts of Na, K, Ca, Mg, Zn, etc.), ammonium salts, alkanolamine salts, and aliphatic amine salts.

[0014] Among the above-mentioned anionic surfactants, from the viewpoint of improving the moldability, mechanical strength, and fire resistance of the fire-resistant material, it is preferable that the anionic surfactant contains a sulfonate surfactant, and it is more preferable that the anionic surfactant consists solely of a sulfonate surfactant. Among the sulfonate surfactants, naphthalenesulfonic acid compounds are particularly preferable.

[0015] The content of the anionic surfactant based on the total amount of the fire-resistant material is not particularly limited, but from the viewpoint of improving the formability, mechanical strength, and fire resistance of the fire-resistant material, it is preferably 0.01 to 3 mass%, more preferably 0.05 to 2 mass%, and even more preferably 0.1 to 1 mass%.

[0016] <Polymer compounds> The fire-resistant material of the present invention contains at least one polymer compound selected from the group consisting of resins and rubbers. The polymer compound forms a matrix in the fire-resistant material. That is, the fire-resistant material has thermally expandable graphite and anionic surfactant dispersed in a matrix made of the polymer compound. Examples of polymer compounds contained in the fire-resistant material include resins such as polyolefin resins such as polypropylene resin, polyethylene resin, and ethylene-vinyl acetate copolymer, polyvinyl acetate resin, polyvinyl chloride resin, and acrylic resin, and rubbers such as styrene-butadiene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, butadiene rubber, natural rubber, isoprene rubber, and butyl rubber. The polymer compounds may be used alone or in combination of two or more.

[0017] Among these, from the viewpoint of improving the moldability, mechanical strength, and fire resistance of the fire-resistant material, the polymer compound is preferably at least one selected from the group consisting of ethylene-vinyl acetate copolymer, polyvinyl acetate resin, acrylic resin, styrene-butadiene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, butadiene rubber, and natural rubber. Among these, the polymer compound is more preferably at least one selected from the group consisting of ethylene-vinyl acetate copolymer, polyvinyl acetate resin, styrene-butadiene rubber, acrylonitrile-butadiene rubber, and chloroprene rubber, with acrylonitrile-butadiene rubber being even more preferred.

[0018] The amounts of the comonomers of acrylonitrile butadiene rubber, styrene butadiene rubber, and ethylene-vinyl acetate copolymer are preferably adjusted as follows from the viewpoint of improving the moldability, mechanical strength, and fire resistance of the fire-resistant material. The acrylonitrile content of the acrylonitrile butadiene rubber is not particularly limited, but is preferably 10 to 35 mass %, more preferably 15 to 35 mass %, and even more preferably 25 to 30 mass %. The styrene content of the styrene-butadiene rubber is not particularly limited, but is preferably 10 to 35% by mass, and more preferably 20 to 30% by mass. The vinyl acetate content of the ethylene-vinyl acetate copolymer is not particularly limited, but is preferably 10 to 35% by mass, and more preferably 20 to 30% by mass.

[0019] From the viewpoint of improving fire resistance, the molecular weight of the polymer compound is preferably 50,000 to 2,000,000, more preferably 100,000 to 1,500,000, and even more preferably 150,000 to 1,000,000. In this specification, molecular weight means weight-average molecular weight. The weight-average molecular weight is a value measured by gel permeation chromatography in terms of standard polystyrene.

[0020] The method for producing the polymer compound of the present invention is not particularly limited, and the polymer compound may be produced by a known method, but it is particularly preferred that the polymer compound be produced by emulsion polymerization. When a polymer compound obtained by emulsion polymerization is used, a fire-resistant material excellent in moldability, mechanical strength, and fire resistance can be easily obtained.

[0021] <Thermal Expandable Graphite> The fireproof 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 treating raw material powder such as natural flaky graphite, pyrolytic graphite, or kish graphite with a strong oxidizing agent to produce a graphite intercalation compound. Examples of strong oxidizing agents include inorganic acids such as concentrated sulfuric acid, nitric acid, and selenic acid, 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 or the like as described above may be further neutralized with ammonia, an aliphatic lower amine, an alkali metal compound, an alkaline earth metal compound, or the like.

[0022] The content of thermally expandable graphite in the fire-resistant material of the present invention is preferably 20 to 500 parts by mass, more preferably 50 to 300 parts by mass, and even more preferably 100 to 250 parts by mass, relative to 100 parts by mass of the polymer compound. When the content of thermally expandable graphite is equal to or greater than these lower limits, the expansion pressure of the fire-resistant material is easily increased, improving fire resistance. When the content of thermally expandable graphite is equal to or less than these upper limits, moldability and the like are improved.

[0023] The thermally expandable graphite in the present invention preferably has an average aspect ratio of at least 15, more preferably at least 20, and usually at most 1000. When the average aspect ratio of the thermally expandable graphite is at least these lower limit values, the expansion pressure of the refractory material tends to be increased. The aspect ratio of thermally expandable graphite is determined by measuring the maximum dimension (long diameter) and minimum dimension (short diameter) of 10 or more (e.g., 50) pieces of thermally expandable graphite, and calculating the average value of these ratios (maximum dimension / minimum dimension).

[0024] The average particle size of the thermally expandable graphite is not particularly limited, but is preferably 50 to 500 μm, and more preferably 100 to 400 μm. The average particle size of the thermally expandable graphite is determined as the average of the maximum dimensions of 10 or more (for example, 50) pieces of thermally expandable graphite. The minimum and maximum dimensions of the thermally expandable graphite can be measured using, for example, a field emission scanning electron microscope (FE-SEM).

[0025] <Plasticizer> The fireproof material of the present invention may contain a plasticizer. Use of a plasticizer tends to improve moldability. When a plasticizer is used, the content of the plasticizer is not particularly limited, but is preferably 10 to 200 parts by mass, more preferably 20 to 60 parts by mass, per 100 parts by mass of the polymer compound. When the content of the plasticizer is equal to or greater than these lower limits, the moldability of the fireproof material is improved. When the content of the plasticizer is equal to or less than these upper limits, the fireproofness tends to be improved.

[0026] Specific examples of the plasticizer include phthalate ester plasticizers such as 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 about 10 to 13 carbon atoms, di-2-ethylhexyl adipate (DOA), diisobutyl adipate (DIBA), dibutyl adipate (DBA), di-n-octyl adipate, di-n-decyl adipate, and diisodecyl adipate. Examples of suitable plasticizers include aliphatic ester-based plasticizers such as dibutyl sebacate, di-2-ethylhexyl azelate, dibutyl sebacate, di-2-ethylhexyl sebacate, and dibutoxyethoxyethyl adipate, trimellitic acid ester-based plasticizers such as tri-2-ethylhexyl trimellitate (TOTM), tri-n-octyl trimellitate, tridecyl trimellitate, triisodecyl trimellitate, and di-n-octyl-n-decyl trimellitate, process oils such as mineral oil, and polyhydric alcohol-based plasticizers such as polyethylene glycol and polypropylene glycol. Among these, polyhydric alcohol-based plasticizers are preferred.

[0027] <Flame retardant> The fire-resistant material of the present invention preferably contains a flame retardant, which 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 phosphates such as sodium phosphate, potassium phosphate, and magnesium phosphate, metal phosphites such as sodium phosphite, potassium phosphite, magnesium phosphite, and aluminum phosphite, ammonium polyphosphate, red phosphorus, etc. Examples of flame retardants also include compounds represented by the following general formula (1):

[0028] [ka]

[0029] In the general formula (1), R 1 and R 3 are the same or different and represent a hydrogen atom, a linear or branched alkyl group having 1 to 16 carbon atoms, or an aryl group having 6 to 16 carbon atoms. 2 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.

[0030] Specific examples of the compound 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-dimethyl-butylphosphonic 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, etc. The flame retardants may be used alone or in combination of two or more.

[0031] As the flame retardant of the present invention, boron compounds and metal hydroxides can also be used. Examples of boron compounds include zinc borate. Examples of metal hydroxides include aluminum hydroxide, magnesium hydroxide, calcium hydroxide, hydrotalcite, etc. When a metal hydroxide is used, water is produced by the heat generated by ignition, and the fire can be quickly extinguished.

[0032] Among the flame retardants, from the viewpoints of safety, cost, etc., red phosphorus, phosphate esters such as triphenyl phosphate (triphenyl phosphate), aluminum phosphite, ammonium polyphosphate, and zinc borate are preferred. Among these, aluminum phosphite and ammonium polyphosphate are more preferred, and aluminum phosphite is even more preferred. Because aluminum phosphite has expansive properties, fire-resistant materials containing it are likely to have increased expansion pressure, making it easier to more effectively improve fire resistance.

[0033] 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 polymer compound and increase the amount of flame retardant blended relative to the polymer compound. On the other hand, when the average particle size is outside the above range, it becomes difficult to disperse the flame retardant in the polymer compound, making it difficult to uniformly disperse the flame retardant in the polymer compound or to blend a large amount of the flame retardant in the polymer compound. The average particle size of the flame retardant is the median diameter (D50) measured by a laser diffraction / scattering particle size distribution analyzer.

[0034] The content of the flame retardant in the fire-resistant material of the present invention is preferably 5 to 1,000 parts by mass, more preferably 10 to 300 parts by mass, and even more preferably 20 to 100 parts by mass, per 100 parts by mass of the polymer compound. When the content of the flame retardant is equal to or greater than these lower limits, the fire resistance of the fire-resistant material is improved. On the other hand, when the content of the flame retardant is equal to or less than these upper limits, the flame retardant is more easily dispersed uniformly in the polymer compound.

[0035] <Inorganic fillers> The fire-resistant material of the present invention may further contain an inorganic filler other than the flame retardant and the thermally expandable graphite. The inorganic filler other than the flame retardant and the thermally expandable graphite is not particularly limited, and examples thereof include metal oxides such as alumina, zinc oxide, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, and ferrite; metal carbonates such as 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 fiber, glass beads, silica-based balloons, aluminum nitride, boron nitride, silicon nitride, carbon black, graphite, carbon fiber, carbon balloons, charcoal powder, various metal powders, potassium titanate, magnesium sulfate, lead zirconate titanate, zinc stearate, calcium stearate, aluminum borate, molybdenum sulfide, silicon carbide, stainless steel fiber, various magnetic powders, slag fiber, fly ash, and dewatered sludge. These inorganic fillers may be used alone or in combination of two or more.

[0036] The average particle size of the inorganic filler is preferably 0.5 to 100 μm, more preferably 1 to 50 μm. When the content of the inorganic filler is low, a small particle size is preferred from the viewpoint of improving dispersibility, but when the content is high, a large particle size is preferred because the viscosity of the refractory material increases and moldability decreases as the content increases.

[0037] When the fire-resistant material of the present invention contains an inorganic filler other than a flame retardant and thermally expandable graphite, the content thereof is preferably 10 to 300 parts by mass, more preferably 10 to 200 parts by mass, per 100 parts by mass of the polymer compound. When the content of the inorganic filler is within the above range, the mechanical properties of the fire-resistant material can be improved.

[0038] The fireproof material of the present invention may contain various additive components as required, provided that the object 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 crosslinking agents, lubricants, anti-shrinkage agents, crystal nucleating agents, colorants (pigments, dyes, etc.), ultraviolet absorbers, antioxidants, antiaging agents, dispersants, gelation accelerators, fillers, reinforcing agents, flame retardant aids, antistatic agents, surfactants, vulcanizing agents, and surface treatment agents. The amount of additive added can be appropriately selected within a range that does not impair moldability, etc. The additives may be used alone or in combination of two or more.

[0039] The fireproof material is preferably in the form of a sheet, and although there are no particular limitations on the thickness thereof, from the viewpoints of fire resistance and ease of handling, the thickness is preferably 0.2 to 10 mm, more preferably 0.5 to 3.0 mm.

[0040] <Fireproofing material manufacturing method> The method for producing the fire-resistant material of the present invention is not particularly limited, but preferably includes step (1) of producing a coating material containing a polymer emulsion containing an anionic surfactant and thermally expandable graphite. The method including step (1) makes it possible to obtain a fire-resistant material containing at least one polymer compound selected from the group consisting of the above-mentioned resins and rubbers, thermally expandable graphite, and an anionic surfactant.

[0041] The polymer emulsion of the present invention is a liquid containing a dispersion medium (liquid), a polymer compound as a dispersoid dispersed in the dispersion medium, and an anionic surfactant. The dispersion medium is preferably water. That is, the polymer emulsion of the present invention preferably contains a polymer compound, an anionic surfactant, and water.

[0042] As the polymer compound, the above-mentioned compounds can be used without any particular limitation, and the same applies to preferred polymer compounds. That is, the polymer compound is preferably at least one selected from the group consisting of ethylene-vinyl acetate copolymer, polyvinyl acetate resin, acrylic resin, styrene-butadiene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, butadiene rubber, and natural rubber. Among these, the polymer compound is more preferably at least one selected from the group consisting of ethylene-vinyl acetate copolymer, polyvinyl acetate resin, styrene-butadiene rubber, acrylonitrile-butadiene rubber, and chloroprene rubber, and acrylonitrile-butadiene rubber is even more preferred. The content of the polymer compound in the polymer emulsion is preferably 30 to 70% by mass, more preferably 40 to 60% by mass, based on the total amount of the polymer emulsion.

[0043] The anionic surfactant may be any of those listed above without any particular limitation, and the same applies to preferred compounds. The anionic surfactant preferably includes a sulfonate surfactant, and among the sulfonate surfactants, a naphthalenesulfonic acid compound is particularly preferred. The content of the anionic surfactant in the polymer emulsion is preferably 0.05 to 4 mass %, more preferably 0.2 to 2 mass %, based on the total amount of the polymer emulsion. In addition, in the fireproof material produced by the method including step (1), the content of the anionic surfactant based on the total amount of the fireproof material is not particularly limited, but from the viewpoint of improving the formability, mechanical strength, and fire resistance of the fireproof material, it is preferably 0.01 to 3 mass%, more preferably 0.05 to 2 mass%, and even more preferably 0.1 to 1 mass%.

[0044] The polymer emulsion of the present invention is preferably obtained by emulsion polymerization of monomers for producing a polymer compound. The monomers for producing the polymer compound are, for example, ethylene and vinyl acetate if the polymer compound is an ethylene-vinyl acetate copolymer, and vinyl acetate if the polymer compound is a polyvinyl acetate resin. Furthermore, if the polymer compound is a styrene-butadiene rubber, the monomers are styrene and butadiene; if the polymer compound is an acrylonitrile-butadiene rubber, the monomers are acrylonitrile and butadiene; and if the polymer compound is a chloroprene rubber, the monomers are chloroprene.

[0045] Specifically, the polymer emulsion can be produced by adding an anionic surfactant as an emulsifier and monomers to a dispersion medium containing water as the main component (for example, a dispersion medium containing 90 mass % or more of water, preferably a dispersion medium consisting of water), and emulsion-polymerizing the monomers while stirring. In emulsion polymerization, additives such as a polymerization initiator, a chain transfer agent, and a stabilizer may be added as necessary. When a polymer compound is produced by emulsion polymerization in this way, it is possible to produce a polymer compound with a relatively high molecular weight. Furthermore, a fire-resistant material containing a polymer compound obtained by emulsion polymerization tends to have good fire resistance.

[0046] The polymer emulsion obtained by emulsion polymerization can be used as it is in the step (1) described above. However, instead of using the polymer emulsion obtained by emulsion polymerization as it is, it may be used as the polymer emulsion in the step (1) after, for example, partially evaporating the dispersion medium or adding a separate solvent. The amount of the monomer in the emulsion polymerization is preferably adjusted and blended so that the amount of the polymer compound formed in the emulsion falls within the above-mentioned range, and the amount of the anionic surfactant in the emulsion polymerization is preferably adjusted and blended so that the amount of the anionic surfactant in the emulsion falls within the above-mentioned range.

[0047] In step (1), a polymer emulsion and thermally expandable graphite are mixed and dispersed to produce a paint. The paint is in the form of a slurry in which the thermally expandable graphite is dispersed in the polymer emulsion. The paint production method in step (1) involves mixing and dispersing in a solution, which prevents the thermally expandable graphite from being crushed. As a result, the resulting fire-resistant material has excellent moldability, mechanical strength, and fire resistance. This effect is best exhibited when an anionic surfactant containing a sulfonate-type surfactant is used, and this effect is particularly well exhibited when a naphthalenesulfonic acid-based compound is used among sulfonate-type surfactants. The content of the anionic surfactant relative to the total amount of the paint is preferably 0.01 to 3 mass %, more preferably 0.1 to 1 mass %. When the content of the anionic surfactant is within this range, crushing of the thermally expandable graphite is easily suppressed. The content of the polymer compound relative to the total amount of the paint is preferably 5 to 25 mass%, more preferably 8 to 15 mass%, and the content of the thermally expandable graphite relative to the total amount of the paint is preferably 12 to 25 mass%, more preferably 15 to 21 mass%.

[0048] Furthermore, in addition to the polymer emulsion and thermally expandable graphite, a flame retardant, an inorganic filler, a plasticizer, various additives, etc. may be blended and mixed as needed to produce a coating material. The mixing can be carried out by a known method, and for example, it is preferable to mix by stirring using a mixing device such as a stirrer. The contents of the flame retardant, inorganic filler, and plasticizer in the paint may be appropriately adjusted so that the content of each component in the fire-resistant material falls within the ranges described above. The content of each component in the paint on a solid basis is the same as the content of each component described for the fire-resistant material.

[0049] The fire-resistant material of the present invention is preferably produced by a method comprising the steps of producing a paint by the above-mentioned step (1), applying the paint (2), and drying the applied paint at a temperature of 140°C or less (3). In the coating step (2), the coating material is applied to a substrate by a known method. The substrate is not particularly limited, and examples thereof include inorganic materials, plastics, and paper. The method for applying the coating material to the substrate to be coated is not particularly limited, and various coaters may be used, such as a bar coater, comma coater, dip coater, roll coater, spin coater, flow coater, knife coater, and spray coater. After step (2), step (3) is carried out, in which the applied coating material is dried at a temperature of 140°C or lower. The drying temperature is preferably 120°C or lower, more preferably 100°C or lower. At such a drying temperature, the expansion of the thermally expandable graphite is easily suppressed. Step (3) removes the solvent (dispersion medium) in the coating material, and a sheet-like fire-resistant material is obtained. The sheet-like fire-resistant material can be peeled off from the coating substrate and used.

[0050] Alternatively, the fire-resistant material of the present invention is preferably produced by a method comprising the steps of producing a coating material by the above-mentioned step (1), then fluidizing and drying the coating material to form a powder (2'), and pressing the powder (3'). In the step (2') of fluidizing and powdering the paint, fluidized drying refers to drying performed while the paint is moving, preferably while stirring the paint. The paint can be stirred using a known mixing device, preferably a Loedige mixer, a fluidized bed dryer, or a Nauta mixer. The temperature during fluidized drying is, for example, 80 to 140°C, and preferably 90 to 120°C. After step (2'), the powder obtained in step (2') is pressed (step (3'). Known methods such as roll pressing and flat pressing can be used for the pressing, with roll pressing being preferred. The temperature during pressing is, for example, 60 to 120°C, and preferably 80 to 100°C.

[0051] In a refractory material produced by the manufacturing method including the above-mentioned steps (1), (2), and (3), or in a refractory material produced by the manufacturing method including the above-mentioned steps (1), (2'), and (3'), crushing of the thermally expandable graphite is suppressed, and therefore the thermal expandability of the thermally expandable graphite is well maintained. The refractory material obtained through such steps has excellent fire resistance and mechanical strength, a smooth surface, and good moldability.

[0052] <Laminated sheet> The fire-resistant material of the present invention may be laminated with other sheet members or pressure-sensitive adhesive layers to form a laminate sheet. The laminate sheet, for example, comprises a substrate and a fire-resistant material laminated on one or both sides of the substrate. The substrate is typically a woven fabric or nonwoven fabric. The fibers used in the woven fabric or nonwoven fabric are not particularly limited, but are preferably non-combustible or quasi-non-combustible materials, such as glass fiber, ceramic fiber, cellulose fiber, polyester fiber, carbon fiber, graphite fiber, and thermosetting resin fiber. The substrate may also be the coating substrate described above.

[0053] The laminated sheet may also include a fire-resistant material and an adhesive layer. The adhesive layer may be laminated on one or both sides of the fire-resistant material, for example. Furthermore, the laminate sheet may include a fire-resistant material, a substrate, and an adhesive layer. Such a laminate sheet may have the fire-resistant material on one side of the substrate and the adhesive layer on the other side, or the fire-resistant material and adhesive layer may be provided in this order on one side of the substrate. The adhesive layer can be formed, for example, by transferring an adhesive coated on release paper to the laminate sheet.

[0054] The fire-resistant material of the present invention and the laminate sheet using the same can be used specifically for various fittings in detached houses, apartment buildings, high-rise houses, high-rise buildings, commercial facilities, public facilities, etc., various vehicles such as automobiles and trains, ships, and aircraft, among others, but is preferably used for fittings. Specific examples of fittings that can be used include, but are not limited to, walls, beams, pillars, floors, bricks, roofs, boards, windows, shoji screens, doors, sliding doors, transoms, wiring, and piping. The fire-resistant material of the present invention and the laminate sheet using the same can be applied, particularly to gaps in fittings such as windows and doors, to prevent flames from penetrating through the gaps in the event of a fire or the like. [Example]

[0055] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0056] [Evaluation method] (1) Tensile elongation The tensile elongation is the elongation at break when the fire-resistant material is subjected to a tensile test at 23° C. using a tensile tester at a tensile speed of 20 mm / min.

[0057] (2) Expansion ratio The expansion ratio was measured by cutting the refractory material to a specified size (thickness 1.8 mm, width 25 mm, length 25 mm). The refractory material of the specified size was placed on the bottom of a stainless steel plate (98 mm square, thickness 0.3 mm), fed into an electric furnace, and heated at 600°C for 30 minutes. The expansion ratio was calculated by dividing the thickness of the refractory material after heating by the thickness of the refractory material before heating.

[0058] (3) Gradual temperature increase expansion ratio In the above (2), the refractory material was fed into an electric furnace, and the expansion ratio was determined when the temperature was increased from 20°C to 300°C at a rate of 5°C / min. The expansion ratio was determined by dividing the thickness of the refractory material when it reached 300°C by the thickness of the refractory material before the temperature increase.

[0059] (4) Thermal expansion residue hardness In the above (2), the test piece after heating for measuring the expansion ratio was fed to a compression tester (Finger Filling Tester manufactured by Kato Tech Co., Ltd.) and compressed to 0.25 cm 2 The specimen was compressed at a speed of 0.1 cm / sec with an indenter of 1000 kJ / cm2, and the breaking stress (kgf / cm2) was measured. 2 ) was measured and used as the thermal expansion residual hardness.

[0060] (5) Fire resistance time A door element for fire resistance evaluation was prepared, consisting of a door made of calcium silicate board (manufactured by Nippon Insulation Co., Ltd.) and a door frame. A 1 cm gap was left between the side of the door of the door element for fire resistance evaluation and the door frame. A fire-resistant material (thickness 1.8 mm, width 25 mm, length 1000 mm) of each example and comparative example cut to a predetermined size was attached to the side of the door. The door was then heated in a fire-resistant furnace according to the standard heating curve of ISO 834, and the time (minutes) until the fire-resistant material peeled off was measured. The longer the time until the fire-resistant material peeled off, the more excellent the fire resistance of the fire-resistant material.

[0061] (7) Formability The surface condition of the sheet-like molded products obtained in the examples and comparative examples was observed and evaluated according to the following criteria. The surface smoothness was excellent. △ The surface was smooth ×: The surface was poorly smooth.

[0062] The various components used in each of the examples and comparative examples are as follows. <NBR(1)> NBR (1) is an acrylonitrile butadiene rubber obtained by emulsion polymerization, with an acrylonitrile content of 28% by mass and a weight-average molecular weight (Mw) of 250,000. NBR (1) is contained in a polymer emulsion obtained by emulsion polymerization using water as a dispersion medium and the compounds listed in Table 1 as surfactants.

[0063] <NBR(2)> NBR (2) is an acrylonitrile butadiene rubber obtained by emulsion polymerization, with an acrylonitrile content of 28% by mass and a weight-average molecular weight of 70,000. NBR (2) is contained in a polymer emulsion obtained by emulsion polymerization using water as a dispersion medium and the compounds listed in Table 1 as surfactants.

[0064] <NBR(3)> NBR (3) is an acrylonitrile butadiene rubber obtained by emulsion polymerization, with an acrylonitrile content of 28% by mass and a weight-average molecular weight of 1.9 million. NBR (3) is contained in a polymer emulsion obtained by emulsion polymerization using water as a dispersion medium and the compounds listed in Table 1 as surfactants.

[0065] <NBR(4)> NBR (4) is an acrylonitrile butadiene rubber obtained by emulsion polymerization, with an acrylonitrile content of 33.5% by mass and a weight-average molecular weight of 250,000. NBR (4) is contained in a polymer emulsion obtained by emulsion polymerization using water as a dispersion medium and the compounds listed in Table 1 as surfactants.

[0066] <SBR(1)> SBR (1) is a styrene-butadiene rubber obtained by emulsion polymerization, with a styrene content of 23.5% by mass and a weight-average molecular weight of 250,000. SBR (1) is contained in a polymer emulsion obtained by emulsion polymerization using water as a dispersion medium and the compounds listed in Table 1 as surfactants.

[0067] <Chloroprene rubber (1)> Chloroprene rubber (1) is a chloroprene rubber obtained by emulsion polymerization and has a weight-average molecular weight of 250,000. Chloroprene rubber (1) is contained in a polymer emulsion obtained by emulsion polymerization using water as a dispersion medium and the compounds listed in Table 1 as surfactants.

[0068] <Polyvinyl acetate resin (1)> Polyvinyl acetate resin (1) is a polyvinyl acetate resin obtained by emulsion polymerization and has a weight-average molecular weight of 250,000. Polyvinyl acetate resin (1) is contained in a polymer emulsion obtained by emulsion polymerization using water as a dispersion medium and the compounds listed in Table 1 as surfactants.

[0069] <Ethylene-vinyl acetate copolymer (1)> The ethylene-vinyl acetate copolymer (1) is an ethylene-vinyl acetate copolymer obtained by emulsion polymerization, and has a vinyl acetate content of 23.5% by mass and a weight-average molecular weight of 250,000. The ethylene-vinyl acetate copolymer (1) is contained in a polymer emulsion obtained by emulsion polymerization using water as a dispersion medium and the compounds listed in Table 1 as surfactants.

[0070] In each example and comparative example, examples are shown in which fire-resistant materials containing the polymer compounds NBR (1) to (4), SBR (1), chloroprene rubber (1), polyvinyl acetate resin (1), and ethylene-vinyl acetate copolymer (1) were produced, and the above-mentioned polymer emulsions were used as raw materials.

[0071] <Ethylene-vinyl acetate copolymer (2)> Vinyl acetate content 23.5% by mass, weight average molecular weight 250,000, powder (non-emulsion polymerized product)

[0072] <Polyvinyl alcohol (1)> Powder with a saponification degree of 98 mol% and a weight average molecular weight of 45,000 (non-emulsion polymerized product)

[0073] <Thermal Expandable Graphite> Thermally expandable graphite "ADT351" manufactured by ADT Average aspect ratio: 21.3

[0074] <Flame retardant> Aluminum phosphite "APA100" manufactured by Taihei Chemical Industry Co., Ltd. Ammonium polyphosphate "AP422" manufactured by Clariant Chemicals

[0075] <Anionic surfactants> ·Sulfonate surfactants (1)··Sodium salt of formalin condensate of naphthalenesulfonic acid Sulfonate surfactants (2) Oleic acid ester sulfonate Sulfonate surfactants (3) Sodium laurate <Cationic surfactants> Stearyltrimethylammonium chloride

[0076] <Plasticizer> Polyethylene glycol: Daiichi Kogyo Seiyaku Co., Ltd. "PEG200"

[0077] Example 1 A paint was produced by mixing NBR (1), a polymer emulsion containing the surfactants and water listed in Table 1, thermally expandable graphite, a flame retardant, and a plasticizer using a mixer (Poafamx "Electric Mixer"). The amounts of each component were adjusted so that the content in the resulting fire-resistant material was as listed in Table 1. The coating material was applied to a coating substrate (release PET film) using a roll coater, and the applied coating material was dried at a drying temperature of 90°C to obtain a sheet-like fire-resistant material with a thickness of 1.8 mm. As shown in Table 1, the fire-resistant material contains 100 parts by mass of NBR(1), 120 parts by mass of thermally expandable graphite, 33 parts by mass of a flame retardant (aluminum phosphite), 1 part by mass of a surfactant (sodium salt of naphthalenesulfonic acid formalin condensate), and 30 parts by mass of a plasticizer (polyethylene glycol).

[0078] Example 2 A polymer emulsion containing NBR (1), a surfactant listed in Table 1, and water, thermally expandable graphite, a flame retardant, a plasticizer, and a surfactant listed in Table 1 were mixed using a mixer (Poafamx "Electric Mixer") to produce a paint. The amount of each component was adjusted so that the content in the resulting fire-resistant material would be as listed in Table 1. The coating material was applied to a substrate (a release PET film) using a roll coater, and the applied coating material was then dried at a drying temperature of 90°C to obtain a sheet-like fire-resistant material having a thickness of 1.8 mm.

[0079] (Examples 3 to 11, 13, and 14) A 1.8 mm thick sheet-shaped fire-resistant material was obtained in the same manner as in Example 1, except that a polymer emulsion containing the polymer compound, surfactant, and water, thermally expandable graphite, flame retardant, and plasticizer shown in Table 1 were used.

[0080] Example 12 A paint was produced by mixing NBR (1), a polymer emulsion containing the surfactants listed in Table 1, water, thermally expandable graphite, a flame retardant, and a plasticizer with a mixer. The amounts of each component were adjusted so that the content in the resulting fire-resistant material would be as listed in Table 1. The coating material was fluidized and dried in a Lödige mixer (Matsubo M20) at 95°C and 150 rpm to form a powder. The resulting powder was pressed in a hydraulic press at 100°C to obtain a 1.8 mm thick sheet-like fireproof material.

[0081] (Comparative Example 1) A 1.8 mm thick sheet-shaped fire-resistant material was obtained in the same manner as in Example 1, except that a coating material was produced by mixing an aqueous polyvinyl alcohol solution having a solids concentration of 20 mass % obtained by dissolving polyvinyl alcohol (1) in water at 95°C with thermally expandable graphite, a flame retardant, and a plasticizer shown in Table 1.

[0082] (Comparative Example 2) A 1.8 mm thick sheet-shaped fire-resistant material was obtained in the same manner as in Example 1, except that a polymer emulsion containing the polymer compound and surfactant shown in Table 1, thermally expandable graphite, a flame retardant, and a plasticizer were used.

[0083] (Comparative Example 3) A composition obtained by mixing ethylene-vinyl acetate copolymer (2), thermally expandable graphite, a flame retardant, and a plasticizer shown in Table 1 was extrusion-molded to obtain a sheet-shaped fire-resistant material having a thickness of 1.8 mm.

[0084] [Table 1]

[0085] The fire-resistant materials of each Example that satisfied the requirements of the present invention showed good results in all of the expansion ratio, gradual temperature-rising expansion ratio, thermal expansion residue hardness, and fire resistance time, and were excellent in fire resistance. Furthermore, the fire-resistant materials of each Example had high tensile elongation values, excellent mechanical strength, and also good formability. In contrast, the fire-resistant materials of each comparative example, which did not use an anionic surfactant, were found to be inferior in fire resistance, mechanical strength, and moldability compared to the fire-resistant materials of each example.

Claims

1. The adhesive composition contains at least one polymer compound selected from the group consisting of resins and rubbers, thermally expandable graphite, and an anionic surfactant, the polymer compound is at least one polymer prepared by emulsion polymerization selected from the group consisting of ethylene-vinyl acetate copolymer, polyvinyl acetate resin, acrylic resin, styrene-butadiene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, butadiene rubber, and natural rubber; A fire-resistant material for building materials, wherein the anionic surfactant contains a naphthalenesulfonic acid compound.

2. 2. The fire-resistant material according to claim 1, wherein the molecular weight of the polymer compound is 50,000 to 2,000,000.

3. The fireproof material according to claim 1 or 2, wherein the content of the anionic surfactant is 0.01 to 3 mass% based on the total amount of the fireproof material.

4. 4. The fire-resistant material according to claim 1, wherein the content of the thermally expandable graphite is 20 to 500 parts by mass per 100 parts by mass of the polymer compound.

5. The fire-resistant material according to any one of claims 1 to 4, wherein the polymer compound is an acrylonitrile butadiene rubber having an acrylonitrile content of 10 to 35 mass%.

6. The method for producing a fire-resistant material according to any one of claims 1 to 5, comprising a step (1) of producing a coating material containing a polymer emulsion containing an anionic surfactant and thermally expandable graphite.

7. 7. The method for producing a fire-resistant material according to claim 6, further comprising the steps of: (1) producing a paint; (2) applying the paint; and (3) drying the applied paint at a temperature of 140°C or less.

8. 7. The method for producing a fire-resistant material according to claim 6, further comprising the steps of: (1) producing a coating material; (2) fluidizing and drying the coating material to form a powder; and (3) pressing the powder.

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