JP2024035638A - Thermally expansible fireproof material - Google Patents

Abstract

To provide a thermally expansible fireproof material which has high strength in high-temperature expansion while having flexibility in a room-temperature environment.SOLUTION: A thermally expansible fireproof material contains a binder resin, a thermally expansible graphite, and an addition agent, wherein the addition agent contains a vulcanizer, tanδ at 200°C in dynamic viscoelasticity measurement is 0.8 or less, and tanδ at 25°C is 0.1 or more.SELECTED DRAWING: None

Description

The present invention relates to a thermally expandable refractory material containing thermally expandable graphite.

In the construction field, fireproof materials are used for building materials such as fittings, columns, and wall materials for fire prevention. As the fireproof material, a heat-expandable fireproof material in which heat-expandable graphite is blended with a resin in addition to a flame retardant, an inorganic filler, etc. is used (for example, see Patent Document 1). Such a thermally expandable refractory material expands upon heating, and combustion residue forms a fireproof heat insulating layer, thereby exhibiting fireproof heat insulating performance.
Thermal-expandable fireproofing materials containing thermally-expandable graphite are installed, for example, in gaps between fittings such as doors and sashes installed at openings in buildings (e.g., gaps between doors and door frames), and are used in the event of a fire. The sheet expands in the thickness direction to close the gap and prevent the spread of fire.

Patent Document 2 discloses a composition containing a rubber component, thermally expandable graphite, a vulcanizing agent, etc., which thermally expands after heating and closes the gaps in the structure to prevent the spread of fire and prevent combustion. It is stated that the resulting residue has sufficient shape retention.

Japanese Patent Application Publication No. 2013-130005 Japanese Patent Application Publication No. 2005-206648

Thermally expandable fireproofing materials containing vulcanizing agents have high residual strength after combustion and are excellent in fire resistance, but they have low flexibility at room temperature, are difficult to work with when pasted on fittings, etc., and are difficult to roll. There was room for improvement, such as cracks occurring during winding.
Therefore, the present invention aims to provide a thermally expandable refractory material containing a vulcanizing agent that has flexibility at room temperature and has residual strength after expansion in a high temperature environment (hereinafter also referred to as strength at high temperature expansion). ) aims to provide a refractory material with high thermal expansion.

The present inventors have made extensive studies to solve the above problems. As a result, it was found that a thermally expandable fireproof material containing a binder resin, thermally expandable graphite, and an additive, where the additive includes a vulcanizing agent, has a tan δ of 0.8 at 200°C in dynamic viscoelasticity measurement. It has been found that the above-mentioned problems can be solved by a thermally expandable refractory material having a tan δ of 0.1 or more at 25° C., and the present invention has been completed.
That is, the present invention relates to the following [1] to [8].
[1] A thermally expandable fireproof material containing a binder resin, thermally expandable graphite, and additives,
Thermal expandability, wherein the additive includes a vulcanizing agent, and the thermally expandable refractory material has a tan δ of 0.8 or less at 200°C and a tan δ of 0.1 or more at 25°C in dynamic viscoelasticity measurement. Fireproof material.
[2] The thermally expandable refractory material according to [1] above, which has an expansion ratio in the thickness direction of 3 times or more when heated at 400° C. for 20 minutes.
[3] The thermally expandable fireproof material according to [1] or [2] above, wherein the binder resin contains a rubber component.
[4] The thermally expandable fireproof material according to any one of [1] to [3] above, wherein the binder resin does not contain halogen in its molecular structure.
[5] The thermally expandable fireproof material according to any one of [1] to [4] above, wherein the binder resin contains a nitrile group.
[6] The thermally expandable refractory material according to any one of [1] to [5] above, comprising a surface layer material that does not contain thermally expandable graphite.
[7] The thermally expandable fireproof material according to [6] above, wherein the binder resin contained in the surface layer material does not contain halogen in its molecular structure.
[8] The thermally expandable fireproof material according to any one of [1] to [7] above, which is used as a fireproofing member for fireproof doors and sashes.

According to the present invention, it is possible to provide a thermally expandable refractory material that is flexible at room temperature and has high strength when expanded at high temperatures.

[Thermally expandable fireproof material]
The heat-expandable fire-resistant material of the present invention is a heat-expandable fire-resistant material containing a binder resin, heat-expandable graphite, and an additive, the additive containing a vulcanizing agent, and the heat-expandable fire-resistant material containing The tan δ at 200°C in dynamic viscoelasticity measurement is 0.8 or less, and the tan δ at 25°C is 0.1 or more. Hereinafter, the thermally expandable refractory material of the present invention may be simply referred to as a refractory material.
The fireproof material of the present invention includes at least an expansion layer containing a binder resin, thermally expandable graphite, and an additive. The thermally expandable fireproofing material may be comprised only of an expansion layer, or may include a surface layer material and an adhesive layer in addition to the expansion layer, as described below.

(tan δ at 200°C and 25°C)
The refractory material of the present invention has a tan δ (loss tangent) of 0.8 or less at 200° C. in dynamic viscoelasticity measurement. If the tan δ at 200° C. of the refractory material exceeds 0.8, the strength during high temperature expansion will be low and the fire resistance will decrease. From the viewpoint of increasing strength during high-temperature expansion and improving fire resistance, the tan δ at 200° C. of the refractory material is preferably 0.7 or less, more preferably 0.6 or less. Further, from the viewpoint of shape followability against deformation of fittings during high-temperature expansion, the tan δ of the refractory material at 200° C. is preferably 0.2 or more, more preferably 0.3 or more.

The fireproof material of the present invention has a tan δ of 0.1 or more at 25° C. in dynamic viscoelasticity measurement. If the tan δ at 25°C of the refractory material is less than 0.1, the flexibility at room temperature (25°C) will decrease, making it difficult to work when pasting it on fittings, etc., and making it difficult to wind it into a roll. cracks are more likely to occur. From the viewpoint of improving flexibility at room temperature, the tan δ of the refractory material at 25° C. is preferably 0.15 or more, more preferably 0.2 or more. Further, from the viewpoint of ensuring a constant mechanical strength at room temperature, the tan δ of the refractory material at 25° C. is preferably 1.0 or less.
The tan δ of the refractory material at 200° C. and 25° C. can be adjusted to a desired value depending on the composition and manufacturing method of the refractory material.
The tan δ of the refractory material can be measured by a tensile method using a dynamic viscoelasticity measuring device under conditions of a frequency of 10 Hz and a heating rate of 5° C./min.

(Expansion magnification)
The expansion ratio of the refractory material of the present invention is preferably 3 times or more. If the expansion ratio of the fireproof material is less than 3 times, it will be difficult to close gaps between fittings in the event of a fire, making it difficult to prevent the spread of fire.
The expansion ratio of the refractory material of the present invention is preferably 5 times or more, more preferably 6 times or more, and even more preferably 7 times or more, from the viewpoint of making it easier to close the gap. In addition, from the viewpoint of conformability to fittings in the event of a fire, the expansion ratio of the thermally expandable fireproof material of the present invention is preferably 15 times or less, more preferably 12 times or less, and still more preferably 10 times or less. It is.

The expansion ratio of the refractory material of the present invention is the expansion ratio in the thickness direction when a refractory material cut into a size (width x length) of 50 mm x 50 mm is heated at 400°C for 20 minutes, and the thickness of the refractory material after heating is It can be determined by dividing the thickness by the thickness of the refractory material before heating.
The expansion ratio can be adjusted by the types and amounts of thermally expandable graphite, binder resin, vulcanizing agent, and plasticizer blended as necessary.

The fireproof material of the present invention includes an expansion layer containing a binder resin, thermally expandable graphite, and additives. The composition of the refractory material will be explained below.

(binder resin)
The binder resin includes, for example, at least one selected from resins and rubber components. Among these, it is preferable that the binder resin contains a rubber component.
Moreover, it is preferable that the binder resin does not contain halogen in its molecular structure. By using a binder resin that does not contain halogen, it is possible to suppress corrosion of various members for which the refractory material is used.

<Rubber component>
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), and ethylene-propylene. Examples include 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. Furthermore, among these rubber components, those that do not contain halogen are preferred from the viewpoint of suppressing corrosion of various members using fireproof materials, and the rubber components are selected from styrene-butadiene rubber, acrylonitrile rubber-butadiene rubber, and butadiene rubber. At least one selected from the group consisting of:

Moreover, it is preferable that the binder resin contains a nitrile group. By using a binder resin containing a nitrile group, it becomes easier to increase the strength of the residue after expansion of the refractory material, and the fire resistance improves. Examples of the binder resin containing a nitrile group include homopolymers of acrylonitrile and copolymers of acrylonitrile and other compounds having ethylenically unsaturated bonds, and among them, acrylonitrile-butadiene rubber is preferred.
One type of binder resin may be used alone, or two or more types may be used in combination.

The amount of nitrile in 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. A fireproof material containing an acrylonitrile-butadiene rubber having a nitrile content in the above range has good flexibility, and when used in combination with a plasticizer described below, the flexibility can be further increased and the handleability can be improved.
The Mooney viscosity ML (1+4) at 100° C. of the acrylonitrile-butadiene rubber is preferably 20 to 90, more preferably 25 to 80, even more preferably 30 to 70. A fireproof material containing acrylonitrile-butadiene rubber having a Mooney viscosity ML (1+4) at 100° C. within the above range can easily secure adhesion to various members such as fittings, and improve followability to the member. It is also preferable to use two or more types of acrylonitrile butadiene rubbers having different Mooney viscosities ML (1+4) at 100°C.
Note that in this specification, Mooney viscosity is measured in accordance with JIS K6300.

Since chloroprene rubber can lower the proportion of carbon contained in the refractory material, it is also preferable to use chloroprene rubber as the rubber contained in the refractory material from the viewpoint of increasing fire resistance.
As the 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 the chloroprene rubber at 100° C. is preferably 20 to 120, more preferably 30 to 90, from the viewpoint of improving followability to the refractory material member.

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 the styrene-butadiene rubber at 100° C. is preferably from 20 to 60, more preferably from 30 to 55, even more preferably from 40 to 50, from the viewpoint of flexibility.

The butadiene rubber is not particularly limited, but from the viewpoint of flexibility, the Mooney viscosity ML (1+4) at 100° C. is preferably 20 to 60, more preferably 30 to 55.

<Resin>
The resin may be a thermosetting resin or a thermoplastic resin, but preferably a thermoplastic resin. Thermoplastic resins are not particularly limited, but include, for example, polyolefin resins such as polypropylene resins and polyethylene resins, fluororesins such as ethylene-vinyl acetate copolymers, polyvinyl acetate resins, polyvinyl chloride resins, and polytetrafluoroethylene; Examples include urethane resins such as phenol resins, polycarbonate resins, polyacrylonitrile resins, and urethane elastomers.

The content of the binder resin contained in the expansion layer of the fireproof material is not particularly limited, but is, for example, 20 to 90% by mass, preferably 30 to 80% by mass, more preferably 30 to 80% by mass, based on the total amount of the expansion layer. It is 40 to 70% by mass.

(thermal expandable graphite)
The expansion layer in 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 made by acid-treating raw material powders such as natural scale graphite, pyrolytic graphite, and quiche graphite with a strong oxidizing agent to generate graphite intercalation compounds. be. 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 a carbon layered structure.
Thermally expandable graphite may be neutralized. That is, the thermally expandable graphite obtained by treating with a strong oxidizing agent 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.

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, based on 100 parts by mass of the binder resin. It is. When the content of thermally expandable graphite is equal to or higher than these lower limits, it becomes easier to increase the expansion pressure of the thermally expandable refractory material, and it becomes easier to adjust the expansion ratio to a desired range. On the other hand, when the content of thermally expandable graphite is below these upper limits, the strength of the refractory material when expanded at high temperatures increases.

The thermally expandable graphite in the present 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 equal to or higher than these lower limits, the expansion pressure of the refractory material can be easily increased.
The aspect ratio of thermally expandable graphite is determined by measuring the maximum dimension (major axis) and minimum dimension (minor axis) of 10 or more pieces of thermally expandable graphite (for example, 50 pieces), and calculating the ratio of these (maximum dimension / (minimum dimension).

The average particle size of the thermally expandable graphite is preferably 50 to 500 μm, more preferably 100 to 400 μm. The average particle size of the thermally expandable graphite is determined as the average value of the maximum size of 10 or more (for example, 50) thermally expandable graphites.
The minimum and maximum dimensions of the thermally expandable graphite described above can be measured using, for example, a field emission scanning electron microscope (FE-SEM).

(vulcanizing agent)
The additive contained in the expansion layer of the refractory material of the present invention contains a vulcanizing agent. In particular, when using a rubber component as a binder resin, containing a vulcanizing agent increases the elasticity of the refractory material when it expands, improves the strength of the expanded refractory material residue, and prevents it from falling off from various parts. It becomes easier to suppress things.
As the vulcanizing agent, any known vulcanizing agent can be used without limitation, and examples thereof include sulfur compounds, organic peroxides, azo compounds, and the like.
The sulfur compound may be an inorganic compound such as sulfur, insoluble sulfur, precipitated sulfur, sulfur chloride, sulfur monochloride, or sulfur dichloride, or may be a sulfur-containing organic crosslinking agent. Examples of the sulfur-containing organic crosslinking agent include morpholine disulfide, alkylphenol disulfide, N,N'-dithio-bis(hexahydro-2H-azepinone-2), thiuram polysulfide, 2-(4'-morpholino dithio)benzothiazole, etc. It will be done.
Examples of organic peroxides include 2,5-dimethylhexane, 2,5-dihydroperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 3-di-t -butyl peroxide, t-dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne, dicumyl peroxide, α,α'-bis(t-butylperoxyisopropyl) ) Benzene, n-butyl-4,4-bis(t-butylperoxy)butane, 2,2-bis(t-butylperoxy)butane, 1,1-bis(t-butylperoxy)cyclohexane, 1 , 1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane, t-butylperoxybenzoate: benzoylperoxide: t-butylperoxy-2-ethylhexyl carbonate, and the like.
Examples of the azo compound include azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile).
The vulcanizing agents may be used alone or in combination of two or more.

In addition, among the above-mentioned vulcanizing agents, when manufacturing fireproof materials, crosslinking reactions are difficult to occur at the temperature at which each component is kneaded, and the crosslinking reaction of rubber components such as acrylonitrile-butadiene rubber is inhibited by the heat of a fire. Those that easily occur are preferred. Specifically, sulfur-based compounds are preferred, and among these, inorganic compounds are preferred from the viewpoint of crosslinking properties, and sulfur is more preferred.
When the fireproof material contains a vulcanizing agent, the content of the vulcanizing agent is preferably 0.1 to 10 parts by mass, more preferably 0.2 to 5 parts by mass, based on 100 parts by mass of the binder resin. parts, more preferably 0.5 to 3 parts by mass.

(vulcanization aid)
The additives contained in the intumescent layer of the present invention may include a vulcanization aid in addition to the vulcanizing agent. Examples of vulcanization aids include metal oxides such as zinc oxide and magnesium oxide, thiazole compounds, sulfenamide compounds, sulfamide compounds, thiuram compounds, dithiocarbamate compounds, guanidine compounds, and thiourea compounds. Examples include compounds. The vulcanization aids may be used alone or in combination of two or more. Among these, sulfamide compounds are preferred.
When a vulcanization aid is used in the fireproof material of the present invention, the amount of the vulcanization aid is not particularly limited, but is preferably 0.1 to 15 parts by mass based on 100 parts by mass of the binder resin. The amount is more preferably 0.2 to 10 parts by weight, and even more preferably 0.3 to 8 parts by weight.

(Flame retardants)
The additive in the present invention preferably contains a flame retardant. Containing a flame retardant improves fire resistance.
Examples of flame retardants include various phosphoric acid esters such as triphenyl phosphate (triphenyl phosphate), tricresyl phosphate, tricylenyl phosphate, cresyl diphenyl phosphate, and xylenyl diphenyl phosphate, sodium phosphate, and phosphoric acid. Potassium acid, metal phosphates such as magnesium phosphate, metal salts of phosphites such as sodium phosphite, potassium phosphite, magnesium phosphite, aluminum phosphite, ammonium polyphosphate, red phosphorus, etc. It will be done. Examples of the flame retardant include compounds represented by the following general formula (1).

In the general formula (1), R ¹ and R ³ are the same or different and represent hydrogen, a linear or branched alkyl group having 1 to 16 carbon atoms, or an aryl group having 6 to 16 carbon atoms. R ² is 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 a carbon number Indicates 6 to 16 aryloxy groups.

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, and 2-methylpropylphosphonic acid. , t-butylphosphonic acid, 2,3-dimethyl-butylphosphonic acid, octylphosphonic acid, phenylphosphonic acid, dioctyl phenylphosphonate, 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.

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

Among the flame retardants, red phosphorus, phosphate esters such as triphenyl phosphate (triphenyl phosphate), aluminum phosphite, ammonium polyphosphate, and zinc borate are preferable from the viewpoint of safety and cost. Among these, aluminum phosphite and ammonium polyphosphate are more preferred.
In addition, the flame retardants listed above may be used alone or in combination of two or more types, but it is preferable to use one type alone. More preferably, aluminum is used. Since aluminum phosphite has expansibility, the expansion pressure of a fireproof material containing it tends to increase, making it easier to improve fire resistance more effectively.

The average particle diameter 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 fireproof material will improve, and the flame retardant can be uniformly dispersed in the binder resin, and the amount of flame retardant added to the binder resin can be increased. You can Moreover, when the average particle diameter is outside the above range, it becomes difficult to disperse the flame retardant in the binder resin, and it becomes difficult to uniformly disperse the flame retardant in the binder resin or to mix it in a large amount.
Note that the average particle diameter of the flame retardant is the value of the median diameter (D50) measured by a laser diffraction/scattering particle size distribution analyzer.

The content of the flame retardant in the present invention is preferably 1 to 500 parts by weight, more preferably 3 to 100 parts by weight, and even more preferably 5 to 50 parts by weight, based on 100 parts by weight of the binder resin.
When the content of the flame retardant is equal to or higher than these lower limits, the fire resistance of the refractory material improves. Moreover, when the content of the flame retardant is below these upper limits, it becomes easier to disperse uniformly in the resin, resulting in excellent moldability.

(Plasticizer)
The additive in the present invention preferably contains a plasticizer. By using a plasticizer, flexibility at room temperature can be easily improved.
Examples of the plasticizer include, but are not limited to, phthalic acid plasticizers, adipic acid plasticizers, phosphoric acid plasticizers, alkylsulfonic acid plasticizers, and the like.

Examples of the phthalic acid plasticizer include di-2-ethylhexyl phthalate (DOP), di-n-octyl phthalate, diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), diundecyl phthalate (DUP), or carbon atoms Examples include phthalate esters of higher alcohols or mixed alcohols having a molecular weight of about 10 to 13.
Examples of adipic acid 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, adipic acid polyester, and the like.

Examples of phosphoric acid plasticizers include trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, octyldiphenyl phosphate, tributoxyethyl phosphate, trichloroethyl phosphate, tris(2-chloropropyl) phosphate, and tris(2-chloropropyl) phosphate. , 3-dichloropropyl) phosphate, tris(2,3-dibromopropyl) phosphate, tris(bromochloropropyl) phosphate, bis(2,3-dibromopropyl)-2,3-dichloropropyl phosphate, bis(chloropropyl) Examples include monooctyl phosphate, tris(2-ethylhexyl) phosphate, triphenyl phosphate, tricresyl phosphate (TCP), tricylenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, and the like.
Examples of the alkylsulfonic acid plasticizer include alkylsulfonic acid phenyl ester, N-butylbenzenesulfonamide, and the like.

Among the above-mentioned plasticizers, adipic acid plasticizers or alkyl sulfonic acid plasticizers are preferred. Among them, when using a rubber component as a binder resin, alkyl sulfonic acid More preferred are plasticizers. Furthermore, among the alkylsulfonic acid plasticizers, alkylsulfonic acid phenyl esters are more preferred.

When using a plasticizer, the content of the plasticizer is not particularly limited, but is preferably 5 to 100 parts by weight, more preferably 10 to 60 parts by weight, based on 100 parts by weight of the binder resin. More preferably, it is 15 to 40 parts by mass.
By adjusting the content of the plasticizer within the above range, it becomes easier to adjust the tan δ of the refractory material to a desired range.

(Inorganic filler)
The additive in the present invention may further contain a flame retardant and an inorganic filler other than thermally expandable graphite.
Inorganic fillers other than flame retardants and thermally expandable graphite are not particularly limited, and include metal carbonates such as alumina, basic magnesium carbonate, calcium carbonate, magnesium carbonate, zinc carbonate, strontium carbonate, and barium carbonate, and silica. , diatomaceous earth, dawsonite, barium sulfate, talc, clay, mica, montmorillonite, bentonite, activated clay, sepiolite, imogolite, sericite, glass fiber, glass beads, silica balloon, aluminum nitride, boron nitride, silicon nitride, carbon black, Graphite, carbon fiber, carbon balloon, charcoal powder, various metal powders, potassium titanate, magnesium sulfate, lead zirconate titanate, aluminum borate, molybdenum sulfide, silicon carbide, stainless steel fiber, various magnetic powders, slag fiber, fly ash, and dehydrated sludge. These inorganic fillers may be used alone or in combination of two or more.

The average particle diameter of the inorganic filler is preferably 0.5 to 100 μm, more preferably 1 to 50 μm. When the content is low, the inorganic filler preferably has a small particle size from the viewpoint of improving dispersibility, and when the content is high, the viscosity of the refractory material increases and the moldability decreases as the filling progresses. Therefore, particles with a large particle size are preferable.

When the fireproof material of the present invention contains an inorganic filler other than flame retardant and thermally expandable graphite, the content thereof is preferably 10 to 300 parts by mass, more preferably 10 to 300 parts by mass, based on 100 parts by mass of binder resin. It is 200 parts by mass. When the content of the inorganic filler is within the above range, the mechanical properties of the refractory material can be improved.

The refractory material of the present invention can contain various additive components as necessary within a range that does not impair the object of the present invention.
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, gelling promoters, and fillers. , reinforcing agents, flame retardant aids, antistatic agents, surfactants, and surface treatment agents. The amount of additives to be added can be appropriately selected within a range that does not impair moldability or the like. The additives may be used alone or in combination of two or more.

Further, from the viewpoint of fire resistance, the fireproof material of the present invention has a residual strength after thermal expansion of preferably 0.3 kgf/cm ² or more, more preferably 0.5 kgf/cm ² or more, and still more preferably 0.7 kgf/cm 2 or more. /cm ² or more, more preferably 0.8 kgf/cm ² or more. The above-mentioned residual strength is preferably 2.0 kgf/cm ² or less, more preferably 1.5 kgf/cm ² or less, from the viewpoint of ensuring fire resistance by making the refractory material easy to expand. Note that the residual strength can be measured by the method described in Examples.

(thickness)
The expansion layer of the fireproof material of the present invention is preferably in the form of a sheet, and its thickness is not particularly limited, but from the viewpoint of fire resistance and handleability, it is preferably 0.2 to 10 mm, and 0.5 to 3 mm. .0 mm is more preferable.

(Method for manufacturing 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, a binder resin, a vulcanizing agent, a plasticizer, a flame retardant, an inorganic filler, and other components blended as necessary are kneaded using a kneading machine such as a kneading roll. A fire-resistant resin composition is obtained.
Next, the expanded layer can be obtained by molding the obtained fire-resistant resin composition into a sheet shape or the like by a known molding method such as press molding, calendar molding, extrusion molding, or the like.
The kneading temperature and the sheet-forming temperature are preferably lower than the expansion start temperature of thermally expandable graphite, and are preferably temperatures at which the vulcanizing agent is difficult to crosslink. Therefore, the kneading temperature is preferably 40 to 100°C, more preferably 50 to 80°C. The temperature for forming into a sheet is preferably 70 to 110°C, more preferably 80 to 100°C.
As described above, by adjusting the temperature when kneading each component and the temperature when forming into a sheet, it is easy to adjust the tan δ at 200°C and tan δ at 25°C of the refractory material to desired values. Become.

(layers other than the expansion layer)
The fireproof material of the present invention may be composed of only the expansion layer, but may also have layers other than the expansion layer, such as a surface layer material and an adhesive layer, which will be described below.

(Surface material)
In the refractory material of the present invention, a surface layer material may be provided on one or both surfaces of the expansion layer from the viewpoint of improving the appearance and improving the scratch resistance. The surface layer material is a resin layer containing binder resin. The surface layer material may contain the above-mentioned flame retardant, plasticizer, inorganic filler, etc. in addition to the binder resin, or may be composed only of the binder resin.
The binder resin of the surface layer material is not particularly limited, but from the viewpoint of suppressing corrosion of various members using fireproof materials, it is preferable that the binder resin does not contain halogen in its molecular structure.

The type of binder resin in the surface layer material is not particularly limited, but includes polyester resins such as polyethylene terephthalate, polyolefin resins such as polyethylene and polypropylene, rubber-based resins such as acrylonitrile rubber-butadiene rubber, styrene-butadiene rubber, butadiene rubber, and chloroprene rubber. Examples include resin, polyvinyl chloride resin, and the like.
The surface layer material is preferably a layer that does not contain thermally expandable graphite. Therefore, in a fireproof material including a surface layer material, in the event of a fire, the expansion layer expands in the plane and thickness direction, and the surface layer material does not expand, so generally the surface layer material is covered by the expanded expansion layer.
The thickness of the surface layer material is, for example, 5 to 1000 μm, preferably 5 to 500 μm.

(Adhesive layer)
The fireproof material of the present invention may have an adhesive layer on one or both surfaces of the expansion layer from the viewpoint of making it easier to attach to various members. The adhesive layer is not particularly limited and may use a commonly used adhesive, for example, an acrylic adhesive may be used.
The thickness of the adhesive layer is, for example, 10 to 500 μm, preferably 50 to 300 μm.
Moreover, the fireproof material may have both an adhesive layer and a surface layer material. In this case, it is preferable to use a fireproof material having an adhesive layer on one side of the expansion layer and a surface layer material on the other side.

(Application)
Specifically, the fireproof material of the present invention can be used for various types of fittings such as single-family houses, apartment complexes, high-rise residences, high-rise buildings, commercial facilities, and public facilities, various vehicles such as automobiles and trains, ships, aircraft, etc. However, among these, it is preferable to use it for fittings. As for fittings, specifically, it can be used for walls, beams, columns, floors, bricks, roofs, boards, sashes, shoji, doors, fire doors, doors, sliding doors, transoms, wiring, piping, etc. Preferably used in fire doors or sashes. The fireproof material of the present invention has good expansion characteristics that can close gaps, and easily follows the deformation of members in the event of a fire. Therefore, it can be particularly applied to gaps in fire doors or sashes, and used as a fireproofing member. preferable.

The present invention will be described in more detail with reference to Examples below, but the present invention is not limited thereto.

[Evaluation method]
(1) Expansion magnification The refractory materials of each example and comparative example were made to a predetermined size (width 50 mm, length 50 mm). The refractory material of the predetermined size was placed on the bottom of a stainless steel plate (98 mm square, 0.3 mm thick), and the refractory material was placed in an electric furnace preset at 400°C. Heated for a minute. The expansion ratio was determined by dividing the thickness of the refractory material after heating by the thickness of the refractory material before heating.

(2) Residual strength The expanded layer of the refractory material expanded by the expansion ratio test described above was used as a test piece, and a compression tester (Finger Filling Tester manufactured by Kato Tech) was used to measure 0.1 cm/2 with a 0.25 cm ² indenter. The sample was compressed at a speed of 1 second, and the stress at break was measured, which was defined as the residual strength (kgf/cm ² ).

(3) Flexibility When a 50mm x 500mm refractory material is wrapped around a 3-inch paper core and stored at 25℃ for one day, if no lifting occurs between the core and the refractory material or between the refractory material and the refractory material, Good flexibility was rated as "○", and if lifting occurred, flexibility was poor and rated as "x".

(4) Corrosion The fireproof material was cut into dimensions (width x length) of 25 mm x 25 mm. Two SUS plates (stainless steel plates) were prepared and placed using spacers so as to face each other at an interval three times the thickness of the refractory material. Then, the fireproof material was attached to the surface of one of the SUS plates using an acrylic adhesive to produce a structure. The structure was heated in an electric furnace at 600° C. for 20 minutes to expand the refractory material. Thereafter, the expanded refractory material was removed, and the SUS plate surface was visually observed and evaluated based on the following criteria.
<Evaluation>
○: Corrosion was not confirmed.
×: Corrosion was confirmed.

(5) tan δ at 25°C and 200°C
The value of tan δ (loss tangent) in dynamic viscoelasticity measurement of the refractory material at 25° C. and 200° C. was measured using a dynamic viscoelasticity measuring device (“DMS6100” manufactured by SII Nanotechnology Co., Ltd.). The measurement was performed using a tensile method at a frequency of 10 Hz and a heating rate of 5° C./min.

The various components used in each example and comparative example are as follows.
(binder resin)
・NBR (high viscosity) acrylonitrile-butadiene rubber, “Nipol DN401” manufactured by Nippon Zeon, Mooney viscosity ML (1+4) 100°C: 77.5, nitrile content 18% by mass
・NBR (medium viscosity) acrylonitrile-butadiene rubber, “Nipol DN401L” manufactured by Nippon Zeon, Mooney viscosity ML (1+4) 100°C: 65, nitrile content 18% by mass
・NBR (low viscosity) acrylonitrile-butadiene rubber, “Nipol DN101LL” manufactured by Nippon Zeon, Mooney viscosity ML (1+4) 100°C: 32, nitrile content 18% by mass
・NBR (medium NT) acrylonitrile-butadiene rubber, “NipolDN302” manufactured by Nippon Zeon, Mooney viscosity ML (1+4) 100°C: 62.5, nitrile content 27.5% by mass
・CR chloroprene rubber, “M-40” manufactured by Denka, Mooney viscosity ML (1+4) 100°C: 46
・BR Butadiene rubber, “Nipol BR1220” manufactured by Nippon Zeon, Mooney viscosity ML (1+4) 100°C: 44
・SBR styrene-butadiene rubber, “Nipol1723” manufactured by Nippon Zeon, Mooney viscosity ML (1+4) 100°C: 47

(Flame retardants)
・Aluminum phosphite “APA100” manufactured by Taihei Kagaku Sangyo Co., Ltd.

(Plasticizer)
・Alkylsulfonic acid-based alkylsulfonic acid phenyl ester, “Mesamoll” manufactured by LANXESS

(vulcanizing agent)
・Sulfur-based “Colloidal Sulfur” manufactured by Hosoi Chemical Industry
・Peroxide type (peroxide type), "Perc Mill D" manufactured by NOF Corporation

(vulcanization aid)
・Sulfamide compound, “Accel CZ” manufactured by Kawaguchi Chemical Industry Co., Ltd.

(thermal expandable graphite)
・Thermally expandable graphite 1 “ADT351” manufactured by ADT, expansion start temperature 170°C
・Thermally expandable graphite 2 “EXP42S160” manufactured by Fuji Graphite Industries Co., Ltd., expansion start temperature 160°C

(Example 1)
In the formulation shown in Table 1, each component for forming the expansion layer was kneaded using a plastomill at 60° C. for 5 minutes to obtain a fire-resistant resin composition. The obtained fire-resistant resin composition was press-molded at 90° C. for 3 minutes to obtain a fire-resistant material consisting of a sheet-like expansion layer with a thickness of 1.5 mm. The evaluation results are shown in Table 1.

(Examples 2 to 12, Comparative Examples 1 to 2)
A refractory material was obtained in the same manner as in Example 1, except that the blending and kneading temperature were changed as shown in Table 1. The evaluation results are shown in Table 1.

The refractory materials of each example had a good evaluation of flexibility and a high value of residual strength. This shows that the refractory material of the present invention has excellent flexibility at room temperature and high strength when expanded at high temperatures.
On the other hand, the refractory materials of each comparative example had poor flexibility evaluations or low residual strength values, so they were unable to achieve both flexibility at room temperature and strength at high temperature expansion. Ta.

Claims (8)

A thermally expandable fireproof material containing a binder resin, thermally expandable graphite, and an additive,
the additive includes a vulcanizing agent,
The thermally expandable refractory material has a tan δ of 0.8 or less at 200°C and a tan δ of 0.1 or more at 25°C in a dynamic viscoelasticity measurement of the thermally expandable refractory material. The thermally expandable refractory material according to claim 1, having an expansion ratio in the thickness direction of 3 times or more when heated at 400° C. for 20 minutes. The thermally expandable fireproof material according to claim 1 or 2, wherein the binder resin contains a rubber component. The thermally expandable fireproof material according to claim 1 or 2, wherein the binder resin does not contain halogen in its molecular structure. The thermally expandable fireproof material according to claim 1 or 2, wherein the binder resin contains a nitrile group. The thermally expandable fireproof material according to claim 1 or 2, comprising a surface layer material that does not contain thermally expandable graphite. The thermally expandable fireproof material according to claim 6, wherein the binder resin contained in the surface layer material does not contain halogen in its molecular structure. The thermally expandable fireproof material according to claim 1 or 2, which is used as a fireproofing member for fireproof doors and sashes.