Thermally expandable composition and thermally expandable fireproof sheet

Abstract

To provide a thermally expandable composition and a thermally expandable fireproof sheet which can maintain good fire resistance even if warping of fire protective equipment occurs in the case of fire.SOLUTION: There is provided a thermally expandable composition which comprises a matrix component, thermally expandable graphite and an inorganic filler containing a heat absorbing agent, wherein the difference between the expansion start temperature X of the thermally expandable graphite and the heat absorption start temperature Y of the heat absorbing agent is within 100°C and the decomposition start temperature Z of the matrix component is equal to or higher than the expansion start temperature X and the heat absorption start temperature Y.SELECTED DRAWING: None

Description

[Technical field]

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

[0002] In the field of construction, fireproof materials are used in fireproof equipment such as doors and windows. Examples of fireproof materials include fireproof sheets made of resin mixed with inorganic fillers and thermally expandable graphite (see, for example, Patent Document 1). Such fireproof sheets expand when heated, and the combustion residue forms a fireproof insulation layer, thereby exhibiting fireproof insulation performance. Specifically, fireproof sheets are provided in the gaps between doors and windows and the frames surrounding them, such as door frames and window frames, and in the event of a fire, the sheet expands in the thickness direction to close the gap and prevent the fire from spreading. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-141463 A Summary of the Invention [Problem to be solved by the invention]

[0004] When fire prevention equipment such as doors and windows are exposed to high temperatures for long periods of time during a fire, a temperature difference occurs between the heated and non-heated surfaces, causing the equipment to warp and deform. This warping can cause the heated and non-heated surfaces that were previously sealed to become penetrated, resulting in the spread of the fire. Therefore, an object of the present invention is to provide a thermally expandable composition and a thermally expandable fire-resistant sheet that can maintain good fire resistance even if warping occurs in a fire prevention facility during a fire. [Means for solving the problem]

[0005] The present inventors have conducted extensive research and have found that the above-mentioned problems can be solved by a thermally expandable composition that contains a matrix component, thermally expandable graphite, and a heat absorbing agent, in which the difference between the expansion start temperature X of the thermally expandable graphite and the endothermic start temperature Y of the endothermic agent is within 100° C., and the decomposition temperature Z of the matrix component is equal to or higher than the expansion start temperature X and the endothermic start temperature Y, and thus the present invention has been completed. That is, the present invention provides the following [1] to

[12] .

[0006] [1] A thermally expandable composition comprising a matrix component, thermally expandable graphite, and a heat-absorbing agent, wherein a difference between an expansion onset temperature X of the thermally expandable graphite and an endothermic onset temperature Y of the endothermic agent is within 100°C, and a decomposition onset temperature Z of the matrix component is equal to or higher than the expansion onset temperature X and the endothermic onset temperature Y. [2] The thermally expandable composition according to the above [1], containing 3 to 300 parts by mass of thermally expandable graphite and 2 to 200 parts by mass of an inorganic filler relative to 100 parts by mass of a matrix component, and a content of the heat-absorbing agent in the inorganic filler is 5 mass% or more. [3] A thermally expandable fire-resistant sheet obtained by molding the thermally expandable composition according to [1] or [2] above. [4] The heat-expandable fire-resistant sheet according to [3] above, having an expansion start temperature of 160°C or lower. [5] The heat-expandable fire-resistant sheet according to [3] or [4] above, which has a dissolution rate of 3% or less after immersion in pure water at 60°C for one week. [6] The thermally expandable fire-resistant sheet according to any one of the above [3] to [5], wherein the matrix component does not contain a phosphorus component. [7] The heat-expandable fire-resistant sheet according to any one of the above [3] to [6], which has a substrate or an adhesive layer on at least one surface. [8] The heat-expandable fire-resistant sheet according to any one of the above [3] to [7], which is a rolled body having a length of 1 m or more. [9] The heat-expandable fire-resistant sheet according to any one of [3] to [8] above, having a length of 1 m or more, a thermal shrinkage rate of 1% or less in both the MD and TD directions, a thickness of 0.5 mm or more, and a thickness variation of 0.1 mm or less.

[10] A method for producing a thermally expandable fire-resistant sheet, comprising solidifying, drying, or curing the thermally expandable composition described in [1] or [2] above to obtain a roll having a length of 1 m or more.

[11] A method for producing a thermally expandable material-containing component, comprising applying the thermally expandable composition described in [1] or [2] above to a component, and solidifying, drying, or curing the composition to obtain a thermally expandable material-containing component.

[12] A fire protection system having at least a part thereof equipped with the thermally expandable fire-resistant sheet according to any one of [3] to [9] above. Effect of the Invention

[0007] According to the present invention, it is possible to provide a thermally expandable composition and a thermally expandable fire-resistant sheet that can maintain good fire resistance even if warping occurs in a fire prevention facility during a fire. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The present invention will be described in detail below. [Thermal expandable composition] The thermally expandable composition of the present invention contains a matrix component, thermally expandable graphite, and a heat-absorbing agent, and the difference between the expansion onset temperature X of the thermally expandable graphite and the endothermic onset temperature Y of the endothermic agent is within 100° C., and the decomposition temperature Z of the matrix component is equal to or higher than the expansion onset temperature X and the endothermic onset temperature Y.

[0009] <Expansion start temperature, endothermic start temperature> In the thermally expandable composition of the present invention, the difference between the expansion onset temperature X of the thermally expandable graphite and the endothermic onset temperature Y of the endothermic agent is within 100° C. This can be expressed by the following formula (1). |Expansion start temperature X-Endothermic start temperature Y|≦100 Equation (1) In addition, the symbol "||" in equation (1) represents an absolute value.

[0010] When the difference between the expansion onset temperature X and the endothermic onset temperature Y is within 100° C., the thermally expandable fire-resistant sheet formed from the thermally expandable composition can easily conform to deformation due to warping of various fire prevention equipment. When the difference between the expansion start temperature X and the heat absorption start temperature Y is within 100° C., this means that the expansion start temperature X and the heat absorption start temperature Y are relatively close to each other. In this case, the heat generated during a fire is absorbed by the heat-absorbing agent, so that less heat is transferred to the thermally expandable graphite, suppressing expansion. Therefore, the expansion of the thermally expandable graphite does not complete in a short time, but can continue for a long time. This allows the thermally expandable graphite to expand even at high temperatures that would cause the fire protection equipment to warp, improving the ability of the thermally expandable fire-resistant sheet to conform to the fire protection equipment, and maintaining good fire resistance. From the viewpoint of improving fire resistance, the difference between the expansion start temperature X and the endothermic start temperature Y is preferably 90°C or less, and more preferably 60°C or less.

[0011] The expansion start temperature X of the thermally expandable graphite is not particularly limited, but is preferably 100 to 160° C., and more preferably 120 to 150° C. When the expansion start temperature of the thermally expandable graphite is within the above range, it becomes easy to adjust the expansion start temperature of the thermally expandable composition and the thermally expandable fire-resistant sheet to, for example, 160° C. or less, and the thermally expandable composition and the thermally expandable fire-resistant sheet expand in the early stage of a fire to form a fire-resistant heat insulating layer, and it becomes easy to maintain good fire resistance for a long period of time. The endothermic onset temperature Y of the endothermic agent is not particularly limited, but is preferably 150 to 250° C., and more preferably 170 to 230° C. By setting the endothermic onset temperature Y of the endothermic agent in such a range, it becomes easy to adjust the difference between the expansion onset temperature X and the endothermic onset temperature Y to within 100° C.

[0012] It is preferable that the endothermic start temperature Y is higher than the expansion start temperature X. This allows the thermally expandable graphite to expand for a long time, and the thermally expandable fire-resistant sheet can easily follow deformation caused by warping of various fire-prevention equipment. From this viewpoint, it is preferable to satisfy formula (2), and it is more preferable to satisfy formula (3). 10℃≦(endothermic start temperature Y-expansion start temperature X)≦90℃ (2) 30℃≦(endothermic start temperature Y-expansion start temperature X)≦60℃ (3) The expansion start temperature X and the endothermic start temperature Y can be adjusted by the types of thermally expandable graphite and endothermic agent used. The expansion start temperature X and endothermic start temperature Y can be measured by the method described in the Examples.

[0013] <Decomposition start temperature> The decomposition initiation temperature Z of the matrix component is equal to or higher than the expansion initiation temperature X of the thermally expandable graphite. This delays the decomposition of the matrix components during a fire, improves the expansiveness of the thermally expandable fire-resistant sheet, and increases the mechanical strength of the formed fire-resistant heat insulation layer, thereby improving fire resistance. The decomposition initiation temperature Z of the matrix component is preferably 10° C. or more higher than the expansion initiation temperature X of the thermally expandable graphite, more preferably 30° C. or more higher, and even more preferably 50° C. or more higher.

[0014] From the same viewpoint, the decomposition start temperature Z of the matrix component is equal to or higher than the endothermic start temperature Y of the endothermic agent. This delays the decomposition of the matrix component during a fire, improves the expansibility of the thermally expandable fire-resistant sheet, and increases the mechanical strength of the formed fire-resistant insulation layer, thereby improving fire resistance. The decomposition initiation temperature Z of the matrix component is preferably 5° C. or more higher than the endothermic initiation temperature Y of the endothermic agent, more preferably 10° C. or more higher, and even more preferably 30° C. or more higher.

[0015] Here, the decomposition temperature of the matrix component means the decomposition start temperature of the material constituting the matrix component, such as the adhesive described below. When the matrix component is a chemical reaction type adhesive such as a moisture curing reaction type described below, it means the decomposition temperature of the adhesive after curing (i.e., the matrix component after curing). The decomposition start temperature means the temperature at which the matrix component decomposes and starts to lose weight, and is measured using a thermogravimetric measuring device under measurement conditions of a dry air atmosphere, from room temperature (25°C) to 1000°C, and a heating rate of 10°C / min.

[0016] <Matrix components> The thermally expandable composition of the present invention contains a matrix component. In the matrix component, thermally expandable graphite and a heat absorbing agent described below, as well as an inorganic filler other than the heat absorbing agent that is blended as necessary, are dispersed. The matrix component in the thermally conductive composition is preferably an adhesive described below. The matrix component is also a component that becomes the matrix in the thermally expandable fireproof sheet formed from the thermally expandable composition. The matrix component is preferably at least one adhesive selected from the group consisting of a drying-solidifying adhesive, a chemical reaction adhesive, and a hot melt adhesive. The adhesive has high adhesion to thermally expandable graphite and is easily adapted to warping of various fire prevention equipment in the event of a fire. The matrix component may be made of one type of adhesive, or may be made of a combination of multiple adhesives.

[0017] (Dry-curing adhesive) Examples of the dry-solidification type adhesive include a solvent-based adhesive, an emulsion-based adhesive, and a synthetic rubber latex-based adhesive. When using these adhesives, the thermally expandable composition is in a liquid state, which makes it easier to increase the content of thermally expandable graphite, and also makes it easier to cover the thermally expandable graphite with adhesive in the solidified sheet. As a result, the fire-resistant heat-insulating layer, which is the expansion residue of the thermally expandable fire-resistant sheet, is more likely to follow the warping of various fire-prevention equipment.

[0018] The solvent-based adhesive is dissolved in an organic solvent in the thermally expandable composition. Therefore, when the solvent-based adhesive is used, the thermally expandable composition contains an organic solvent. Moreover, the thermally expandable composition can be solidified by volatilizing the organic solvent. Examples of the solvent-based adhesive include vinyl acetate resin-based, vinyl acetate copolymer resin-based, rubber-based, acrylic resin-based, polyester-based, silicone resin-based, etc. The silicone resin-based adhesive is a non-modified silicone resin-based adhesive. In this specification, examples of vinyl acetate copolymer resins include copolymers of vinyl acetate and monomers copolymerizable with vinyl acetate (e.g., α-olefins, (meth)acrylic acid esters, etc.), such as vinyl acetate-(meth)acrylic acid ester copolymers. The (meth)acrylic acid is a concept that includes both acrylic acid and methacrylic acid, and the same applies to other similar terms. In this specification, examples of rubbers include chloroprene, butadiene, styrene-butadiene, butadiene-acrylonitrile, isobutylene-isoprene, ethylene-propylene, etc., of which chloroprene is preferred. Among the solvent-based adhesives, acrylic resin-based or silicone resin-based (non-modified) adhesives are preferred.

[0019] The emulsion type adhesive is dispersed in a dispersion medium, preferably water, in the thermally expandable composition. When an emulsion type adhesive is used, the thermally expandable composition contains a dispersion medium such as water. Examples of emulsion-type adhesives include vinyl acetate resin-based, vinyl acetate copolymer resin-based, acrylic resin-based, aqueous polymer-isocyanate-based, and polyurethane-based adhesives, with vinyl acetate copolymer resin-based and polyurethane-based adhesives being preferred.

[0020] The synthetic rubber latex adhesive is dispersed in a dispersion medium, preferably water, in the thermally expandable composition. When a synthetic rubber latex adhesive is used, the thermally expandable composition contains a dispersion medium such as water. Examples of synthetic rubber latex adhesives include chloroprene, butadiene, styrene-butadiene, butadiene-acrylonitrile, isobutylene-isoprene, and ethylene-propylene, with chloroprene being preferred.

[0021] When a dry-solidifying adhesive is used, the thermally expandable composition contains water or an organic solvent. The solid content of the thermally expandable composition when a dry-solidifying adhesive is used is, for example, 10 to 90% by mass, and preferably 30 to 70% by mass, from the viewpoint of improving the fire resistance of the resulting thermally expandable fire-resistant sheet.

[0022] (Chemical reaction type adhesive) Examples of chemically reactive adhesives include hardener reactive adhesives, moisture curing reactive adhesives, and ultraviolet ray reactive adhesives, with the moisture curing reactive adhesives being preferred.

[0023] <Hardening agent reaction type> The curing agent reaction type adhesive is an adhesive that can be cured by a curing agent, and examples thereof include epoxy resin-based (non-modified), rubber-modified epoxy resin-based, melamine resin-based, urea resin-based, phenolic resin-based, etc. The epoxy resin-based (non-modified) refers to an epoxy resin other than modified epoxy resin, and the rubber-modified epoxy resin-based includes a reaction product of an epoxy resin and rubber, such as an NBR epoxy resin-based resin obtained by reacting an epoxy resin with acrylonitrile butadiene rubber (NBR). As the curing agent, any commonly used curing agent capable of curing the above-mentioned resins can be used without any particular limitation. For example, polyamine-based, imidazole-based, polymercaptan-based, acid anhydride-based, and other curing agents can be used.

[0024] <Moisture curing reaction type> The moisture-curing adhesive is an adhesive that cures with moisture in the air. The thermally expandable composition containing the moisture-curing adhesive can be cured with moisture and kneaded at low temperatures, which makes it particularly easy to reduce the load during kneading and effectively suppresses the deterioration of the thermally expandable graphite. Therefore, the generation of gas caused by the deterioration of the thermally expandable graphite is suppressed, and a long thermally expandable fireproof sheet with an extremely good appearance can be obtained.

[0025] Examples of moisture-curing reactive adhesives include cyanoacrylate-based, modified silicone resin-based, and silylated urethane-based adhesives, with modified silicone resin-based and silylated urethane-based adhesives being preferred, and modified silicone resin-based adhesives being more preferred.

[0026] (Modified silicone resin) An example of a silicone-modified resin-based moisture-curing reaction type adhesive is a polymer having a crosslinkable silyl group (a crosslinkable silyl group-containing polymer). The crosslinkable silyl group-containing polymer is preferably at least one selected from the group consisting of crosslinkable silyl group-containing polyoxyalkylene polymers, crosslinkable silyl group-containing acrylic polymers, and crosslinkable silyl group-containing acrylic-modified polyoxyalkylene polymers. The modified silicone resin-based moisture-curing reaction adhesive is a compound that does not have a urethane bond or a urea bond in the main chain, unlike the silylated urethane-based adhesive described below.

[0027] The crosslinkable silyl group-containing polyoxyalkylene polymer is preferably a polymer containing a crosslinkable silyl group in the molecule and having a polyoxyalkylene in the main chain, more preferably a polymer having a polyoxyalkylene in the main chain and containing a crosslinkable silyl group at the main chain end. The polyoxyalkylene is preferably polyoxypropylene.

[0028] In addition, the crosslinkable silyl group-containing acrylic-modified polyoxyalkylene polymer is preferably a polymer containing a crosslinkable silyl group in the molecule and having a (meth)acrylic-modified polyoxyalkylene in the main chain, and more preferably a polymer having a (meth)acrylic-modified polyoxyalkylene in the main chain and containing a crosslinkable silyl group at the main chain end. In addition, the (meth)acrylic-modified polyoxyalkylene is preferably a (meth)acrylic-modified polyoxypropylene.

[0029] Examples of the crosslinkable silyl group-containing acrylic polymer include polymers having an acrylic polymer in the main chain skeleton and having one or more crosslinkable silyl groups in the molecule. Here, the acrylic polymer may be any conventionally known polymer, and is not particularly limited as long as it is an acrylic polymer obtained by polymerizing or copolymerizing one or more acrylic monomers selected from (meth)acrylic acid, (meth)acrylic acid esters, (meth)acrylonitrile, (meth)acrylamide, and the like.

[0030] Examples of the crosslinkable silyl group include a group in which one or more reactive groups are bonded to a silicon atom.The reactive group is a group selected from a halogen atom, a hydrogen atom, a hydroxyl group, an alkoxy group, an acyloxy group, a ketoximate group, an amide group, an acid amide group, a mercapto group, a ketoxime group, an alkenyloxy group, and an aminooxy group, and when there are a plurality of reactive groups, the reactive groups may be the same or different groups.Among them, the reactive group is preferably an alkoxy group, and more preferably a methoxy group. That is, the crosslinkable silyl group is preferably an alkoxysilyl group.The alkoxysilyl group includes trialkoxysilyl groups such as trimethoxysilyl group, triethoxysilyl group, triisopropoxysilyl group, and triphenoxysilyl group, dialkoxysilyl groups such as dimethoxymethylsilyl group and diethoxymethylsilyl group, and monoalkoxysilyl groups such as methoxydimethylsilyl group and ethoxydimethylsilyl group.Among these, trialkoxysilyl group or dialkoxysilyl group is preferred, and trimethoxysilyl group or dimethoxymethylsilyl group is more preferred.

[0031] (Silylated urethane type) The silylated urethane-based moisture-curing adhesive is a polymer having at least one of a urethane bond and a urea bond in the main chain and a crosslinkable silyl group. The crosslinkable silyl group is preferably at the end of the main chain. The crosslinkable silyl group is the same as that described for the modified silicone resin-based moisture-curing adhesive. The main chain of the silylated urethane-based moisture-curing adhesive preferably has a polyoxyalkylene skeleton and at least one of a urethane bond and a urea bond, and the polyoxyalkylene is preferably polyoxypropylene.

[0032] (curing catalyst) The moisture-curing reactive adhesive is preferably cured by a curing catalyst. Examples of the curing catalyst include dibutyltin dilaurate, dibutyltin oxide, dibutyltin diacetate, dibutyltin phthalate, bis(dibutyltin laurate) oxide, dibutyltin bis(acetylacetonate), dibutyltin bis(monoester maleate), tin octoate, dibutyltin octoate, dioctyltin oxide, dibutyltin bis(triethoxysilicate), bis(dibutyltin bistriethoxysilicate) oxide, dibutyltin oxybisethoxysilicate, and organic tin compounds such as 1,1,3,3-tetrabutyl-1,3-dilauryloxycarbonyl-distannoxane, and organic titanium compounds such as tetra-n-butoxy titanate and tetraisopropoxy titanate. These curing catalysts may be used alone or in combination of two or more. The content of the curing catalyst is preferably from 1 to 10 parts by mass, and more preferably from 1 to 5 parts by mass, based on 100 parts by mass of the matrix component.

[0033] <UV reaction type> The ultraviolet-reactive adhesive is an adhesive that hardens when irradiated with ultraviolet light, and examples thereof include radical polymerization-curing adhesives and cationic polymerization-curing adhesives. Examples of the radical polymerization-curing adhesives include compounds having a polymerizable double bond such as a (meth)acryloyl group and a vinyl group. Examples of the cationic polymerization-curing adhesives include compounds having an epoxy group and compounds having an oxetanyl group. The ultraviolet-reactive adhesives can be used in combination with a polymerization initiator as necessary.

[0034] (Hot melt adhesive) A hot melt adhesive is an adhesive that does not have fluidity at room temperature, but becomes fluid when heated, and is sometimes called a hot melt adhesive. In addition, the heated hot melt adhesive solidifies when cooled again. By using a hot melt adhesive in a thermally expandable composition, even if the fire prevention equipment warps during a fire, the fluidity of the hot melt adhesive increases, making it easier to fill gaps and improve fire resistance. Examples of hot melt adhesives include vinyl acetate resins, vinyl acetate copolymer resins, ethylene-vinyl acetate copolymer resins, rubbers, acrylic resins, polyurethanes, polystyrenes, polyolefins, polyesters, polyamides, etc. The polystyrenes are polymers containing styrene monomers, and may be copolymers of styrene monomers and aliphatic monomers. Among these, any of the ethylene-vinyl acetate copolymer resin, polyurethane, polyester, and polystyrene systems are preferred, and among these, the ethylene-vinyl acetate copolymer resin or polystyrene system is more preferred. When using a hot melt adhesive, a tackifier resin may be used in combination. Examples of tackifier resins include rosin-based, terpene-based, petroleum resin-based, and coumarone resin-based resins.

[0035] The thermally expandable composition of the present invention may be any of a drying-solidifying type adhesive, a chemically reactive type adhesive, and a hot-melt type adhesive. From the viewpoint of improving the ability to conform to warping of fire prevention equipment in the event of a fire, however, a moisture-curing reactive type adhesive is preferred. The type of adhesive is not particularly limited, but is preferably at least one selected from the group consisting of NBR epoxy resin, urea resin, melamine resin, phenolic resin, rubber, vinyl acetate resin, vinyl acetate copolymer resin, ethylene-vinyl acetate copolymer resin, acrylic resin, aqueous polymer-isocyanate, synthetic rubber latex, epoxy resin, cyanoacrylate, polyurethane, acrylic resin, silicone resin (unmodified), modified silicone resin, silylated urethane, polystyrene, and polyester.

[0036] In the present invention, the content of the matrix component is preferably 20 to 80 mass %, more preferably 30 to 70 mass %, based on the total solid content of the thermally expandable composition, from the viewpoint of improving fire resistance.

[0037] <Thermal expandable graphite> The thermally expandable composition of the present invention contains thermally expandable graphite. Note that in this specification, thermally expandable graphite does not fall under the category of inorganic fillers, which will be described later. Thermally expandable graphite is a conventionally known substance that expands when heated. When heated, it expands to form large-capacity voids, which inhibits the spread of fire or extinguishes the fire if the fire-resistant sheet catches fire. Thermally expandable graphite is a type of crystalline compound that is produced by treating powders of natural flaky graphite, pyrolytic graphite, kish graphite, or the like with an inorganic acid and a strong oxidizing agent to generate a graphite intercalation compound, and that maintains the layered structure of carbon. Examples of inorganic acids include concentrated sulfuric acid, nitric acid, and selenic acid. Examples of strong oxidizing agents include concentrated nitric acid, persulfates, perchloric acid, perchlorates, permanganates, dichromates, dichromates, and hydrogen peroxide. The thermally expandable graphite obtained by the acid treatment as described above may be further neutralized with ammonia, aliphatic lower amines, alkali metal compounds, alkaline earth metal compounds, and the like.

[0038] The particle size of the thermally expandable graphite is preferably 20 to 200 mesh. When the particle size of the thermally expandable graphite is within the above range, it expands and easily creates large-volume voids, improving fire resistance. Also, dispersibility in resin is improved. The average aspect ratio of the thermally expandable graphite is preferably 2 or more, more preferably 5 or more, and even more preferably 10 or more. The upper limit of the average aspect ratio of the thermally expandable graphite is not particularly limited, but from the viewpoint of preventing cracking of the thermally expandable graphite, it is preferably 1,000 or less. When the average aspect ratio of the thermally expandable graphite is 2 or more, it is easy to expand and form large-capacity voids, and thus the flame retardancy is improved. The average aspect ratio of the thermally expandable graphite is determined by measuring the maximum dimension (long diameter) and the minimum dimension (short diameter) of each of 10 pieces of thermally expandable graphite, and averaging the values ​​obtained by dividing the maximum dimension (long diameter) by the minimum dimension (short diameter). The major and minor diameters of the thermally expandable graphite can be measured, for example, using a field emission scanning electron microscope (FE-SEM).

[0039] The expansion start temperature of the thermally expandable graphite is not particularly limited, but is preferably 100 to 160° C., and more preferably 120 to 150° C. When the expansion start temperature of the thermally expandable graphite is within the above range, it becomes easy to adjust the expansion start temperature of the thermally expandable composition and the thermally expandable fire-resistant sheet to, for example, 160° C. or less, and the thermally expandable composition and the thermally expandable fire-resistant sheet expand in the early stage of a fire to form a fire-resistant heat insulating layer, and it becomes easy to maintain good fire resistance for a long period of time. The expansion starting temperature of the thermally expandable graphite is measured by the method described in the Examples.

[0040] The content of the thermally expandable graphite is preferably 3 to 300 parts by mass, more preferably 10 to 200 parts by mass, and even more preferably 30 to 100 parts by mass, relative to 100 parts by mass of the matrix component. When the content of the thermally expandable graphite is equal to or greater than these lower limits, the thermally expandable fire-resistant sheet can be given appropriate fire resistance. When the content of the thermally expandable graphite is equal to or less than these upper limits, the matrix component can be contained at a certain level or more, so that the thermally expandable graphite can be easily covered with an adhesive, and the thermally expandable graphite can easily follow the warping of the fire prevention equipment.

[0041] <Heat absorbing agent> The thermally expandable composition of the present invention contains a heat absorbing agent. In this specification, the heat absorbing agent corresponds to an inorganic filler. By using the heat absorbing agent, the expansion of the thermally expandable graphite continues for a long time in the event of a fire, and therefore the thermally expandable graphite can expand even at high temperatures that would cause warping of the fire prevention equipment, improving the fire resistance.

[0042] The type of the heat absorbing agent is not particularly limited, but examples thereof include metal hydroxides, boron compounds, and metal salts. Examples of metal hydroxides include aluminum hydroxide, magnesium hydroxide, calcium hydroxide, and hydrotalcite. The boron-based compound may be zinc borate, which may be a hydrate such as 2ZnO·3B2O5·3.5H2O. Examples of the metal salt include calcium sulfate and magnesium sulfate, and the metal salt may be a hydrate. Among these, as described above, aluminum hydroxide is preferred as the endothermic agent from the viewpoint of keeping the difference between the expansion onset temperature X and the endothermic onset temperature Y within 100° C. and improving fire resistance.

[0043] From the viewpoint of improving fire resistance, the content of the heat absorbing agent in the thermally expandable composition is preferably 10 to 100 parts by mass, and more preferably 15 to 40 parts by mass, based on 100 parts by mass of the matrix component.

[0044] From the viewpoint of continuing the expansion of the thermally expandable graphite for a long time and improving fire resistance, the content of the heat absorbing agent in the inorganic filler is preferably 5% by mass or more, more preferably 20% by mass or more, and more preferably 30% by mass or more, based on the total amount of the inorganic filler. Also, from the viewpoint of improving the strength of the expanded residue by including a certain amount of inorganic filler other than the heat absorbing agent described later, the content of the heat absorbing agent in the inorganic filler is preferably 90% by mass or less, more preferably 70% by mass or less, based on the total amount of the inorganic filler.

[0045] The thermally expandable composition of the present invention may contain an inorganic filler other than the above-mentioned heat absorbing agent. The inorganic filler expands when heated, and when the fireproof heat insulating layer is formed, increases the heat capacity and suppresses heat transfer, while acting as an aggregate to improve the strength of the expansion residue. The inorganic filler that can be used in the present invention 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 calcium carbonate, zinc carbonate, strontium carbonate, and barium carbonate, gypsum fiber, calcium salts such as calcium silicate, silica, diatomaceous earth, dawsonite, 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, various metal powders, metal phosphite, potassium titanate, lead zirconate titanate, aluminum borate, molybdenum sulfide, silicon carbide, stainless steel fiber, and zinc borate. These inorganic fillers other than the heat absorbing agent may be used alone or in combination of two or more. Among these, calcium carbonate is preferred. The inorganic fillers other than the heat absorbing agent may be used alone or in combination of two or more kinds.

[0046] From the viewpoint of improving fire resistance, the content of the inorganic filler is preferably 2 to 200 parts by mass, more preferably 10 to 150 parts by mass, and further preferably 30 to 100 parts by mass, relative to 100 parts by mass of the matrix component.

[0047] <Plasticizer> The thermally expandable composition of the present invention may contain a plasticizer from the viewpoint of improving moldability. Examples of the plasticizer include phthalate ester plasticizers such as di-2-ethylhexyl phthalate (DOP), dibutyl phthalate (DBP), diheptyl phthalate (DHP), and diisodecyl phthalate (DIDP), fatty acid ester plasticizers such as di-2-ethylhexyl adipate (DOA), diisobutyl adipate (DIBA), and dibutyl adipate (DBA), epoxidized ester plasticizers such as epoxidized soybean oil, adipic acid ester plasticizers such as adipic acid ester and adipic acid polyester, trimellitic acid ester plasticizers such as tri-2-ethylhexyl trimellitate (TOTM) and triisononyl trimellitate (TINTM), and process oils such as mineral oil. The plasticizers may be used alone or in combination of two or more. When the thermally expandable composition contains a plasticizer, the content of the plasticizer is preferably from 1 to 60 parts by mass, and more preferably from 5 to 50 parts by mass, per 100 parts by mass of the matrix component.

[0048] (Other ingredients) The thermally expandable composition of the present invention may contain additive components other than those described above as necessary, as long as 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 lubricants, shrinkage inhibitors, crystal nucleating agents, colorants (pigments, dyes, etc.), ultraviolet absorbers, antioxidants, antiaging agents, flame retardants, flame retardant assistants, antistatic agents, surfactants, vulcanizing agents, dispersants, and surface treatment agents. The amount of additives added can be appropriately selected within a range that does not impair moldability, etc., and the additives may be used alone or in combination of two or more.

[0049] The thermally expandable composition of the present invention can be prepared by mixing the matrix component, the thermally expandable graphite, the inorganic filler including the heat absorbing agent, and other additives. The mixing can be performed using a known device such as a Banbury mixer, a kneader mixer, a kneading roll, a Raikai mixer, or a planetary mixer.

[0050] [Thermal expansion fireproof sheet] The heat-expandable fire-resistant sheet of the present invention is made of the heat-expandable composition described above, and can be obtained by molding the heat-expandable composition as described below. Therefore, the heat-expandable fire-resistant sheet contains a matrix component, heat-expandable graphite, and an inorganic filler and other additives that are blended as necessary.

[0051] <Expansion start temperature> The thermally expandable fireproof sheet of the present invention preferably has an expansion start temperature of 160° C. or less. By having an expansion start temperature of 160° C. or less, the sheet expands in the early stage of a fire when the temperature is relatively low to form a fire-resistant heat insulating layer, which makes it easier to maintain good fire resistance for a long period of time. The expansion starting temperature of the thermally expandable fire-resistant sheet is preferably 155°C or lower, more preferably 150°C or lower, and preferably 120°C or higher. The expansion initiation temperature of the thermally expandable fire-resistant sheet is measured by the method described in the Examples.

[0052] <Elution rate> The heat-expandable fireproof sheet of the present invention preferably has an elution rate of 3% or less after immersion in pure water at 60° C. for one week. If the elution rate is 3% or less, even if the heat-expandable fireproof sheet is placed in a high humidity environment or in an environment where it comes into contact with water, the elution of the components constituting the heat-expandable fireproof sheet can be suppressed, and a decrease in fire resistance can be prevented. In addition, when the heat-expandable fireproof sheet is installed in a fireproof facility, contamination of the fireproof facility and the occurrence of poor appearance can be prevented. The elution rate of the thermally expandable fire-resistant sheet is preferably 2% or less, more preferably 1% or less. The lower the elution rate, the better, with the lower limit being 0%. The elution rate can be adjusted by appropriately selecting each component to be blended in the heat-expandable fireproof sheet. Specifically, it is sufficient to use compounds with low solubility in water for the matrix component, heat-expandable graphite, inorganic filler blended as required, and other additives. The dissolution rate is measured by the method described in the Examples.

[0053] <Phosphorus component> The matrix component contained in the heat-expandable fire-resistant sheet of the present invention preferably does not contain a phosphorus component. By using a matrix component that does not contain a phosphorus component, the phosphorus component of the heat-expandable fire-resistant sheet can be reduced. In addition, it is preferable that the components other than the matrix component contained in the heat-expandable fire-resistant sheet do not contain a phosphorus component. In other words, it is preferable that the heat-expandable fire-resistant sheet does not contain a phosphorus component. The matrix component and the thermally expandable fireproof sheet may contain an amount of phosphorus component that is inevitably contained as an impurity. That is, in this specification, "not containing phosphorus component" means that the content of phosphorus component is 0.1 mass % or less, preferably 0.01 mass % or less. By not containing a phosphorus component, water resistance is improved, and therefore it becomes possible to ensure excellent expansion ratio, residual hardness, and shape retention after expansion even after long-term exposure to water. Here, the phosphorus component is a compound containing a phosphorus atom, and it is preferable not to use a compound containing a phosphorus atom as the above-mentioned matrix component, thermally expandable graphite, and inorganic filler that is mixed as necessary, or other additives.

[0054] <Long products> The heat-expandable fireproof sheet of the present invention is also preferably 1 m or more in length. The length is the length in the longitudinal direction (MD direction) of the heat-expandable fireproof sheet. By making the length 1 m or more, the productivity is improved and the range of applications is expanded, which is preferable. The length of the heat-expandable fireproof sheet is preferably 5 m or more, more preferably 20 m or more, even more preferably 50 m or more, and even more preferably 100 m or more. In addition, the length of the heat-expandable fireproof sheet is usually 500 m or less. In this specification, the MD direction is an abbreviation for Machine Direction, and is the same as the flow direction of the composition during coating, etc., which will be described later, and is the longitudinal direction of the sheet, while the TD direction is an abbreviation for Transverse Direction, and is the direction perpendicular to the MD direction.

[0055] Furthermore, the thermally expandable fire-resistant sheet of the present invention can reduce thickness variation even when the sheet is made to be 1 m or longer in length, and can provide a long product with high dimensional accuracy. In the present invention, since a specific matrix component is used, the kneading load is small when kneading the composition, and therefore deterioration of the thermally expandable graphite can be suppressed, and it is presumed that this can suppress gas generation and reduce unevenness in thickness. In particular, when a liquid thermally expandable composition or a moisture-curing reactive type is used as the matrix component, deterioration of the thermally expandable graphite can be easily suppressed.

[0056] Specifically, because the thermally expandable fire-resistant sheet of the present invention has a specific composition, even when the sheet is 1 m or longer in length, it can have a thickness of 0.5 mm or more and a thickness variation of 0.1 mm or less. Here, the "thickness" of 0.5 mm or more means the average thickness, and the average thickness means the average value when the thickness is measured at 10 points at equal intervals in the longitudinal direction of the thermally expandable fireproof sheet. The thickness (average thickness) is preferably 0.8 mm or more, more preferably 1 mm or more, and preferably 5 mm or less. The thickness is measured at the center of the sheet in the width direction. The thickness variation, as described above, is determined by measuring the thickness at 10 points at equal intervals in the longitudinal direction of the thermally expandable fireproof sheet, calculating the absolute value A of the difference between the thickness measured at each point and the average thickness, and averaging the absolute values ​​A for the 10 points. The thickness variation is preferably 0.1 mm or less, more preferably 0.08 mm or less, and even more preferably 0.05 mm or less. Furthermore, the variation in thickness is preferably 10% or less of the thickness (average thickness), and more preferably 5% or less.

[0057] The heat-expandable fireproof sheet of the present invention preferably has a heat shrinkage rate of 1% or less, more preferably 0.5% or less, in both the MD and TD directions, even when the sheet has a length of 1 m or more. If the heat shrinkage rate is low, peeling due to shrinkage or dimensional insufficiency can be suppressed, even if heat is applied during the manufacturing process of the roll. The heat shrinkage rate is calculated from the length before and after heat treatment by cutting out a 100 mm square evaluation sample and heat treating it at 60°C for 6 hours, based on the following formula: Heat shrinkage rate (%) = 100 x (length before heat treatment - length after heat treatment) / length before heat treatment The heat shrinkage rate in the MD direction and the heat shrinkage rate in the TD direction can be calculated based on the above formula from the length in the MD direction and the length in the TD direction before heat treatment and the length after heat treatment. In addition, 10 or more evaluation samples of 100 mm square are prepared at equal intervals in the longitudinal direction of the sheet, and the heat shrinkage ratios calculated from the individual evaluation samples are averaged to determine the heat shrinkage ratio in the MD direction and the heat shrinkage ratio in the TD direction. The thermal shrinkage rate can be adjusted by adjusting the contents of the various components constituting the thermally expandable fire-resistant sheet.

[0058] The thermally expandable fireproof sheet of the present invention can be wound into a roll having a length of 1 m or more. In particular, in the case of a thermally expandable fireproof sheet having a small thickness variation and high dimensional accuracy, it becomes easy to efficiently manufacture a roll of a long sheet. The rolled body in the present invention is a heat-expandable fireproof sheet having a length of 1 m or more wound into a roll, for example, a heat-expandable fireproof sheet having a length of 1 m or more wound around a cylindrical core. The core may not be required. The width of the thermally expandable fireproof sheet is not particularly limited, but is, for example, 0.005 to 2.0 m. As described later, the heat-expandable fire-resistant sheet (multilayer sheet) having a base material or an adhesive layer may be wound into a roll.

[0059] <Manufacturing method of thermally expandable fireproof sheet> The method for producing the thermally expandable fireproof sheet of the present invention is not particularly limited, but a method of solidifying, drying, or curing the thermally expandable composition described above is preferable. By such a production method, for example, the above-mentioned rolled body having a length of 1 m or more can be obtained. Specifically, the thermally expandable composition may be applied to an arbitrary object, and the applied thermally expandable composition may be solidified, dried, or cured. The thermally expandable composition may be applied using a known coating device, spray, or the like.

[0060] For example, when the above-mentioned drying and solidifying type adhesive is used as the matrix component, since the thermally expandable composition is in a liquid state containing a solvent, the thermally expandable fireproof sheet can be formed by drying the thermally expandable composition after application to remove the solvent. Drying may be performed by leaving it at around room temperature (about 25°C), but is preferably performed by heating. Heating is preferably performed at a temperature below the expansion start temperature of the thermally expandable graphite, for example, at about 50 to 160°C, preferably about 60 to 120°C.

[0061] When the above-mentioned chemically reactive adhesive is used as the matrix component, the thermally expandable fireproof sheet can be obtained by curing the thermally expandable composition after application. The curing method may be appropriately selected depending on the type of matrix component. When a curing agent-reactive adhesive is used, the curing can be promoted by mixing with a curing agent. That is, after adding a curing agent to the thermally expandable composition, the thermally expandable composition may be applied to an arbitrary object and cured, or the thermally expandable composition may be a two-liquid type consisting of a liquid containing a curing agent and a liquid not containing a curing agent, and the two liquids of the two-liquid type thermally expandable composition may be mixed and applied to an arbitrary object and cured. In the case of a moisture-curing adhesive, it is sufficient to apply it to an object and then leave it in the air for a predetermined period of time, allowing the moisture in the air to promote curing. In the case of an ultraviolet-reactive adhesive, after it is applied to an object, curing can be promoted by irradiating it with ultraviolet light.

[0062] When a hot melt adhesive is used as the matrix component, the thermally expandable composition is melted by heating, and the melted thermally expandable composition is applied to any object. The heating temperature during melting is preferably below the expansion start temperature of the thermally expandable graphite, for example, 80 to 160°C, and preferably about 100 to 120°C. After the thermally expandable composition is applied, it is cooled to room temperature (25°C) for solidification, and a thermally expandable fireproof sheet can be obtained.

[0063] The object to which the thermally expandable composition is applied is not particularly limited, but may be, for example, a release-treated resin film, or when producing a thermally expandable fire-resistant sheet having a substrate, the substrate may be the object to which the thermally expandable composition is applied.

[0064] <Substrate, adhesive layer, separator> The heat-expandable fireproof sheet of the present invention may be used alone, or may be used as a multilayer sheet by appropriately attaching other members. Specifically, the heat-expandable fireproof sheet may have a substrate or an adhesive layer on at least one surface. For example, the heat-expandable fireproof sheet may have a substrate on one surface (substrate / heat-expandable fireproof sheet multilayer sheet), may have an adhesive layer on one surface (adhesive layer / heat-expandable fireproof sheet multilayer sheet), or may have a substrate on one surface and an adhesive layer on the other surface (adhesive layer / heat-expandable fireproof sheet / substrate multilayer sheet). Furthermore, the heat-expandable fireproof sheet may have a separator, for example, a separator may be provided on the surface of the adhesive layer.

[0065] (base material) The substrate may be in the form of, for example, a woven fabric, a nonwoven fabric, a film, or the like, and may be made of a thermoplastic resin, a thermosetting resin, an elastomeric resin, or the like, and is preferably made of a thermoplastic resin among these. The substrate may also be made of glass fiber, ceramic fiber, cellulose fiber, polyester fiber, carbon fiber, graphite fiber, thermosetting resin fiber, or the like. The preferred form of the substrate is a film. A film having a cavity therein can also be suitably used as the film.

[0066] Specific examples of thermoplastic resins include polyesters such as polyvinyl chloride, polyethylene terephthalate, and polybutylene terephthalate; polyolefins such as polyethylene, polypropylene, poly(1-butene), and polypentene; polyvinyl acetate, polystyrene, acrylic resins, acrylonitrile-butadiene-styrene (ABS) resins, polycarbonates, polyamides, polyphenylene ethers, and polyethersulfones. Among the above, from the viewpoint of adhesion to the thermally expandable fireproof sheet, preferred thermoplastic resins are polyvinyl chloride, polyethylene terephthalate, polyolefin, and polyvinyl acetate. Furthermore, from the viewpoint of flame retardancy, polyvinyl chloride is more preferred. Also preferred is a polyethylene terephthalate film having a cavity inside.

[0067] Specific examples of the thermosetting resin include epoxy resin, urethane resin, phenol resin, unsaturated polyester, alkyd resin, urea resin, and polyimide.

[0068] Specific examples of elastomer resins include isoprene rubber, butadiene rubber, 1,2-polybutadiene rubber, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, butyl rubber, ethylene-propylene rubber, chlorosulfonated polyethylene, acrylic rubber, epichlorohydrin rubber, silicone rubber, fluororubber, urethane rubber, polyisobutylene rubber, and chlorinated butyl rubber. One or more of the above thermoplastic resins, thermosetting resins and elastomer resins are used.

[0069] The thickness of the substrate is preferably 1 to 20% of the thickness of the multilayer sheet. When the thickness of the substrate is 1% or more of the thickness of the multilayer sheet, the substrate easily supports the heat-expandable fire-resistant sheet. When the thickness of the substrate is 20% or less of the thickness of the multilayer sheet, peeling between the substrate and the heat-expandable fire-resistant sheet and wrinkles on the substrate are suppressed when the multilayer sheet is curved, and the appearance of the multilayer sheet can be maintained in a good condition.

[0070] The thickness of the substrate is, for example, 10 to 500 μm, preferably 20 to 450 μm, and more preferably 30 to 400 μm. By making the thickness of the substrate equal to or greater than these lower limits, the substrate can be provided with the strength to support the thermally expandable fireproof sheet. By making the thickness equal to or less than the upper limits, the thickness of the substrate can be prevented from becoming thicker than necessary, and the multilayer sheet can be easily used in fire prevention equipment such as doors.

[0071] (Adhesive layer) The adhesive layer may be a single layer (hereinafter also referred to as adhesive layer) formed only from an adhesive, or may be a double-sided adhesive tape in which adhesive layers are provided on both surfaces of a substrate for a double-sided adhesive tape, but is preferably made of an adhesive layer. Note that the adhesive layer of the double-sided adhesive tape is formed by bonding one of the adhesive layers to a heat-expandable fire-resistant sheet or a separator. The adhesive constituting the adhesive layer is not particularly limited, and examples thereof include acrylic adhesives, urethane adhesives, rubber adhesives, etc. The thickness of the adhesive layer is not particularly limited, and is, for example, 10 to 500 μm, and preferably 50 to 200 μm. The substrate for the double-sided pressure-sensitive adhesive tape is not particularly limited as long as it is a substrate used in general double-sided pressure-sensitive adhesive tapes, and examples thereof include nonwoven fabrics, paper such as Japanese paper, woven fabrics made of natural fibers, synthetic fibers, etc., resin films made of polyester, polyolefin, soft polyvinyl chloride, hard polyvinyl chloride, acetate, etc., and flat yarn cloth.

[0072] (Separator) The separator may be, for example, one that includes a separator substrate and a release layer provided on at least one surface of the separator substrate. The release layer can be formed by subjecting the separator substrate to a release treatment. The separator may be disposed so that the surface on which the release layer is provided is in contact with the adhesive layer. Alternatively, the separator may be such that both surfaces of the separator substrate are subjected to a release treatment, and release layers are provided on both surfaces. The release layer is not particularly limited, but may be made of, for example, an organic resin. As the organic resin, any known release agent may be used, such as a fluorine-based resin, a long-chain alkyl-containing resin, an alkyd-based resin, a polyolefin-based resin, or a rubber-based elastomer. The separator substrate may be a resin film, paper, or the like. The resin film may be formed from a thermoplastic resin, a thermosetting resin, an elastomer resin, or the like. Specific examples of the thermoplastic resin, the thermosetting resin, or the elastomer resin may include those listed in the resin film, but a thermoplastic resin is preferred.

[0073] The thickness of the separator is preferably 0.3 to 10% of the thickness of the multilayer sheet. When the thickness of the separator is 0.3% or more of the thickness of the multilayer sheet, the separator is more likely to be prevented from being broken. When the thickness of the separator is 10% or less of the thickness of the multilayer sheet, peeling between the heat-expandable fireproof sheet and the separator and the occurrence of wrinkles in the separator are prevented when the multilayer sheet is curved, and the appearance of the multilayer sheet can be maintained in a good condition.

[0074] The thickness of the separator is, for example, 1 to 200 μm, preferably 2 to 150 μm, and more preferably 5 to 100 μm. By making the thickness of the separator equal to or greater than these lower limits, the separator can be provided with sufficient strength to withstand breakage. By making the thickness equal to or less than the upper limits, peeling between the fireproof material and the separator and wrinkles on the separator can be prevented when the multilayer sheet is curved.

[0075] <Method for manufacturing thermally expandable material-containing member> The present invention also provides a method for producing a thermally expandable material-containing member, which comprises applying the above-mentioned thermally expandable composition to a member and solidifying, drying, or curing the composition to obtain a thermally expandable material-containing member. The above-mentioned member is an object to which the thermally expandable composition is used, and is preferably, for example, a fire prevention facility described below. Examples of the fire prevention facility include fittings such as windows, shoji screens, doors, doors, and sliding doors, pillars, walls such as steel-framed concrete, floors, roofs, and the like. The thermally expandable material is formed by solidifying, drying, or curing the thermally expandable composition. The solidifying, drying, or curing is as described in the manufacturing method of the thermally expandable fire-resistant sheet. The expansion start temperature, elution rate, and amount of phosphorus component of the thermally expandable material are in the same range as those of the thermally expandable fire-resistant sheet described above. The thermally expandable material-containing member of the present invention can maintain good fire resistance even if warping occurs during a fire.

[0076] [Fire prevention equipment] In the present invention, it is possible to provide a fire prevention facility at least partially equipped with the above-mentioned heat-expandable fireproof sheet. Examples of fire prevention facilities include fittings such as windows, shoji screens, doors, doors, and sliding doors, pillars, walls such as steel-framed concrete, floors, and roofs. The heat-expandable fireproof sheet of the present invention is mounted on a part of these fire prevention facilities and expands during a fire, thereby reducing or preventing the intrusion of flames and smoke. In particular, the heat-expandable fireproof sheet is preferably used in the gap between a window and a window frame, the gap between a door and a door frame, etc., and even if these various fire prevention facilities are warped and deformed during a fire, the heat-expandable fireproof sheet of the present invention is easy to follow the warp, and can prevent the intrusion of flames and smoke continuously for a long time, thereby maintaining good fire resistance for a long time. EXAMPLES

[0077] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these.

[0078] The methods for measuring and evaluating each physical property are as follows. <Expansion start temperature of thermally expandable graphite> In a rheometer ("Discovery HR-2", manufactured by TA Instruments), 0.5 g of a sample of thermally expandable graphite was placed on the sample stage and wrapped in aluminum foil to prevent the powder from falling off. The sample was grounded with a 25 mm diameter cone plate until the load reached 0 [N]. From that state, the sample was heated at a constant heating rate (10 °C / min) from the set temperature of 50 °C using a Peltier heater, and the point at which the load reached 0.1 N was taken as the expansion start temperature.

[0079] <Expansion start temperature of thermally expandable fireproof sheet> A thermally expandable fireproof sheet was used as a sample, and a rheometer ("Discovery HR2" manufactured by TA Instruments) was used to raise the temperature at a rate of 10°C / min. The temperature at which the normal force rose was measured and this was taken as the expansion starting temperature.

[0080] <Endothermic start temperature of endothermic agent> The measurements were performed using a thermogravimetric differential thermal analyzer (TG-DTA). The measurement conditions were room temperature to 10 The temperature was increased to 00°C at a rate of 4°C / min, and the weight of the endothermic agent was 10 mg. The temperature at which the weight began to decrease was taken as the endothermic onset temperature.

[0081] <Decomposition temperature of matrix components> The decomposition starting temperature of the matrix component was measured by the method described in the specification. In addition, when the matrix component is a moisture-curing reaction type, the decomposition start temperature of the cured matrix component was measured and used as the decomposition start temperature of the matrix component. The curing conditions were a temperature of 50°C and a relative humidity (RH) of 80% for 6 hours.

[0082] <Heat shrinkage rate> The thermal shrinkage of the matrix component was measured by the method described in the specification.

[0083] <Thickness variation> The thickness of the thermally expandable fire-resistant sheet was measured at 10 points at equal intervals in the longitudinal direction, and the thicknesses at these 10 points were averaged to obtain the average thickness. Next, the thickness was measured at 10 equally spaced points along the longitudinal direction of the heat-expandable fire-resistant sheet, and the absolute value A of the difference between the thickness measured at each point and the above average thickness was calculated. The average of the absolute values ​​A of the 10 points was taken as the thickness variation. If the thickness variation was 10% or less of the thickness (average thickness), it was evaluated as "good", and if it exceeded 10%, it was evaluated as "poor".

[0084] <Elution rate> The obtained thermally expandable fireproof sheet was cut out to prepare a test piece (10 g), which was then immersed in 200 g of pure water and left in a sealed container at 60°C for one week. The test piece was then removed, the pure water was evaporated and dried, and the mass of the precipitate was measured. The elution rate was calculated using the following formula and used as an index of water resistance. Dissolution rate (%) = [(mass of precipitate) / (mass of test piece before immersion in pure water)] × 100

[0085] <Fire resistance> The obtained thermally expandable fireproof sheet was evaluated for fire resistance in accordance with ISO 12472: 2003. Specifically, a test specimen was prepared based on the diagram in ISO 12472: 2003, heated according to the heating curve of ISO 834, and 15 minutes after the start of heating, a load of 7.5 kg was applied to force deformation, and the test specimen was observed after heating for a total of 60 minutes. The evaluation was based on the following criteria. 〇: No penetration into the furnace ×: Penetration into the furnace

[0086] The components used in the examples and comparative examples are as follows. <Matrix components> Acrylic resin type: DIC "ACRYDIC 57-773-BA", dry-hardening adhesive (solvent-based adhesive), solvent (ethyl acetate, butyl acetate) Silicone resin type (non-modified): Shin-Etsu Silicone "KR220L", dry-hardening adhesive (solvent-based adhesive), solvent (toluene, isopropyl alcohol) Ethylene-vinyl acetate copolymer resin (EVA type), Mitsui Chemicals' "V5774ETWR", hot melt adhesive Polystyrene-based, Mitsui Chemicals' "FTR6100", hot melt adhesive Modified silicone resin: Polymer with crosslinkable silyl groups, Kaneka's MS Polymer S-303, moisture curing reaction type Modified silicone resin: Polymer with crosslinkable silyl groups, Toagosei's "US-6150", moisture curing reaction type Modified silicone resin: Polymer with crosslinkable silyl groups, AGC's "Exestar-S6250", moisture curing reaction type Modified silicone resin: Polymer with crosslinkable silyl groups, Soken Chemical Industries, Ltd. "SE-09", moisture curing reaction type Modified silicone resin: Polymer with crosslinkable silyl groups, Kaneka's "Silyl EST280", moisture curing reaction type ·Silylated urethane type: "SPUR3030" manufactured by Momentive Performance Materials Japan

[0087] <Curing catalyst> - "Neostan U220H" manufactured by Nitto Kasei

[0088] <Thermal expandable graphite> Fuji Graphite Industries "EXP-50S150", expansion start temperature 150℃

[0089] <Inorganic fillers> Aluminum hydroxide (Shiraishi Calcium Co., Ltd.) Calcium carbonate (Shiraishi Calcium Co., Ltd.) Calcium hydroxide (manufactured by Adachi Lime Industry Co., Ltd.)

[0090] [Examples 1-2] The components were mixed with a stirrer to obtain a thermally expandable composition as shown in Table 1. The thermally expandable composition was then applied to a release PET film with a roll coater, and the applied product was dried at 120°C to evaporate the solvent, forming a thermally expandable fireproof sheet on the release PET film. The thermally expandable fireproof sheet (length 100 mm, thickness 1.5 mm, width 10 mm) was subjected to various evaluations.

[0091] [Examples 3 to 4] The components were mixed with a stirrer to obtain a thermally expandable composition as shown in Table 1. The thermally expandable composition was then heated to 120°C to melt, and then coated on a release PET film with a roll coater. The coated product was cooled to room temperature (25°C) to solidify, forming a thermally expandable fireproof sheet on the release PET film. Various evaluations were performed on the thermally expandable fireproof sheet (length 100 mm, thickness 1.5 mm, width 10 mm). The results of the evaluations are shown in Table 1.

[0092] [Examples 5 to 10, Comparative Examples 1 to 2] A thermally expandable composition was obtained by mixing the components at 25°C using a stirrer to obtain the composition shown in Table 1. The thermally expandable composition was then applied onto a release PET film using a roll coater, and the applied product was cured at 50°C to form a thermally expandable fire-resistant sheet on the release PET film. Various evaluations were performed on the thermally expandable fire-resistant sheet (length 20 mm, thickness 1.5 mm, width 10 mm).

[0093] [Table 1] The thermally expandable composition used in the examples also contains a solvent when a dry-solidifying adhesive is used, but Table 1 lists the amount of the solid content of the thermally expandable composition only.

[0094] The thermally expandable composition of each Example is formed from a thermally expandable composition containing a matrix component, thermally expandable graphite, and a heat absorbing agent. The difference between the expansion start temperature X of the thermally expandable graphite and the endothermic start temperature Y of the endothermic agent is within 100° C., and the decomposition start temperature Z of the matrix component is equal to or higher than the expansion start temperature X and the endothermic start temperature Y. It was found that a thermally expandable fireproof sheet formed from a thermally expandable composition that satisfies the requirements of the present invention is easily adapted to warping of fire prevention equipment during a fire and can maintain good fire resistance for a long time. In contrast, the heat-expandable fire-resistant sheet of Comparative Example 1, which does not use a heat-absorbing agent, and the heat-expandable fire-resistant sheet of Comparative Example 2, in which the difference between the expansion start temperature X of the expandable graphite and the heat absorption start temperature Y of the heat-absorbing agent exceeds 100°C, were found to have poor fire resistance.

Claims

1. A thermally expandable composition comprising a matrix component, thermally expandable graphite, and a heat absorbing agent, The difference between the expansion start temperature X of the thermally expandable graphite and the endothermic start temperature Y of the endothermic agent is within 100° C.; A thermally expandable composition, wherein the decomposition initiation temperature Z of the matrix component is equal to or higher than the expansion initiation temperature X and the endothermic initiation temperature Y.

2. 2. The thermally expandable composition according to claim 1, comprising 3 to 300 parts by mass of thermally expandable graphite and 2 to 200 parts by mass of an inorganic filler relative to 100 parts by mass of a matrix component, and a content of the heat absorbing agent in the inorganic filler is 5% by mass or more.

3. A thermally expandable fire-resistant sheet obtained by molding the thermally expandable composition according to claim 1 or 2.

4. The thermally expandable fire-resistant sheet according to claim 3, having an expansion initiation temperature of 160°C or less.

5. The thermally expandable fireproof sheet according to claim 3, which has a dissolution rate of 3% or less after immersion in pure water at 60°C for one week.

6. The thermally expandable fire-resistant sheet according to claim 3, wherein the matrix component does not contain a phosphorus component.

7. The thermally expandable fire-resistant sheet according to claim 3 , which has a substrate or an adhesive layer on at least one surface.

8. The heat-expandable fire-resistant sheet according to claim 3, which is a rolled body having a length of 1 m or more.

9. The heat-expandable fireproof sheet according to claim 3, which has a length of 1 m or more, a thermal shrinkage rate of 1% or less in both the MD and TD directions, a thickness of 0.5 mm or more, and a thickness variation of 0.1 mm or less.

10. A method for producing a thermally expandable fire-resistant sheet, comprising solidifying, drying, or curing the thermally expandable composition according to claim 1 or 2 to obtain a roll having a length of 1 m or more.

11. A method for producing a thermally expandable material-containing member, comprising applying the thermally expandable composition according to claim 1 or 2 to a member, and solidifying, drying, or curing the composition to obtain a thermally expandable material-containing member.

12. A fire protection facility having at least a portion mounted with the thermally expandable fireproof sheet according to claim 3.

Images