Thermally expandable fireproof material

Abstract

The invention addresses the problem of providing a thermally expandable fireproof material that has favorable expansion properties and has a residue that has excellent adhesiveness, making it possible to close off a gap in the event of a fire.　This thermally expandable fireproof material is provided with an expansion layer containing a binder resin and thermally expandable graphite. In a shear load measurement test measuring, under tensile conditions of 3 mm / min, a shear load measurement sample obtained by affixing 25 mm × 25 mm of the thermally expandable fireproof material to the surface of one SUS plate of two SUS plates that have a 50 mm × 50 mm surface area facing opposite one another at an interval that is three times the thickness of the expansion layer of the thermally expandable fireproof material and thereafter heating the foregoing at 500°C for 15 min, a residue of the expansion layer undergoes cohesive failure, and the maximum shear load at that time is 10 N or more.

Description

thermally expandable fireproofing material

[0001] The present invention relates to a thermally expandable fire-resistant material.

[0002] In the construction industry, fireproof materials are used in building materials such as fittings, pillars, and wall materials for fire prevention. Various types of fireproof materials have been developed. For example, Patent Document 1 discloses an invention related to a thermally expandable fireproof material containing an elastomer consisting of rubber and a styrene-based thermoplastic elastomer, thermally expandable graphite, and an inorganic phosphate-based compound. Such a thermally expandable fireproof material expands upon heating, and the combustion residue forms a fireproof insulating layer, thereby exhibiting fireproof insulating performance. A thermally expandable fireproof material containing thermally expandable graphite is installed, for example, in the gap between fittings such as doors and windows installed in openings in buildings and the surrounding frames such as door frames and window frames. In the event of a fire, the sheet expands in the thickness direction to close the gap between the fittings and the frame material and prevent the fire from spreading.

[0003] Patent No. 7142139

[0004] However, even if a thermally expandable fire-resistant material containing thermally expandable graphite has good expansion properties that enable it to close gaps in the event of a fire, if the adhesiveness of the residue of the thermally expandable fire-resistant material is low, it may peel off from building materials such as door frames, creating gaps and reducing fire resistance.

[0005] Therefore, an object of the present invention is to provide a thermally expandable fire-resistant material that has good expansion characteristics that enable gaps to be blocked in the event of a fire, and whose residue has excellent adhesive properties.

[0006] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by a thermally expandable fire-resistant material having an expansion layer containing a binder resin and thermally expandable graphite, in which the failure mode of the expansion residue observed under specific conditions is specific and the maximum shear load measured under specific conditions is equal to or greater than a certain level, and have completed the present invention.

[0007] That is, the present invention provides the following [1] to

[10] . [1] A thermally expandable fireresistant material having an expansion layer containing a binder resin and thermally expandable graphite, wherein the thermally expandable fireresistant material having dimensions of 25 mm x 25 mm is attached to the surface of one of two SUS plates, each having an area of ​​50 mm x 50 mm, facing each other at a distance three times the thickness of the expansion layer of the thermally expandable fireresistant material, and then heated at 500°C for 15 minutes to obtain a shear load measurement sample, which is measured under tensile conditions of 3 mm / min. In a shear load measurement test, the residue of the expansion layer undergoes cohesive failure and the maximum shear load at this time is 10 N or more. [2] The thermally expandable fireresistant material according to [1], wherein when the thermally expandable fireresistant material having dimensions of 25 mm x 25 mm is placed on the surface of a SUS plate and heated at 600°C for 10 minutes, the expansion ratio of the thermally expandable fireresistant material is 25 times or more. [3] The heat-expandable fire-resistant material according to [1] or [2], wherein when the heat-expandable fire-resistant material having dimensions of 25 mm x 25 mm is placed on the surface of a SUS plate and heated at 600°C for 10 minutes, the aspect ratio (VW / HW) of the heat-expandable fire-resistant material's expansion width in the vertical direction (VW) of the SUS plate to the heat-expandable fire-resistant material's expansion width in the horizontal direction (HW) of the SUS plate is 1.3 or less. [4] The thermally expandable fireproof material according to any one of [1] to [3], wherein the thermally expandable fireproof material having dimensions of 25 mm x 25 mm is attached to the surface of one of two facing SUS plates at a distance three times the thickness of the expansion layer of the thermally expandable fireproof material, and the heat treatment is performed at 300°C for 10 minutes, so that the area of ​​the thermally expandable fireproof material as viewed vertically from the SUS plate is at least 3.0 times the area of ​​the thermally expandable fireproof material before heating. [5] The thermally expandable fireproof material according to any one of [1] to [4], wherein the temperature difference T = X - Y between the thermal decomposition temperature X of the binder resin and the expansion onset temperature Y of the thermally expandable graphite is at least 100°C. [6] The thermally expandable fireproof material according to any one of [1] to [5], wherein the binder resin is a thermosetting resin. [7] The thermally expandable fireproof material according to [6], wherein the thermosetting resin includes an epoxy resin. [8] The thermally expandable fire-resistant material according to [6] or [7], wherein the expandable layer further contains a curing accelerator. [9] The thermally expandable fire-resistant material according to any one of [1] to [8], wherein the binder resin does not contain a halogen in its molecular structure.

[10] The thermally expandable fire-resistant material according to any one of [1] to [9], wherein the thermally expandable fire-resistant material is a wound body having a length of 10 m or more.

[0008] According to the present invention, it is possible to provide a thermally expandable fire-resistant material that has good expansion characteristics that enable it to close gaps in the event of a fire, and whose residue has excellent adhesive properties.

[0009] Fig. 1 is a diagram (part 1) for observing the failure mode of the residue of the thermally expandable fire-resistant material and measuring the maximum shear load at that time. Fig. 2 is a diagram (part 2) for observing the failure mode of the residue of the thermally expandable fire-resistant material and measuring the maximum shear load at that time. Fig. 3 is a schematic diagram for conducting a fire resistance test of the thermally expandable fire-resistant material.

[0010] [Thermal-expandable fireproof material] The thermal-expandable fireproof material of the present invention is a thermal-expandable fireproof material having an expansion layer containing a binder resin and thermal-expandable graphite. The thermal-expandable fireproof material may be in the form of a sheet. The thermal-expandable fireproof material may be composed of only the expansion layer, or, as described below, may have other layers such as a substrate (surface layer material) and an adhesive layer in addition to the expansion layer.

[0011] (Failure Mode) In the thermally expandable fireproof material of the present invention, the failure mode of the residue of the expansion layer in a shear load measurement test is cohesive failure. Since the failure mode of the residue of the expansion layer is cohesive failure, the residue of the expansion layer that has expanded due to heating in a fire or the like has excellent adhesion to the installation location of a door frame or other fixture, and can be prevented from peeling off from the fixture, creating voids and reducing fire resistance. In addition to cohesive failure, the failure mode of the residue of the expansion layer in a shear load measurement test can also be interfacial failure. In the case of interfacial failure, the adhesiveness of the expanded residue of the expansion layer is insufficient, causing it to peel off from the fixture, creating voids and reducing fire resistance. The shear load measurement test was carried out by cutting the heat-expandable fire-resistant material to a size of 25 mm x 25 mm, attaching it to the surface of one of two SUS plates, each having an area of ​​50 mm x 50 mm, facing each other at a distance three times the thickness of the expansion layer of the heat-expandable fire-resistant material, and then heating it at 500°C for 15 minutes to obtain a shear load measurement sample, which was then measured under a tensile condition of 3 mm / min.

[0012] (Maximum Shear Load) In the shear load measurement test, the thermally expandable fireproof material of the present invention has a maximum shear load of 10 N or more when the expansion layer undergoes cohesive failure. If the maximum shear load is less than 10 N, the residue of the thermally expandable fireproof material expanded during a fire will not have sufficient adhesiveness and may peel off from the building materials, causing voids and reducing fire resistance. From the viewpoint of improving fire resistance, the maximum shear load of the thermally expandable fireproof material is preferably 15 N or more, more preferably 20 N or more, and even more preferably 30 N or more. The upper limit of the maximum shear load of the thermally expandable fireproof material is not particularly limited, but is, for example, 200 N. The maximum shear load can be adjusted to a desired value by adjusting the type and amount of the binder resin, thermally expandable graphite, and the catalyst, tackifier, and plasticizer that are optionally blended in the thermally expandable fireproof material.

[0013] The method for measuring the maximum shear load of a thermally expandable fireproof material in a shear load measurement sample of the present invention will be described in detail below with reference to FIGS. 1 and 2 . First, a thermally expandable fireproof material is cut to a size (width x length) of 25 mm x 25 mm to prepare a thermally expandable fireproof material 13 as a sample for measuring the maximum shear load. Next, two SUS (stainless steel) plates 11 and 12 are prepared. The two SUS plates 11 and 12 are arranged facing each other at a distance three times the thickness of the expansion layer of the thermally expandable fireproof material. Specifically, the two SUS plates 11 and 12 are arranged facing each other at a distance of 6 mm, which is three times the thickness t of the expansion layer of the thermally expandable fireproof material 13 (2 mm). That is, the distance L between the SUS plates 11 and 12 in FIG. 1 is three times the thickness t of the expansion layer of the thermally expandable fireproof material 13. The SUS plates 11 and 12 are arranged so that the area S where they face each other (i.e., the area where the SUS plates overlap when viewed from the thickness direction) is 50 mm x 50 mm. Although not shown, the SUS plates 11 and 12 are sandwiched and fixed in the thickness direction by fixing members, with spacers placed between them to maintain the gap L. A thermally expandable fire-resistant material 13 cut to the dimensions (width x length) of 25 mm x 25 mm described above is attached to the center of the surface of the SUS plate 11 facing the SUS plate 12. The thermally expandable fire-resistant material 13 is attached to the center of the surface of the SUS plate 11 using double-sided tape measuring 25 mm x 25 mm (width x length). The double-sided tape used is a 200 μm thick double-sided adhesive tape with a PET substrate and an acrylic adhesive layer on both sides. Specifically, for example, "4965" manufactured by Tesa Corporation may be used. In this manner, a structure 14 is produced, which includes two SUS plates 11 and 12 and a thermally expandable fire-resistant material 13 attached to the surface of one of the two SUS plates. In the case of a thermally expandable fire-resistant material having a surface layer material on one side, as described below, the surface opposite the surface layer material is attached to the surface of the SUS plate 11 with double-sided tape. In the case of a thermally expandable fire-resistant material having surface layer materials on both sides or no surface layer material, any one side may be attached to the surface of the SUS plate 11 with double-sided tape.Next, the structure 14 prepared as described above is heated at 500° C. for 15 minutes. Upon heating, the thermally expandable fireproof material 13 expands, and the space between the SUS plates 11 and 12 is closed, as shown in FIG. 2. In this manner, a shear load measurement sample 15 is prepared.

[0014] The maximum shear load is measured using the shear load measurement sample 15 prepared as described above. The maximum shear load is measured by a tensile test in which the SUS plate 11 and the SUS plate 12 of the shear load measurement sample 15 are pulled in the shear direction. Specifically, the SUS plate 11 is fixed, and a tensile test is performed in which the SUS plate 12 is pulled at a rate of 3 mm / min. The tensile test is performed at 25°C. The failure mode of the expansion residue observed during the tensile test and the maximum value of the shear load measured when the expansion residue breaks are defined as the maximum shear load. A larger maximum shear load means that the residue of the expanded expansion layer has better adhesiveness and therefore better fire resistance.

[0015] (Expansion Ratio (Free Expansion Test)) The thermally expandable fireproof material of the present invention is preferably such that, when the thermally expandable fireproof material is cut into a size (width x length) of 25 mm x 25 mm, the cut piece of thermally expandable fireproof material is placed on the surface of an SUS plate, and heated at 600°C for 10 minutes, the expansion ratio of the thermally expandable fireproof material is 25 times or more. When the thermally expandable fireproof material has an expansion ratio of 25 times or more, the thermally expandable fireproof material has good expansion characteristics that enable it to close gaps in the event of a fire, and is excellent in fire resistance. From this viewpoint, the expansion ratio of the thermally expandable fireproof material is more preferably 28 times or more, and even more preferably 30 times or more. The upper limit of the expansion ratio of the thermally expandable fireproof material is not particularly limited, but is, for example, 90 times.

[0016] (Aspect Ratio (Free Expansion Test)) The thermally expandable fireproof material of the present invention is preferably such that, when the thermally expandable fireproof material is cut to dimensions (width x length) of 25 mm x 25 mm, the cut piece is placed on the surface of a stainless steel plate, and heated at 600°C for 10 minutes, the aspect ratio (VW / HW) of the thermally expandable fireproof material's horizontal expansion width (HW) of the SUS plate to the vertical expansion width (VW) of the SUS plate is 1.3 or less. An aspect ratio of 1.3 or less provides horizontal expansion and excellent expansion characteristics that can close gaps in the event of a fire, resulting in excellent fire resistance. From this perspective, the aspect ratio of the thermally expandable fireproof material is more preferably 1.27 or less, and even more preferably 1.25 or less. The lower limit of the aspect ratio of the thermally expandable fireproof material is not particularly limited, but is, for example, 0.5. The expansion width refers to the amount of expansion of the thermally expandable refractory material after heating.

[0017] (Expansion Ratio (Occluded Expansion Test)) The thermally expandable fireproof material of the present invention is prepared by cutting the material to a size (width x length) of 25 mm x 25 mm, attaching the cut piece of the thermally expandable fireproof material to the surface of one of two facing SUS plates at a distance three times the thickness of the expansion layer of the thermally expandable fireproof material, and heating the material at 300°C for 10 minutes. When the area of ​​the fireproof material as viewed vertically from the SUS plate (hereinafter also referred to as the "area after heating") is preferably at least 3.0 times the area of ​​the fireproof material before heating (hereinafter also referred to as the "area before heating"). By making the area after heating at least 3.0 times the area before heating, the performance of the fireproof material can be fully exhibited, for example, when the fireproof material is placed in a space that is narrow in the thickness direction. From this perspective, the area after heating is more preferably at least 3.05 times the area before heating, and even more preferably at least 4.0 times. Furthermore, the area after heating is not particularly limited, but from the viewpoint of ensuring a certain degree of hardness in the event of a fire and making it easier to exhibit fire prevention performance, it is preferably 15 times or less, more preferably 10 times or less, and even more preferably 7 times or less.

[0018] (Temperature Characteristics of Binder Resin and Thermally Expandable Graphite) As for the temperature characteristics of the binder resin and thermally expandable graphite contained in the expansion layer of the thermally expandable fire-resistant material of the present invention, it is preferable that the temperature difference T=X-Y between the thermal decomposition temperature X of the binder resin and the expansion start temperature Y of the thermally expandable graphite is 100°C or more. By having the temperature difference T=X-Y be 100°C or more, it is possible to form an expansion layer that has good expansion characteristics that can close gaps in the event of a fire and whose residue has excellent adhesiveness. From this perspective, the temperature difference T=X-Y is more preferably 105°C or more, and even more preferably 110°C or more. The upper limit of the temperature difference T=X-Y is not particularly limited, but may be, for example, 150°C, 200°C, or 220°C. In order to set the temperature difference T = X - Y within the above range, the thermal decomposition temperature X of the binder resin is preferably 200 to 500°C, more preferably 220 to 480°C, and even more preferably 240 to 460°C. The expansion onset temperature Y of the thermally expandable graphite is preferably 120 to 300°C, more preferably 140 to 250°C, and even more preferably 150 to 210°C. The thermal decomposition temperature X of the binder resin in this specification can be measured using a thermogravimetric differential thermal analyzer (TG-DTA). The expansion onset temperature of the thermally expandable graphite can be measured by raising the temperature of the thermally expandable graphite at a constant temperature using an apparatus with a temperature control function and a function for measuring normal direction force, and measuring the temperature at which the normal direction force rises. The measuring apparatus is not limited as long as it is capable of controlling the measurement temperature and measuring normal direction stress, but a rheometer, for example, can be used.

[0019] (Binder Resin) The expansion layer constituting the thermally expandable fire-resistant material of the present invention contains a binder resin. The binder resin preferably contains a thermosetting resin, more preferably an epoxy resin. By using an epoxy resin as the binder resin, it becomes easier to form an expansion layer that has good expansion properties that can close gaps in the event of a fire and whose residue has excellent adhesiveness. The binder resin of the expansion layer is not particularly limited, but from the viewpoint of reducing environmental load, it is preferable that the binder resin does not contain halogen in its molecular structure.

[0020] Examples of epoxy resins include epoxy compounds alone, or compounds consisting of an epoxy compound as a main component and a curing agent. Epoxy compounds are compounds having an epoxy group, and specific examples include glycidyl ether types and glycidyl ester types. Glycidyl ether types may be bifunctional or multifunctional (trifunctional or higher). The same applies to glycidyl ester types. Epoxy compounds may contain monofunctional compounds to adjust the degree of crosslinking, etc. Among these, bifunctional glycidyl ether types are preferred.

[0021] Examples of the bifunctional glycidyl ether epoxy compound include alkylene glycols such as polyethylene glycol and polypropylene glycol, neopentyl glycol, 1,6-hexanediol, and hydrogenated bisphenol A. Further examples include aromatic epoxy compounds containing an aromatic ring, such as bisphenol A, bisphenol F, bisphenol AD, ethylene oxide-bisphenol A, and propylene oxide-bisphenol A. Among these, aromatic epoxy compounds such as bisphenol A and bisphenol F are preferred, and it is also preferred to use an aromatic epoxy compound in combination with an aliphatic epoxy compound. It is particularly preferred to use a bisphenol F epoxy compound in combination with an aliphatic epoxy compound. When a bisphenol F epoxy compound and an aliphatic epoxy compound are used in combination, the mixing ratio is not particularly limited, but a mass ratio of aliphatic epoxy compound:bisphenol F epoxy compound of 1:1 to 1:15 is preferred, and a mass ratio of 1:1.2 to 1:10 is more preferred.

[0022] Examples of the glycidyl ester type epoxy compounds include hexahydrophthalic anhydride type, tetrahydrophthalic anhydride type, dimer acid type, p-oxybenzoic acid type, etc. Examples of trifunctional or higher functional glycidyl ether type epoxy compounds include phenol novolac type, orthocresol novolac type, DPP novolac type, dicyclopentadiene phenol type, etc. These epoxy compounds may be used alone or in combination of two or more.

[0023] When an epoxy resin is used as the binder resin, a polyaddition type curing agent may be used. Examples of polyaddition type curing agents include polyamine-based curing agents, acid anhydride-based curing agents, polyphenol-based curing agents, and polymercaptan. The method for curing the epoxy resin is not particularly limited, and can be performed by a known method.

[0024] The content of the curing agent in the expansion layer is preferably within a range of 50 to 150 parts by mass per 100 parts by mass of the epoxy compound. If it is 50 parts by mass or more, the epoxy resin becomes easily cured, and if it is 150 parts by mass or less, an effect corresponding to the amount of curing agent blended can be obtained. The content of the polyaddition type curing agent in the expansion layer is preferably within a range of 40 to 85 parts by mass, more preferably within a range of 45 to 80 parts by mass, and even more preferably within a range of 50 to 75 parts by mass per 100 parts by mass of the epoxy compound.

[0025] As the thermosetting resin, a thermosetting resin other than the above-mentioned epoxy resin may be used. Specifically, a urethane resin, a phenol resin, a urea resin, a melamine resin, an unsaturated polyester resin, a polyimide, etc. may be used. Furthermore, as the binder resin, a resin other than the thermosetting resin may be used, for example, an elastomer resin.

[0026] When a thermosetting resin is used, it is preferable to contain a curing accelerator that accelerates curing. The use of a curing accelerator increases the curing rate, allows the thermally expandable graphite and flame retardant to be cured in an appropriately dispersed state, and improves the adhesiveness of the thermally expandable fire-resistant material. This also makes it easier to increase the maximum shear load described above. Furthermore, when an epoxy resin is used as the binder resin, it is more preferable to use a curing accelerator in addition to the curing agent described above. Examples of curing accelerators for epoxy resins include tertiary amines, imidazoles, Lewis acid complexes, etc., and among these, imidazoles are preferred.

[0027] Examples of imidazoles include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1,2-dimethylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 2,4-diamino-6-(2'-methylimidazolyl-(1'))-ethoxybenzoate ... undecylimidazolyl-(1'))-ethyl-s-triazine, 2,4-diamino-6-(2'-ethyl-4'-methylimidazolyl-(1'))-ethyl-s-triazine, 2,4-diamino-6-(2'-ethyl-4'-methylimidazolyl-(1'))-ethyl-s-triazine, 2,4-diamino-6-(2'-methylimidazolyl-(1'))-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-methylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and the like.

[0028] The content of the curing accelerator in the expansion layer is preferably 0.5 to 10 parts by mass, more preferably 1 to 8 parts by mass, and even more preferably 1.2 to 6 parts by mass, relative to 100 parts by mass of the thermosetting resin (for example, in the case of an epoxy resin, the total amount of the epoxy compound and the curing agent).

[0029] The elastomer resin is not particularly limited, but examples thereof include diene rubbers such as isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), hydrogenated styrene-butadiene copolymer rubber (HSBR), chloroprene rubber (CR), and acrylonitrile-butadiene rubber (NBR); and rubber components such as ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), natural rubber, butyl rubber, chlorinated butyl rubber, chlorosulfonated polyethylene, acrylic rubber, epichlorohydrin rubber, multi-vulcanized rubber, non-vulcanized rubber, silicone rubber, fluororubber, and urethane rubber.

[0030] The elastomer component may also be a thermoplastic elastomer, and specific examples thereof include olefin-based thermoplastic elastomers (TPOs), styrene-based thermoplastic elastomers, ester-based thermoplastic elastomers, amide-based thermoplastic elastomers, vinyl chloride-based thermoplastic elastomers, and combinations thereof.

[0031] TPO is a thermoplastic elastomer that has polyolefins such as polyethylene and polypropylene as hard segments and rubbers such as ethylene-propylene rubber and ethylene-propylene-diene rubber as soft segments.

[0032] Examples of styrene-based thermoplastic elastomers include block copolymers having a polystyrene block as a hard segment, and specific examples thereof include styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene-styrene block copolymer (SES), styrene-ethylene-butylene-styrene block copolymer (SEBS), and styrene-ethylene-propylene-styrene block copolymer (SEPS).

[0033] The above binder resins may be used alone or in combination of two or more. When an elastomer resin is used as the binder resin, it is preferable to use the above rubber component, more preferably a diene rubber, and even more preferably NBR, from the viewpoints of adhesiveness and dimensional stability in a high-temperature environment.

[0034] When NBR is used, the nitrile content of the NBR is not particularly limited, but is preferably 5 to 40% by mass, more preferably 10 to 35% by mass, and even more preferably 15 to 25% by mass. The Mooney viscosity ML(1+4) of the NBR at 100°C is preferably 20 to 90, more preferably 30 to 80, and even more preferably 40 to 70. It is also preferable to use two types of NBR in combination, such as NBR (1) and NBR (2) having a higher Mooney viscosity than NBR (1). In this case, the Mooney viscosity ML(1+4) of NBR (1) at 100°C is preferably 20 to 60, more preferably 25 to 50, and even more preferably 30 to 45. Meanwhile, the Mooney viscosity ML(1+4) of NBR (2) at 100°C is preferably 50 to 90, more preferably 55 to 85, and even more preferably 60 to 80. By using two types of NBR with different Mooney viscosities, it becomes easier to ensure adhesiveness while ensuring mechanical strength, and to increase the maximum shear load. When NBR (1) and NBR (2) are used in combination, the mass ratio thereof (NBR (1) / NBR (2)) is preferably 30 / 70 to 95 / 5, more preferably 40 / 60 to 90 / 10, and even more preferably 50 / 50 to 85 / 15. The Mooney viscosity ML(1+4) is measured in accordance with JIS K6300.

[0035] Furthermore, the content of the binder resin is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, based on the total amount of the expandable layer. The content of the binder resin is preferably 45% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less, based on the total amount of the expandable layer. When the content of the binder resin is equal to or greater than the lower limit, the shape retention of the expandable layer is likely to be improved. When the content of the binder resin is equal to or less than the upper limit, the content of thermally expandable graphite can be increased, and fire resistance is likely to be improved.

[0036] (Thermally Expandable Graphite) The expandable layer constituting the thermally expandable fireproof material of the present invention contains thermally expandable graphite. Thermally expandable graphite is a conventionally known substance that expands upon heating, and is obtained by treating raw material powder such as natural flaky graphite, pyrolytic graphite, or kish graphite with a strong oxidizing agent to produce a graphite intercalation compound. Examples of strong oxidizing agents include inorganic acids such as concentrated sulfuric acid, nitric acid, and selenic acid, concentrated nitric acid, perchloric acid, perchlorates, permanganates, dichromates, and hydrogen peroxide. Thermally expandable graphite is a crystalline compound that maintains the layered structure of carbon. The thermally expandable graphite may be neutralized. That is, the thermally expandable graphite obtained by treating with a strong oxidizing agent as described above may be further neutralized with ammonia, aliphatic lower amines, alkali metal compounds, alkaline earth metal compounds, or the like.

[0037] The content of thermally expandable graphite in the expansion layer is preferably 40 to 300 parts by mass, more preferably 50 to 250 parts by mass, and even more preferably 60 to 200 parts by mass, per 100 parts by mass of the binder resin. When the content of thermally expandable graphite is equal to or greater than the above-mentioned lower limit, it becomes easier to increase the expansion pressure of the thermally expandable fire-resistant material, and it becomes easier to adjust the expansion ratio within a desired range. On the other hand, when the content of thermally expandable graphite is equal to or less than the above-mentioned upper limit, it becomes easier to adjust the maximum shear load of the fire-resistant material to the above-mentioned desired value, and it becomes possible to provide excellent adhesion and prevent a decrease in fire resistance.

[0038] (Flame retardant) The expandable layer may contain a flame retardant. By containing a flame retardant, the thermally expandable fire-resistant material can be imparted with flame retardancy, and the performance of the fire-resistant material can be more effectively exhibited. The flame retardant used in the present invention preferably contains one that is solid at room temperature (23°C) and normal pressure (1 atmosphere), and more preferably contains a phosphorus-based solid flame retardant.

[0039] The phosphorus-based solid flame retardant is a compound that becomes solid at room temperature (23° C.) and atmospheric pressure (1 atmosphere), and specific examples thereof include phosphates, phosphazene compounds, phosphoric acid ester compounds, and metal phosphinates.

[0040] Specific examples of phosphates include monophosphates, polyphosphates, etc. The term "phosphates" as used herein includes not only orthophosphates but also phosphites, hypophosphites, etc. The same applies to polyphosphates. Examples of monophosphates include ammonium salts such as ammonium phosphate, ammonium dihydrogen phosphate, and diammonium hydrogen phosphate; sodium salts such as monosodium phosphate, disodium phosphate, trisodium phosphate, monosodium phosphite, disodium phosphite, and sodium hypophosphite; potassium salts such as monopotassium phosphate, dipotassium phosphate, tripotassium phosphate, monopotassium phosphite, dipotassium phosphite, and potassium hypophosphite; lithium salts such as monolithium phosphate, dilithium phosphate, trilithium phosphate, monolithium phosphite, dilithium phosphite, and lithium hypophosphite; barium salts such as barium dihydrogen phosphate, barium hydrogen phosphate, tribarium phosphate, and barium hypophosphite; magnesium salts such as magnesium monohydrogen phosphate, magnesium hydrogen phosphate, trimagnesium phosphate, and magnesium hypophosphite; calcium salts such as calcium dihydrogen phosphate, calcium hydrogen phosphate, tricalcium phosphate, and calcium hypophosphite; zinc salts such as zinc phosphate, zinc phosphite, and zinc hypophosphite; and aluminum salts such as aluminum monophosphate, aluminum diphosphate, aluminum triphosphate, and aluminum hypophosphite. Among these, ammonium phosphate and aluminum phosphite are preferred, and aluminum phosphite is more preferred. Examples of polyphosphates include ammonium polyphosphate, piperazine polyphosphate, melamine polyphosphate, ammonium amide polyphosphate, and aluminum polyphosphate, with ammonium polyphosphate being preferred among these.

[0041] A phosphazene compound is an organic compound in which phosphorus atoms and nitrogen atoms are alternately bonded. Examples of the phosphazene compound include cyclic phosphazene compounds, chain phosphazene compounds, and crosslinked phosphazene compounds crosslinked by a crosslinking group. Specific examples of the phosphazene compound include those containing a structural unit represented by the following general formula (1):

[0042] In the general formula (1), each X independently represents an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 12 carbon atoms, an amino group, or a halogen atom. In the general formula (1), examples of the substituent on the aryl group include an alkyl group, an amino group, and a halogen atom. Each X independently represents preferably a phenyl group, a substituted phenyl group, a phenyloxy group, or a substituted phenyloxy group, and more preferably a phenyl group or a phenyloxy group.

[0043] The phosphate ester compound is not particularly limited as long as it is solid at room temperature (23°C), and examples thereof include monophosphate esters and condensed phosphate esters. These phosphate ester compounds may be commercially available products. Examples of monophosphate esters include triphenyl phosphate and tris(tribromoneopentyl)phosphate. Commercially available monophosphate esters include "TPP," "CR-900," and "DAIGUARD-1000" (all manufactured by Daihachi Chemical Industry Co., Ltd.). The condensed phosphate ester may be a halogen-containing condensed phosphate ester, or a halogen-free condensed phosphate ester. More specifically, examples include alkyl-substituted aromatic condensed phosphate esters such as 1,3-phenylenebis(di-2,6-xylenyl phosphate).

[0044] The metal phosphinate is a metal salt of an organic phosphinic acid. Specific examples of the metal phosphinate include aluminum trisdiethylphosphinate, aluminum trismethylethylphosphinate, aluminum trisdiphenylphosphinate, zinc bisdiethylphosphinate, zinc bismethylethylphosphinate, zinc bisdiphenylphosphinate, titanyl bisdiethylphosphinate, titanium tetrakisdiethylphosphinate, titanyl bismethylethylphosphinate, titanium tetrakismethylethylphosphinate, titanyl bisdiphenylphosphinate, and titanium tetrakisdiphenylphosphinate.

[0045] The flame retardant may contain a flame retardant other than the above-mentioned phosphorus-based solid flame retardant, such as a red phosphorus-based flame retardant, a boron-containing flame retardant, a bromine-based flame retardant, an antimony-containing flame retardant, a metal hydroxide, a low-melting glass, a needle-like filler, etc. The flame retardant may be used alone or in combination of two or more.

[0046] The content of the flame retardant in the expandable layer is preferably 30 to 200 parts by mass, more preferably 40 to 150 parts by mass, and even more preferably 50 to 100 parts by mass, per 100 parts by mass of the binder resin. When the content of the flame retardant is equal to or greater than the lower limit, the fire resistance of the fire-resistant material is likely to be improved. On the other hand, when the content of the flame retardant is equal to or less than the upper limit, the flame retardant is likely to be uniformly dispersed in the resin, resulting in excellent moldability.

[0047] (Filler) The expandable layer may further contain a filler other than the flame retardant and thermally expandable graphite. The filler other than the flame retardant and thermally expandable graphite is not particularly limited, and examples thereof include metal carbonates such as alumina, basic magnesium carbonate, calcium carbonate, magnesium carbonate, zinc carbonate, strontium carbonate, and barium carbonate, silica, diatomaceous earth, dawsonite, barium sulfate, talc, clay, mica, montmorillonite, bentonite, activated clay, sepiolite, imogolite, sericite, glass fiber, glass beads, silica-based balloons, aluminum nitride, boron nitride, silicon nitride, carbon black, graphite, carbon fiber, carbon balloons, charcoal powder, various metal powders, potassium titanate, magnesium sulfate, lead zirconate titanate, aluminum borate, molybdenum sulfide, silicon carbide, stainless steel fiber, various magnetic powders, slag fiber, fly ash, and dewatered sludge. These fillers may be used alone or in combination of two or more.

[0048] The average particle size of the filler is preferably 0.5 to 100 μm, more preferably 1 to 50 μm. When the content of the filler is small, a small particle size is preferred from the viewpoint of improving dispersibility, but when the content is large, as the filling rate increases, the viscosity of the refractory material increases and the moldability decreases, so a large particle size is preferred.

[0049] When the expandable layer contains a filler, the content of the filler is preferably 10 to 200 parts by mass, more preferably 40 to 200 parts by mass, and even more preferably 50 to 150 parts by mass, relative to 100 parts by mass of the binder resin. When the content of the filler is within the above range, the mechanical properties of the expandable layer are likely to be improved.

[0050] (Plasticizer) The expandable layer may contain a plasticizer. By containing a plasticizer, a certain degree of flexibility or conformability is imparted to the thermally expandable fireproof material, and for example, when attached to a building or fixture, the expandable layer can easily conform to the irregularities on the surface of the building or fixture. In addition, the adhesiveness of the expansion residue to the surface of the building or fixture is easily increased, and the maximum shear load is also easily increased. A plasticizer can be suitably used when an elastomer resin is used as the binder resin. The plasticizer is not particularly limited, but examples thereof include phthalic acid-based plasticizers, adipic acid-based plasticizers, phosphoric acid-based plasticizers, and alkylsulfonic acid-based plasticizers.

[0051] Examples of phthalic acid plasticizers include di-2-ethylhexyl phthalate (DOP), di-n-octyl phthalate, diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), diundecyl phthalate (DUP), and phthalate esters of higher alcohols or mixed alcohols having about 10 to 13 carbon atoms. 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), and adipic acid polyesters.

[0052] Examples of phosphoric acid plasticizers include trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, octyl diphenyl phosphate, tributoxyethyl phosphate, trichloroethyl phosphate, tris(2-chloropropyl)phosphate, tris(2,3-dichloropropyl)phosphate, tris(2,3-dibromopropyl)phosphate, tris(bromochloropropyl)phosphate, bis(2,3-dibromopropyl)-2,3-dichloropropyl phosphate, bis(chloropropyl)monoctyl phosphate, tris(2-ethylhexyl)phosphate, triphenyl phosphate, tricresyl phosphate (TCP), trixylenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, and 2-ethylhexyl diphenyl phosphate. Examples of the alkylsulfonic acid plasticizer include alkylsulfonic acid phenyl ester and N-butylbenzenesulfonamide.

[0053] Adipic acid plasticizers or alkylsulfonic acid plasticizers are preferred, and among them, when an elastomer resin is used as the binder resin, alkylsulfonic acid plasticizers are more preferred. Furthermore, among alkylsulfonic acid plasticizers, alkylsulfonic acid phenyl esters are even more preferred.

[0054] When the expandable layer contains a plasticizer, the content of the plasticizer is not particularly limited, but is preferably 5 to 100 parts by mass, more preferably 10 to 70 parts by mass, and even more preferably 15 to 50 parts by mass, relative to 100 parts by mass of the binder resin.

[0055] (Tackifier) ​​The expansion layer may contain a tackifier. By including a tackifier in the expansion layer, the adhesiveness of the expansion layer is enhanced, and the maximum shear load described above is also likely to increase. Tackifiers are preferably used when an elastomer resin is used as the binder resin. When an elastomer resin is used as the binder resin, the expansion layer preferably contains both a plasticizer and a tackifier. Examples of tackifiers include petroleum-based resins such as aliphatic copolymers, aromatic copolymers, aliphatic-aromatic copolymers, and alicyclic copolymers; coumarone-indene-based compounds; terpene-based resins; terpene-phenol-based compounds; rosin-based compounds; (alkyl)phenol-based resins; and xylene-based compounds. Among these, petroleum-based resins are preferred. The content of the tackifier in the expansion layer is preferably 2 to 50 parts by mass, more preferably 5 to 40 parts by mass, and even more preferably 10 to 30 parts by mass, per 100 parts by mass of the binder resin.

[0056] (Other Additives) The expandable layer may contain various additive components 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 vulcanizing agents, vulcanization accelerators, shrinkage inhibitors, crystal nucleating agents, colorants (pigments, dyes, etc.), ultraviolet absorbers, antioxidants, antiaging agents, dispersants, gelling accelerators, fillers, reinforcing agents, flame retardant assistants, antistatic agents, surfactants, and surface treatment agents. The amount of additive added can be appropriately selected within a range that does not impair moldability, etc. The additives may be used alone or in combination of two or more.

[0057] (Surface Layer Material) The thermally expandable fireproof material of the present invention may have a surface layer material provided on one or both surfaces of the expandable layer from the viewpoint of improving the appearance, improving scratch resistance, etc. The surface layer material may be provided on only one surface of the expandable layer or on both surfaces of the expandable layer, but is preferably provided on only one surface of the expandable layer.

[0058] The surface layer material preferably contains at least plastic, and more preferably contains at least one selected from the group consisting of polyester resins such as polyethylene terephthalate (PET), polyvinyl chloride (PVC) resins, polyurethane resins, polyolefin resins such as polyethylene (PE) and polypropylene (PP), polycarbonate resins, polyamides, and acrylic resins, with PET being even more preferred. The surface layer material is preferably a plastic film made from the above plastics, and PET film is particularly preferred. The plastic film may be a stretched film or a non-stretched film, but from the viewpoint of mechanical strength, a stretched film is preferred, and a biaxially stretched film is particularly preferred.

[0059] The surface layer material may also include a fibrous structure. By using a fibrous structure, the binder resin of the expandable layer penetrates between the fibers, improving adhesion to the expandable layer and facilitating the improvement of the dimensional stability of the thermally expandable fire-resistant material in a high-temperature environment. Examples of the fibrous structure include knitted fabric, woven fabric, and nonwoven fabric, with woven fabric and nonwoven fabric being preferred. Examples of fibers used in the fibrous structure include glass fiber, ceramic fiber, cellulose fiber, polyester fiber, carbon fiber, and graphite fiber.

[0060] The surface layer material may also be a fiber-plastic composite material, such as one formed by impregnating a fiber layer with plastic, for example, a composite formed by laminating a plastic layer on a fiber layer and partially impregnating the plastic layer. PET glass cloth is a preferred fiber-plastic composite material. When using a fiber-plastic composite material as the surface layer material, it is preferable to arrange the fiber layer on the expansion layer side and the plastic layer on the outside. This configuration allows the appearance of the heat-expandable fire-resistant material to be maintained in good condition. Furthermore, impregnating the fiber layer with the expansion layer facilitates laminating the surface layer material and the expansion layer with high adhesion. Among the above-mentioned materials, a plastic film is preferred as the surface layer material. By using a plastic film, the surface layer melts when the heat-expandable fire-resistant material is heated to a high temperature and expands, thereby facilitating adhesion of the expansion layer to the surface of the building fixture, etc. This also facilitates increasing the maximum shear load described above.

[0061] The melting point of the surface layer material is preferably 180°C or higher, more preferably 200°C or higher, and even more preferably 220°C or higher. Furthermore, the melting point of the surface layer material is preferably 320°C or lower, more preferably 300°C or lower, and even more preferably 280°C or lower. Therefore, when the surface layer material is a plastic film, the melting point of the plastic constituting the surface layer material should be within the above range. When the melting point of the surface layer material is within the above range, it becomes easier to obtain a thermally expandable fire-resistant material that has good expansion properties that can close gaps in the event of a fire and leaves a residue with excellent adhesiveness.

[0062] (Adhesive Layer) The heat-expandable fire-resistant material of the present invention may further include an adhesive layer. The adhesive layer facilitates the attachment of the heat-expandable fire-resistant material to an adherend such as a building fixture. For example, when the heat-expandable fire-resistant material includes a surface layer material on only one side of the expansion layer, the adhesive layer may be provided on the side of the expansion layer opposite the surface layer material. Therefore, the heat-expandable fire-resistant material preferably has a layer structure of surface layer material / expansion layer / adhesive layer. Furthermore, when attaching the heat-expandable fire-resistant material to an adherend such as a building fixture, the expansion layer may be attached so that it contacts the adherend via the adhesive layer. Note that when the heat-expandable fire-resistant material includes surface layer materials on both sides of the expansion layer, an adhesive layer may be provided on either side. The adhesive layer is not particularly limited, and a commonly used adhesive may be used. Examples of the adhesive layer include acrylic adhesives, silicone adhesives, urethane adhesives, and rubber adhesives. Among these, acrylic adhesives are preferred. The adhesive layer may be a single adhesive layer made of an adhesive, or may be a double-sided tape in which adhesive layers are provided on both sides of a surface material. The thickness of the adhesive layer is, for example, 10 to 500 μm, and preferably 50 to 300 μm.

[0063] (Method for Producing Fire-Resistant Material) The thermally expandable fire-resistant material of the present invention can be produced, for example, as follows. First, thermally expandable graphite, a binder resin, and optionally, a catalyst, a flame retardant, a plasticizer, a filler, and other additives are mixed in a kneader such as a kneading roll or a stirring device to obtain a fire-resistant resin composition. The temperature during mixing and the temperature for forming into a sheet are preferably lower than the expansion initiation temperature of the thermally expandable graphite. Therefore, the mixing temperature is preferably 30 to 100°C, more preferably 40 to 80°C. The temperature for forming into a sheet is preferably 70 to 110°C, more preferably 80 to 100°C. Next, the obtained fire-resistant resin composition is applied to a substrate to form a sheet, thereby obtaining an expansion layer laminated on the substrate. The expansion layer laminated on the substrate may be configured as only the expansion layer by peeling off the substrate, or may be configured as a surface layer without peeling off the substrate. Alternatively, another substrate may be laminated on the expandable layer laminated on the substrate, so that the expandable layer has substrates (surface layer materials) on both sides thereof. When the expandable layer has substrates (surface layer materials) on both sides thereof, the substrates (surface layer materials) on both sides of the expandable layer may be the same or different, but are preferably the same.

[0064] (Shape, Thickness) The thermally expandable fireproof material of the present invention is preferably in the form of a sheet, more preferably a rectangular sheet. The thickness is not particularly limited, but from the viewpoints of fire resistance and ease of handling, it is preferably 0.3 to 5 mm, more preferably 0.5 to 4 mm, and even more preferably 1 to 3 mm. The thickness ratio of the expandable layer to the substrate (surface layer material) is preferably 2 to 80, more preferably 5 to 50, and even more preferably 10 to 40. The thickness of the substrate (surface layer material) is preferably 50 to 300 μm, more preferably 70 to 200 μm. The thickness of the expandable layer before heating is preferably 0.2 to 4 mm, more preferably 0.4 to 3 mm, and even more preferably 0.9 to 2.5 mm. When the thickness ratio and the thickness of the thermally expandable fireproof material and each layer are within the above ranges, the material has good expansion properties that can close gaps in the event of a fire, and the residue tends to have excellent adhesive properties.

[0065] (Wound body) The thermally expandable fireproof material of the present invention is preferably wound into a wound body. By forming it into a wound body, transportation efficiency is improved, and a large amount of thermally expandable fireproof material can be transported at once, for example, to a construction site of a building. Furthermore, it becomes possible to store a large amount of thermally expandable fireproof material in a limited area, for example, in a warehouse. In the wound body, the thermally expandable fireproof material preferably has a length of 10 m or more, and in this case, the sheet width is preferably, for example, 0.01 to 2.0 m. Furthermore, the upper limit of the length is not particularly limited, and it may be 500 m or less.

[0066] (Uses) The thermally expandable fireproof material of the present invention can be used specifically for various fittings in detached houses, apartment buildings, high-rise houses, high-rise buildings, commercial facilities, public facilities, etc., various vehicles such as automobiles and trains, ships, and aircraft, among which it is preferably used for fittings. Specific examples of fittings that can be used include, but are not limited to, walls, beams, pillars, floors, bricks, roofs, boards, windows, shoji screens, doors, sliding doors, transoms, wiring, and piping. The thermally expandable fireproof material of the present invention can be applied, in particular, to gaps in fittings such as windows and doors, to prevent flames from penetrating through the gaps in the event of a fire or the like.

[0067] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0068] [Evaluation Method] (1) Shear Test This will be explained with reference to Figures 1 and 2. The thermally expandable fireproof material produced in each Example and Comparative Example was cut to a size (width x length) of 25 mm x 25 mm to prepare a thermally expandable fireproof material 13 as a sample for a shear test. Next, two SUS plates 11 and 12 were prepared. Each SUS plate had a thickness of 0.3 mm, a width of 50 mm, and a length of 100 mm. The two SUS plates 11 and 12 were arranged facing each other at a distance of 6 mm, which is three times the thickness (2 mm) of the expansion layer of the thermally expandable fireproof material 13. The SUS plates were also arranged so that the opposing area between them was 50 mm x 50 mm. Next, the thermally expandable fireproof material 13 cut to 25 mm x 25 mm and having a thickness of 2 mm was attached to the surface of one of the SUS plates 11 near the center. The attachment was performed using a 200 μm-thick double-sided tape ("4965" manufactured by Tesa). In the case of a thermally expandable fireproof material having a surface layer material on one side, the surface opposite the surface layer material was attached to the surface of the SUS plate 11 using an acrylic adhesive. In this manner, a structure 14 was produced, including two SUS plates 11 and 12, and a thermally expandable fireproof material 13 attached to the surface of one of the two SUS plates. The structure 14 thus prepared was heated in an electric furnace at 500°C for 15 minutes, thereby expanding the thermally expandable fireproof material 13 and closing the gap between the SUS plates 11 and 12, as shown in FIG. 2 , to produce a shear load measurement sample 15. A tensile test was performed in which the SUS plates 11 and 12 of the shear load measurement sample 15 thus prepared were pulled in the shear direction. Specifically, a tensile test was performed in which the SUS plate 11 was fixed and the SUS plate 12 was pulled at a speed of 3 mm / min. The tensile tester used was a "Tensilon RTC1210A" manufactured by Orientec Co., Ltd., and the measurement temperature was 25°C. The tensile condition in the tensile test was 3 mm / min. The fracture mode of the expansion residue observed during the tensile test and the maximum value of the shear load measured at that time were defined as the maximum shear load (N).

[0069] (2) Expansion Ratio and Aspect Ratio (Free Expansion Test) The 2 mm thick thermally expandable refractory material prepared in each Example and Comparative Example was cut to a size (width x length) of 25 mm x 25 mm. The cut thermally expandable refractory material was placed on the surface of a SUS plate (0.3 mm thick, 50 mm wide, 100 mm long) and heated in an electric furnace at 600°C for 10 minutes. The expansion ratio was determined by dividing the thickness of the thermally expandable refractory material after heating by the thickness of the thermally expandable refractory material before heating. The aspect ratio (VW / HW) of the vertical expansion width (VW) of the SUS plate to the horizontal expansion width (HW) of the thermally expandable refractory material after heating was also determined. The expansion width refers to the amount of expansion of the thermally expandable refractory material after heating.

[0070] (3) Expansion Ratio (Occluded Expansion Test) Two SUS plates (0.3 mm thick, 100 mm wide, 100 mm long) were arranged so that the opposing area was 100 mm x 100 mm. A thermally expandable fireproof material cut to the above dimensions (width x length) of 25 mm x 25 mm was attached to the center of the surface of one of the two SUS plates in the same manner as in (1) Shear Test to prepare a structure. The prepared structure was heated in an electric furnace at 300 ° C. for 10 minutes. The expansion ratio was calculated by dividing the area of ​​the thermally expandable fireproof material after heating by the area of ​​the thermally expandable fireproof material before heating.

[0071] (4) Temperature Characteristics The thermal decomposition temperature X of the binder resin used in each example and comparative example was measured using a thermogravimetric differential thermal analyzer (TG-DTA, manufactured by Hitachi High-Technologies Corporation). The thermal decomposition temperature X was determined by performing a thermogravimetric differential thermal analysis on the expandable layer, and the temperature at which the thermal decomposition of the binder resin began was taken as the thermal decomposition temperature X. The thermogravimetric differential thermal analysis was performed under conditions of a temperature increase of 10°C / min from 40°C to 1,000°C. The expansion start temperature Y of the thermally expandable graphite was measured using the method described in the specification. The temperature difference T = X - Y was calculated from the measured thermal decomposition temperature X of the binder resin and the expansion start temperature Y of the thermally expandable graphite.

[0072] The components used in each example and comparative example are as follows: (Binder Resin) 1. Thermosetting Resin Epoxy Resin (1) "jER807" manufactured by Mitsubishi Chemical Corporation, bisphenol F type epoxy resin Epoxy Resin (2) "EX830" manufactured by Nagase ChemteX Corporation, aliphatic epoxy resin Curing Agent (1) "FL052" manufactured by Mitsubishi Chemical Corporation, polyamine-based curing agent Curing Agent (2) "FL079" manufactured by Mitsubishi Chemical Corporation, polyamine-based curing agent 2. Elastomer Components NBR (1) "Nipol DN401LL" manufactured by Nippon Zeon Corporation, Mooney viscosity ML (1+4): 32, nitrile content 18% by mass NBR (2) "Nipol DN401" manufactured by Nippon Zeon Corporation, Mooney viscosity ML (1+4): 77.5, nitrile content 18% by mass

[0073] (Curing accelerator) 1,2-dimethylimidazole (1,2-DMZ) "Curezol 1.2DMZ" manufactured by Shikoku Chemicals Corporation 2-ethyl-4-methylimidazole (2E4MEZ) "Curezol 2E4MZ" manufactured by Shikoku Chemicals Corporation

[0074] (Thermal Expandable Graphite) Thermal Expandable Graphite (1) "CA-60N" manufactured by Air Water Corporation, expansion start temperature 200°C Thermal Expandable Graphite (2) "EXP-50S150" manufactured by Fuji Graphite Industries Co., Ltd., expansion start temperature 150°C

[0075] (Flame retardant) Ammonium polyphosphate "AP422" manufactured by Clariant Aluminum phosphite "NSF" manufactured by Taihei Chemical Industry Co., Ltd.

[0076] (Filler) Calcium carbonate "Whiten BF-300" manufactured by Bihoku Funka Kogyo Co., Ltd. Barium sulfate "FBA" manufactured by Taihei Talc Co., Ltd.

[0077] (Tackifier) ​​Alicyclic petroleum resin "P-125" manufactured by Arakawa Chemical Industries, Ltd.

[0078] (Plasticizer) Alkyl sulfonic acid phenyl ester "Mezamol" manufactured by LANXESS

[0079] (Surface material) ・PET film "Lumirror #75-S10" manufactured by Toray Industries, Inc., thickness 75 μm ・Glass cloth and PET laminated film (GC / PET) "EP11" manufactured by Maeda Glass Co., Ltd., thickness 100 μm and "Mat Lumirror" manufactured by Tokyo Film Services Co., Ltd., thickness 80 μm, laminated with acrylic adhesive, thickness 180 μm ・Nonwoven fabric "SPC" manufactured by Nippon Paper Papylia Co., Ltd., thickness 10 μm ・Glass cloth film (GC) "EP11" manufactured by Maeda Glass Co., Ltd., thickness 100 μm

[0080] [Example 1] The binder resin, curing agent, curing accelerator, thermally expandable graphite, flame retardant, and filler were fed to a planetary mixer according to the formulation shown in Table 1 and kneaded at room temperature at 1,000 rpm for 1 minute to obtain a fire-resistant resin composition. The fire-resistant resin composition was then applied to a release film substrate and press-molded at room temperature under 10 MPa to obtain a sheet-like molded product having a thickness of 2.0 mm. The molded product was then placed in a thermostatic chamber at 100°C for 10 hours to cure, and the release film was removed to obtain a sheet-like heat-expandable fire-resistant material. The evaluation results are shown in Table 1.

[0081] [Examples 2 to 6, Comparative Examples 1 to 4] Thermally expandable fire-resistant materials were produced in the same manner as in Example 1, except that the formulation of the expandable layer was changed as shown in Table 1, and the substrate was changed from a release film to one shown in Table 1, and the film was used as the surface layer material without being peeled off.

[0082] [Example 7] A binder resin, thermally expandable graphite, a flame retardant, and other additives were placed in a roll and kneaded at 90°C for 15 minutes according to the formulation shown in Table 1 to obtain a fire-resistant resin composition. The obtained fire-resistant resin composition was press-molded at 100°C for 1 minute to obtain a sheet-like expansion layer having a thickness of 2.0 mm, and this expansion layer was used as a heat-expandable fire-resistant material. The evaluation results are shown in Table 1.

[0083] [Examples 8 to 10, Comparative Examples 5 and 6] A binder resin, thermally expandable graphite, a flame retardant, and other additives were placed in a roll and kneaded at 90°C for 15 minutes according to the formulation shown in Table 1 to obtain a fire-resistant resin composition. The obtained fire-resistant resin composition was press-molded at 100°C for 1 minute to obtain a sheet-like expansion layer having a thickness of 2.0 mm. A surface layer material shown in Table 1 was laminated on the expansion layer to obtain a heat-expandable fire-resistant material. The evaluation results are shown in Table 1.

[0084]

[0085] It was found that the thermally expandable fire-resistant materials of each Example had good expansion characteristics capable of sealing gaps in the event of a fire, and the residue had excellent adhesiveness, because the failure mode of the residue of the expansion layer was cohesive failure and the maximum shear load was 10 N or more. In contrast, it was found that the fire-resistant materials of Comparative Examples 1 to 6 had poor adhesiveness of the residue, because the failure mode of the residue of the expansion layer was not cohesive failure, and therefore had poor fire resistance.

[0086] [Evaluation Method] (5) Fire Resistance Test The thermally expandable fire-resistant materials of Examples 1 to 6 and Comparative Examples 1 to 5 were tested in a fire-resistant furnace simulating an actual fire. This test was conducted with reference to ISO 12472:2003, "Fire Resistance of Wooden Fire Doors - Method for Evaluating the Effectiveness of Thermally Expandable Sealing Materials." First, as shown in Figures 3(a) and (b), a test specimen 20 was prepared, which had a shoji screen portion 22 inside a test specimen frame 21. As shown in Figure 3(b), the shoji screen portion 22 located inside the test specimen frame 21 was rotated by a rod (rotation axis) 23 passing from the upper right to the lower left of the test specimen frame 21. A stopper 24 provided on a portion of the shoji screen portion 22 allowed the shoji screen portion 22 to rotate and stop. Furthermore, the load applied to the rotation could be controlled by hanging an optional weight 26 from a wire 25 provided on a portion of the shoji screen portion 22. A fire resistance test was conducted by attaching a heat-expandable fire-resistant material 27 to two sides of the gap between the specimen frame 21 and the shoji screen portion 22. The gap between the specimen frame 21 and the shoji screen portion 22 was constructed with opposing steel members to increase the strength of the specimen 20 and evaluate the thermal expansion characteristics of the heat-expandable fire-resistant material. The fire resistance test was conducted under heating conditions compliant with ISO. The stopper 24 was released 15 minutes after the start of the test, and a 7.5 kg weight 26 was hung from the wire 25 30 minutes after the start of the test. The amount of displacement and time by which the side of the shoji screen portion 22 on which the heat-expandable fire-resistant material 27 was placed was measured, relative to the specimen frame 21. For safety reasons, the maximum displacement was 25 mm, and the test was terminated when this displacement was reached or after heating for a maximum of 90 minutes.

[0087]

[0088] In the heat-expandable fire-resistant materials of Examples 1 to 6, the residue had excellent adhesiveness, so the displacement after 90 minutes was 16.6 to 23.7 mm. On the other hand, in the heat-expandable fire-resistant materials of Comparative Examples 1 to 5, all of them reached a displacement of 25 mm during the test.

[0089] REFERENCE SIGNS LIST 11 SUS plate 12 SUS plate 13 Thermally expandable fire-resistant material 14 Structure 15 Shear load measurement sample 20 Test specimen 21 Test specimen frame 22 Shoji part 23 Rotating shaft 24 Stopper 25 Wire 26 Weight 27 Thermally expandable fire-resistant material

Claims

1. A thermally expandable fire-resistant material having an expansion layer containing a binder resin and thermally expandable graphite, wherein the thermally expandable fire-resistant material having dimensions of 25 mm x 25 mm is attached to the surface of one of two SUS plates having an area of ​​50 mm x 50 mm and facing each other at a distance three times the thickness of the expansion layer of the thermally expandable fire-resistant material, and then heated at 500°C for 15 minutes to obtain a shear load measurement sample, and in a shear load measurement test measured under tensile conditions of 3 mm / min, the residue of the expansion layer undergoes cohesive failure, and the maximum shear load at that time is 10 N or more.

2. The thermally expandable fire-resistant material according to claim 1, wherein when the thermally expandable fire-resistant material having dimensions of 25 mm x 25 mm is placed on the surface of an SUS plate and heated at 600°C for 10 minutes, the expansion ratio of the thermally expandable fire-resistant material is 25 times or more.

3. A thermally expandable fire-resistant material according to claim 1 or 2, wherein when the thermally expandable fire-resistant material having dimensions of 25 mm x 25 mm is placed on the surface of a stainless steel plate and heated at 600°C for 10 minutes, the aspect ratio (VW / HW) of the thermally expandable fire-resistant material's expansion width in the vertical direction (VW) of the stainless steel plate to the horizontal expansion width (HW) of the stainless steel plate is 1.3 or less.

4. A heat-expandable fire-resistant material according to claim 1 or 2, wherein when the heat-expandable fire-resistant material having dimensions of 25 mm x 25 mm is attached to the surface of one of two opposing SUS plates at a distance three times the thickness of the expansion layer of the heat-expandable fire-resistant material and heated at 300°C for 10 minutes, the area of ​​the heat-expandable fire-resistant material as viewed from the vertical direction of the SUS plates is 3.0 times or more the area of ​​the heat-expandable fire-resistant material before heating.

5. The thermally expandable fire-resistant material according to claim 1 or 2, wherein the temperature difference T=X-Y between the thermal decomposition temperature X of the binder resin and the expansion initiation temperature Y of the thermally expandable graphite is 100°C or more.

6. The thermally expandable fire-resistant material according to claim 1 or 2, wherein the binder resin is a thermosetting resin.

7. The thermally expandable fire-resistant material according to claim 6, wherein the thermosetting resin comprises an epoxy resin.

8. The thermally expandable fire-resistant material according to claim 6, wherein the intumescent layer further comprises a cure accelerator.

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

10. The thermally expandable fire-resistant material according to claim 1 or 2, wherein the thermally expandable fire-resistant material is a wound body having a length of 10 m or more.

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