JP2010031178A - Fireproof joint sealant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology about a fireproof joint sealant reduced in weight and softened while maintaining conventional properties essential to an expansion material for fire prevention. <P>SOLUTION: The fireproof joint sealant includes 100 pts.mass of a urethane prepolymer, 5-19 pts.mass of an epoxy resin, 70-120 pts.mass of an inorganic filler, and 10-30 pts.mass of thermally expansible graphite. In the fireproof joint sealant, when compounding amounts of the epoxy resin and the inorganic filler are intendedly set to such amounts conventionally considered as irrational ones for achieving shape stabilization performance and workability and a compounding amount of the thermally expansible graphite is limited to a specific amount, reduction in weight and softening can be achieved while maintaining properties essential to an expansion material for fire prevention. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fireproof joint material. More specifically, the present invention relates to a fireproof joint material used for a part or all of a clearance of a through-hole provided in a fireproof compartment or a joint of a building assembled by a unit construction method or the like.

  In recent years, in order to reduce the damage of fire as much as possible, between cables such as power cables and communication cables penetrating the fire protection compartment and fire walls, between piping such as air conditioning equipment and fire walls, etc. An expansion material for fire prevention is used as a joint material. The expansion material for fire prevention expands by heating at the time of a fire to form an expansion layer, thereby closing a gap between through holes in the fire prevention compartment to prevent the spread of fire. Therefore, a fireproof joint material made of a fireproof expansion material is required to maintain a predetermined shape for as long as possible without the expansion layer being easily deformed by flame heat, particularly after the formation of the expansion layer.

  As a technique for maintaining a predetermined shape for a long time without causing the expansion layer in the expansion material for fire protection to be deformed by flame heat, for example, in Patent Document 1, an inorganic expansion agent and / or an organic expansion agent is used as a base resin. A resin composition in which a polycarbonate resin, a polyphenylene sulfide resin, a polyether ketone resin, a polyamide resin, a phenol resin, or the like is blended as a shape stabilizing resin has been proposed. However, this composition has a problem that the elasticity and flexibility are not sufficient depending on the use and the workability is poor.

  For example, Patent Document 2 proposes a method for producing a polyurethane imparted with fire resistance as a technique relating to the fireproof expansion material having excellent elasticity and flexibility. This is characterized by blending polyol and polyisocyanate with expansive graphite as a flame retardant and using powdered casein as a shape stabilizer. With this technique, elasticity and flexibility can be improved, but on the other hand, shape stabilization has not been sufficient. Further, in this technique for producing polyurethane from a two-component reaction mixture of polyol and polyisocyanate, it is extremely difficult to blend a large amount of expansive graphite as a flame retardant, and sufficient fire resistance performance cannot be obtained. there were.

  As a technique for improving brittleness and fire resistance, which has been a problem in the past, Patent Document 3 proposes a flexible fireproof rubber joint material composed of rubber, expandable graphite, epoxy resin, and inorganic filler. ing. Although this technology has improved brittleness and fire resistance, there is a problem that the epoxy resin blended to stabilize the shape after expansion adheres to the inner wall of the kneading machine during kneading, and this removal is extremely difficult. .

  Furthermore, as a technique for improving the stabilization of the shape after expansion, for example, Patent Document 4 proposes a composition in which boric acid is added to a flexible urethane foam containing expandable graphite. Although this technique has improved the stabilization of the shape after thermal expansion, there is a problem that the urethane foam may be hydrolyzed when exposed to a high temperature for a long period of time, thereby losing elasticity. Therefore, it was necessary to limit the use under high temperature and high humidity.

  As a technique for improving the problem of loss of elasticity due to hydrolyzability, the present inventors have developed a composition containing an epoxy resin instead of boric acid in the composition of Patent Document 4 (Patent Document). 5). This technique improves long-term durability at high temperatures while maintaining shape retention after thermal expansion.

Japanese Patent Laid-Open No. 09-176498 Japanese National Publication No. 03-504738 JP 2002-181262 A JP 2001-348476 A JP 2006-70155 A

  As described above, various developments have been made regarding the technology related to the fire-resistant expansion material. However, in order to use it as a fire-resistant joint material, the gap between the through holes provided in the fire-proof compartment, the unit construction method, It needs to be inserted into a joint of a building to be assembled and compressed and used, and in order to improve workability, weight reduction and softening are demanded.

  Therefore, the main object of the present invention is to provide a technology relating to a fireproof joint material that can realize weight reduction and softening while maintaining the properties indispensable for conventional fireproof expansion materials.

  In order to solve the above-mentioned problems, the inventors of the present application have conducted intensive research on the blending amounts of each component of the fireproof joint material. In order to give, by darely setting the blending amount that has been regarded as insane in the past, and by limiting the blending amount of the heat-expandable graphite to a specific amount, while maintaining the properties indispensable for fire-resistant expansion materials, The present inventors have found that weight reduction and softening can be realized and have completed the present invention.

In the present invention, first, 100 parts by mass of urethane prepolymer,
5 to 19 parts by mass of epoxy resin,
70 to 120 parts by weight of an inorganic filler,
A fireproof joint material comprising 10 to 30 parts by mass of thermally expandable graphite is provided.
The oxygen index of the joint material for fire protection according to the present invention is not particularly limited as long as flame retardancy and shape retention are maintained, but as a preferable index, it is desirable that the enzyme index is 40 or more in the present invention. .
If the said epoxy resin is mix | blended with the said compounding quantity, the property will not be specifically limited, but when a dispersibility is considered, adding as an epoxy resin emulsion is preferable.
If the said inorganic filler is mix | blended by the said compounding quantity, the kind will not be specifically limited, In this invention, it is preferable to use aluminum hydroxide as an inorganic filler.

  The joint material for fire protection according to the present invention is lightweight and soft while maintaining properties such as flame retardancy, shape retention, moderate thermal expansion, and high temperature durability, which are indispensable for conventional fire expansion materials. Realized a significant improvement. As a result, it is possible to achieve a significant improvement in workability and contribute to a significant reduction in construction cost and construction time.

  Hereinafter, preferred embodiments for carrying out the present invention will be described. In addition, embodiment described below shows an example of typical embodiment of this invention, and, thereby, the range of this invention is not interpreted narrowly.

  The joint material for fire protection according to the present invention is roughly divided into (1) urethane prepolymer, (2) epoxy resin, (3) inorganic filler, and (4) thermally expandable graphite. Hereinafter, each component will be described in detail.

(1) Urethane prepolymer The fireproof joint material according to the present invention uses a urethane prepolymer as a main component having heat insulation. The urethane prepolymer can be prepared by condensation polymerization of isocyanates and polyhydric alcohols. The urethane prepolymer that can be used for the fireproof joint material according to the present invention is not particularly limited as long as the object of the present invention is not impaired, and one or two or more known ones may be used in combination. Is possible. For example, one-component type, two-component type, or the like obtained from any raw material can be used, but in the present invention, the one-component type is particularly preferable.

  More specifically, as isocyanates constituting the urethane prepolymer that can be used for the fireproof joint material according to the present invention, for example, 1,4-phenylene diisocyanate, 2,4- or 2,6-toluene diisocyanate (TDI), diphenylmethane-2,4′- or 4,4′-diisocyanate (MDI), naphthalene-1,5-diisocyanate, 3,3′-dimethyldiphenylmethane-4,4′-diisocyanate, crude TDI, polyphenyl One or more methane polyisocyanates (crude MDI) can be used in any combination.

  Examples of the polyhydric alcohol constituting the urethane prepolymer that can be used for the fireproof joint material according to the present invention include, for example, a polyoxyalkylene polyol obtained by adding an alkylene oxide to a low molecular weight polyol, a polyester polyol, a polyolefin polyol, an acrylic polyol, One or more polymer polyols can be used in any combination.

  In the present invention, a urethane prepolymer obtained from a urethane prepolymer having toluene diisocyanate (TDI) as a terminal group and polyethylene oxide and polypropylene oxide as a hydrophilic group can be preferably used.

(2) Epoxy resin The fireproof joint material according to the present invention uses an epoxy resin as a shape stabilizer for preventing deformation. The kind of epoxy resin that can be used for the fireproof joint material according to the present invention is not particularly limited as long as the object of the present invention is not impaired, and one or two or more known ones can be freely selected and used. Can do. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyfunctional epoxy resin, glycidyl ester type epoxy resin, biphenyl type epoxy resin and the like can be mentioned. Among these, in the present invention, bisphenol A type epoxy resin is particularly preferable in terms of excellent versatility.

  The content of the epoxy resin in the joint material for fire prevention according to the present invention is set to 5 to 19 parts by mass with respect to 100 parts by mass of the urethane prepolymer. This content has been considered to be an amount that is too small in conventional common sense, and is an amount that does not sufficiently exhibit shape retention. However, in the present invention, the inorganic filler and the thermally expandable graphite described later are limited to a specific blending amount, so that the shape retainability is maintained even when the amount is 5 to 19 parts by mass, which is extremely small compared to the conventional one. Succeeded in doing.

  The reason why it is set to 5 parts by mass or more is that it is the minimum amount in order to maintain shape retention. The reason why it is set to 19 parts by mass or less is that if it exceeds 19 parts by mass, the hardness of the obtained fireproof joint material may increase, leading to a decrease in compressibility.

  The properties of the epoxy resin are not particularly limited as long as the epoxy resin is blended in the above-mentioned blending amount. However, in the present invention, the epoxy resin is preferably added as an emulsion or powder. This is for uniformly dispersing in the urethane prepolymer. In consideration of workability, it is more preferable to add it as an epoxy resin emulsion.

(3) Inorganic filler In the fireproof joint material according to the present invention, an inorganic filler is used in order to further improve the flame retardancy of the fireproof joint material. The kind of the inorganic filler that can be used in the fireproof joint material according to the present invention is not particularly limited as long as the object of the present invention is not impaired, and one or more known ones can be freely selected and used. be able to. For example, silica, diatomaceous earth, alumina, zinc oxide, titanium oxide, magnesium oxide, iron oxide, magnesium hydroxide, aluminum hydroxide, zinc borate, sodium borate, calcium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, hydrotal Site, calcium sulfate, barium sulfate, calcium silicate, talc, clay, mica, bentonite, activated clay, sepiolite, glass fiber, glass beads, aluminum nitride, boron nitride, carbon black, graphite, and the like. Among these, in the present invention, aluminum hydroxide and magnesium hydroxide are preferable, and among these, aluminum hydroxide is more preferable. This is because an endothermic reaction occurs due to water generated by the dehydration reaction during heating, and the temperature rise of the fireproof joint material according to the present invention is suppressed.

  The content of the inorganic filler in the joint material for fire prevention according to the present invention is set to 70 to 120 parts by mass with respect to 100 parts by mass of the urethane prepolymer. This content has been considered to be an excessively large amount according to conventional common sense, and an amount in which the hardness is excessively increased. However, in the present invention, the epoxy resin and the heat-expandable graphite described later are limited to a specific blending amount. Succeeded in raising sex.

  When the amount is set to 70 parts by mass or more, the flame retardance is reduced when the amount is less than 70 parts by mass (for example, the oxygen index is less than 40), and the strength of the thermal expansion layer may be insufficient. Because. The reason why the amount is set to 120 parts by mass or less is that if the amount exceeds 120 parts by mass, the hardness of the obtained fireproof joint material may increase too much and the flexibility may decrease. This is because it may be difficult to realize the structure, and workability may be reduced.

  The inorganic filler is not particularly limited in its properties as long as it is blended in the above-mentioned blending amount. In the present invention, from the viewpoint of dispersibility, the average particle size of the inorganic filler is a measured value in the laser diffraction method. 1 to 50 μm is preferable.

(4) Thermally expandable graphite For the fireproof joint material according to the present invention, thermally expandable graphite is used in order to impart appropriate thermal expandability to the fireproof joint material. When this thermally expandable graphite is exposed to a temperature of about 200 ° C. or more, it expands by a factor of 100 or more, and exhibits a function of closing the gap and preventing the inflow of flame and smoke.

  The heat-expandable graphite that can be used for the fireproof joint material according to the present invention is not particularly limited as long as the object of the present invention is not impaired, and one or more known ones can be freely selected and used. Can do. For example, a powder such as natural graphite or pyrolytic graphite is treated with an inorganic acid such as sulfuric acid or nitric acid and a strong oxidizing agent such as concentrated nitric acid or permanganate, and a crystalline compound that maintains a graphite layered structure is used. be able to. There are various types of powders such as natural graphite and pyrolytic graphite that have been subjected to deoxidation treatment and neutralization treatment, and any of them may be used in the present invention.

  The content of the thermally expandable graphite in the fireproof joint material according to the present invention is set to 10 to 30 parts by mass, more preferably 13 to 20 parts by mass with respect to 100 parts by mass of the urethane prepolymer. By setting this content, together with the epoxy resin and the inorganic filler set to the content, conventionally, such as flame retardancy, shape retention, moderate thermal expansion, high temperature durability, etc. While maintaining the indispensable properties of the expansion material for fire prevention, we succeeded in reducing the weight and softening and increasing the compression ratio.

  The reason why it is set to 10 parts by mass or more is that if it is less than 10 parts by mass, sufficient thermal expansibility cannot be obtained and sufficient flame retardancy may not be obtained. When set to 30 parts by mass or less, when it exceeds 30 parts by mass, the thermal expansion ratio increases, but the hardness of the obtained fireproof joint material may increase too much, and the flexibility may decrease. Moreover, when specific gravity rises, it becomes difficult to implement | achieve weight reduction, and workability | operativity may fall.

  As long as the heat-expandable graphite is blended in the above-mentioned blending amount, its properties are not particularly limited, but in the present invention, the particle size of the heat-expandable graphite is about 20 to 400 mesh (measured according to JIS Z 8901). It is preferable that When the particle size is smaller than 400 mesh, the expansion coefficient of the thermally expandable graphite is small, and the obtained fireproof joint material may not be sufficiently thermally expanded at the time of fire, and when the particle size is larger than 20 mesh, the dispersibility is deteriorated and the fireproofing. This is because the elasticity of the joint material may be lowered.

  The fireproof joint material according to the present invention can achieve the object of the present invention as long as the above-described constituent components are blended in a specific content, but as one index, an oxygen index (measured according to JIS K7201). ) Is preferably 40 or more. If it is less than 40, sufficient flame retardancy may not be obtained in the event of a fire, and the shape-preventing property may be inferior. This oxygen index can be adjusted by manipulating the blending amounts of the inorganic filler and the expandable graphite.

  Moreover, it is preferable that the thermal expansion magnification in 300 degreeC and 0.5 hour of the fireproof joint material which concerns on this invention is 1.5 to 2.5 times. This is because if the thermal expansion ratio is less than 1.5 times, it does not expand sufficiently in the event of a fire, the target gap or the like cannot be sufficiently blocked, and fire spread may not be prevented. . The reason why the thermal expansion ratio is set to 2.5 times or less is that the fireproof joint material according to the present invention has flexibility, so that it can be compressed and inserted into the fireproofing portion. 100-compression ratio) multiplied by this thermal expansion ratio is the expansion ratio in the construction state, but if the thermal expansion ratio is 2.5 times, it is sufficient as an effect to prevent the spread of fire in an actual fire site. Because there is.

  Moreover, it is preferable that the specific gravity of the fireproof joint material which concerns on this invention is 0.22 or less. This is to reduce the weight of the fireproof joint material according to the present invention and to improve the workability.

  Further, the hardness of the fireproof joint material according to the present invention is preferably 8 or less. This is because the joint material for fire protection according to the present invention is softened and the workability is improved.

  Furthermore, it is preferable that the compression rate of the fireproof joint material according to the present invention is 65% or more. This is because the workability of the fireproof joint material according to the present invention is improved.

  The joint material for fire prevention according to the present invention described above is characterized by its constituent components and blending ratio, and its production method is not particularly limited, and can be produced by freely selecting a known method. For example, first, a slurry is prepared using thermally expandable graphite, an epoxy resin, and an inorganic filler. At this time, it is possible to prevent the epoxy resin from adhering to the inner wall of the kneading apparatus by adding water and mixing in a liquid state. Next, a urethane prepolymer is added to the slurry, and stirring and mixing is continued until foaming starts, and then the slurry is poured into a mold having a predetermined shape and subjected to foam molding. Furthermore, the joint material for fire prevention according to the present invention can be manufactured by curing at a predetermined temperature (for example, about 50 ° C.) and evaporating the contained water. In addition, what is necessary is just to set a curing time suitably according to the magnitude | size and curing temperature of the foaming molding which is a joint material for fire prevention.

  Although the solid content in the slurry in the production process can be appropriately set according to the intended use and application of the final product, it is usually 15 to 80% by mass, particularly preferably 30 to 60% by mass. When the solid content is less than 15% by mass, the shape stability of the resulting molded product may be reduced. When the solid content exceeds 80% by mass, the viscosity of the slurry increases, and a desired fireproof joint is obtained. This is because the material may not be obtained.

  In addition, other additives may be blended in the slurry in the production process as necessary. For example, surfactants, crosslinking agents, foam stabilizers, catalysts, foaming agents, flame retardants, stabilizers, ultraviolet absorbers, antioxidants, pigments, fillers, and the like can be added. These additives can be mixed with the heat-expandable graphite, epoxy resin, and inorganic filler simultaneously or sequentially, and then uniformly mixed with a known stirrer or the like to adjust the slurry containing the additive.

  The joint material for fire prevention according to the present invention can be applied to any known construction method using a fireproof inflatable material. The use method and use site in each method are not particularly limited, and can be widely used in places where fire resistance is required.

  For example, it can be used to close a part or all of the gaps of the through holes provided in the fireproof compartment. Moreover, it is suitably used also for the fire-proofing part of the joint, for example, in the case of building a structure assembled in advance in a factory as in the unit construction method. Specifically, a power cable or communication cable passing through a through-hole provided in a fire barrier such as a fire wall or a floor slab, a gap between the pipe and the fire wall is covered with the fire joint material according to the present invention, The fireproof joint material according to the present invention can be used by mounting a gasket produced by molding the fireproof joint material into a shape suitable for the construction part.

  Furthermore, the joint material for fire protection according to the present invention formed in a tape shape may be attached to the joint of the exterior material of a unit type apartment house or building and used by compressing and adhering. In addition, it can be used between an apparatus main body requiring fire prevention and a fireproof panel covering it, or at an end of the fireproof panel. In this case, it is possible to use by sticking with an adhesive or an adhesive, or fixing with bolts or nails.

  The joint material for fire protection according to the present invention has various properties such as lightness, softness, compressibility, heat insulation, shape retention, high temperature durability, elasticity, flexibility, and thermal expansion. Therefore, it can be widely used in various fields that require characteristics such as elasticity, flexibility, thermal expansion, heat insulation, fire resistance, vibration damping, and soundproofing.

  Hereinafter, the present invention will be described in more detail based on examples. In addition, the Example demonstrated below shows an example of the typical Example of this invention, and, thereby, the range of this invention is not interpreted narrowly.

“Part” and “%” in this example are based on mass. Details of the materials used in this example are shown below.
(1) Polyol urethane prepolymer: “EGH-401” manufactured by Mitsui Chemicals Polyurethanes Co., Ltd.
(2) Epoxy resin: bisphenol A type epoxy resin emulsion (Japan Epoxy Resin Co., Ltd., “W2811R70” solid content 70%), bisphenol F type epoxy resin powder (Japan Epoxy Resin Co., Ltd., “4010P”)
(3) Thermally expandable graphite: “SS-3” manufactured by Air Water, Inc., expansion start temperature 260 ° C.
(4) Inorganic filler: Aluminum hydroxide (Nippon Light Metal Co., Ltd., “B53”)

<Production of fireproof joint material>
According to the blending amounts shown in Table 1 and Table 2 below, water was added to a mixture of epoxy resin, thermally expandable graphite, and inorganic filler to prepare a slurry. A urethane prepolymer was added to the slurry, mixed with stirring, poured into a 12 cm × 12 cm × 17 cm mold, foamed, cured with an oven at 100 ° C. for 1 hour, and then demolded. The obtained foamed cured product was further cured in an oven at 50 ° C. for 2 days to evaporate water, thereby producing sponge-like fireproof joint materials (Examples 1 to 9, Comparative Examples 1 to 6).

<Evaluation of each characteristic>
About the fireproof joint material which concerns on Examples 1-9 and Comparative Examples 1-6, according to the following measuring method, each characteristic was evaluated. The evaluation results are shown in Tables 1 and 2.

(1) Specific gravity The specific gravity was measured with an electronic hydrometer (manufactured by Mirage Trading; EW120SG) according to JIS K6220.
(2) Hardness The hardness was measured by reading the instruction of the hardness meter immediately after applying a C-type rubber hardness meter (manufactured by Kobunshi Keiki Co., Ltd.) to the foamed molded product.
(3) Compressibility The 50 mm square foamed molded product was compressed with a compression tester at a compression rate of 10 mm / min. The compressibility when the compressive stress was 0.1 MPa was measured.
(4) Thermal expansion ratio The expansion ratio after the test piece was left in an atmosphere maintained at 300 ° C for 0.5 hours was measured.
(5) Shape retention The test piece after measuring the thermal expansion magnification was evaluated by visual observation and finger touch. Those that did not lose shape and did not collapse even when touched with a finger were evaluated as “good”, and those that immediately collapsed with a finger touch or that had already collapsed were evaluated as “impossible”.
(6) Oxygen index It measured using the combustibility test apparatus (the Suga Test Instruments Co., Ltd. ON-1D type | mold) according to JISK6269.

  As shown in Table 1, all of the fireproof joint materials according to Examples 1 to 9 have low specific gravity and hardness (specific gravity: 0.22 or less, hardness while maintaining good shape retention and an oxygen index of 40 or more. : 8 or less), it was found that the compression rate was high (compression rate: 65 or more). Moreover, the thermal expansion magnification of the fireproof joint material according to Examples 1 to 9 is not too high or too low (1.5 to 2.5 times), and sufficiently exhibits the fire spread prevention effect in an actual fire site. It was suggested.

  On the other hand, as shown in Table 2, it was found that each comparative example did not achieve the object of the present invention in the following points.

(1) Comparative Example 1
The joint material for fire prevention according to Comparative Example 1 had a low specific gravity and hardness, a high compression rate, and a good shape retention, but the expansion ratio and the oxygen index were low because the amount of expansive graphite was small. I understood that. Therefore, the joint material for fire prevention according to Comparative Example 1 has a low expansion ratio, so the fire spread prevention effect at the fire site is inferior, and since the oxygen index is low, it is considered that sufficient flame retardancy cannot be obtained at the time of fire. It is done.

(2) Comparative Example 2
The joint material for fire protection according to Comparative Example 2 has good shape retention and an oxygen index of 40 or more, and thus is considered to have good flame retardancy. Therefore, it was found that the specific gravity and the hardness were high, and the compression ratio was lowered accordingly. Moreover, since the compounding quantity of expansive graphite was large, it turned out that an expansion ratio becomes high too much. Therefore, the joint material for fire protection according to Comparative Example 2 is considered to have poor workability because of its high specific gravity and hardness and low compression rate.

(3) Comparative Example 3
The fireproof joint material according to Comparative Example 3 has a low specific gravity and hardness, a high compression ratio, an appropriate expansion ratio, and an oxygen index of 40 or more, but the shape of the epoxy resin is too low. It was found that the retention was inferior.

(4) Comparative Example 4
The joint material for fire prevention according to Comparative Example 4 has an oxygen index of 40 or more, so it is considered that the flame retardancy is good, but the amount of the epoxy resin is extremely small so as to fall within the scope of the present invention. Nevertheless, it was found that the specific gravity and hardness are high due to the large amount of thermally expandable graphite, and accordingly, the compression ratio is low and the shape retention is also poor. Moreover, since the compounding quantity of expansive graphite was large, it turned out that an expansion ratio becomes high too much. Therefore, the joint material for fire prevention according to Comparative Example 4 is considered to have poor workability because of its high specific gravity and hardness and low compression rate.

(5) Comparative Example 5
The joint material for fire prevention according to Comparative Example 5 had a low specific gravity and hardness, a high compression ratio, an appropriate expansion ratio, and good shape retention, but because the blending amount of the inorganic filler was small, the oxygen index was low. Was found to be lower. Therefore, since the joint material for fire prevention according to Comparative Example 5 has a low oxygen index, it is considered that sufficient flame retardancy cannot be obtained in a fire and the strength of the thermally expandable layer is insufficient.

(6) Comparative Example 6
The fireproof joint material according to Comparative Example 6 had an appropriate thermal expansion ratio, good shape retention, and an oxygen index of 40 or more. However, since the amount of the inorganic filler was too large, the specific gravity and hardness were too high. It was found that the compression ratio increased with the increase. Therefore, the joint material for fire prevention according to Comparative Example 6 is considered to have poor workability because of its high specific gravity and hardness and low compression rate.

  As a result of this example, while maintaining the properties required for conventional fireproof joint materials such as shape retention, flame retardancy, and moderate thermal expansion, weight reduction, softening, and increase in compression rate are achieved. In order to achieve this, the blending amount of the epoxy resin and the inorganic filler, the blending amount that has been regarded as insane in the past to impart shape stabilization performance and workability (epoxy resin: 5 to 19 parts by mass, inorganic) It was found that it was necessary to dare to set the filler: 70 to 120 parts by mass) and to limit the blending amount of the thermally expandable graphite to a specific amount such as 10 to 30 parts by mass.

Claims (4)

100 parts by mass of urethane prepolymer,
5 to 19 parts by mass of epoxy resin,
70 to 120 parts by weight of an inorganic filler,
A fireproof joint material comprising 10 to 30 parts by mass of thermally expandable graphite.   The joint material for fire prevention according to claim 1, wherein the oxygen index is 40 or more.   The fireproof joint material according to claim 1 or 2, wherein the epoxy resin is added as an epoxy resin emulsion.   The fireproof joint material according to any one of claims 1 to 3, wherein the inorganic filler is aluminum hydroxide.