JP2006257181A - Joint sealer for fire prevention - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joint sealer for fire prevention, having good application operability and durability, and also having excellent flexibility and fire-preventing property. <P>SOLUTION: The joint sealer for the fire prevention having flame retardancy of ≥40 oxygen index is obtained by adding a specific amount of a thermally expandable graphite, aluminum phosphite and an inorganic filler to a flexible polyurethane foam comprising an aqueous urethane prepolymer. The joint sealer is thermally expanded when fire breaks out to prevent the flame from flowing in from a gap, and provides a residue after burning, having sufficient shape-retaining characteristics. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fireproof joint material used for a gap between building fireproof compartments.

  An expansion material for fire prevention has been used as a joint material between cables such as power cables and communication cables penetrating a fire prevention compartment of a building, piping such as air conditioning equipment, and a fire barrier. 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. For this reason, in the fireproof joint material made of the fireproof expansion material, it is required that the expansion layer is not easily deformed by the flame heat and can maintain a predetermined shape as long as possible, especially after the formation of the expansion layer.

  Since the expansion layer for fire protection does not cause the expansion layer to be deformed by flame heat and it is necessary to maintain a predetermined shape for a long time, the shape of the base resin is stabilized with an inorganic expansion agent and / or an organic expansion agent. 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 resin for use has been proposed (for example, see Patent Document 1). However, depending on the application, the elasticity and flexibility were not sufficient and the workability was poor.

  As a fireproof expansion material having excellent elasticity and flexibility, a process for producing polyurethane imparted with fire resistance is also known (see, for example, Patent Document 2). This is characterized in that expansive graphite is blended in the polyol and polyisocyanate as a flame retardant and powdered casein is used as a shape stabilizer, but the shape stabilization is not sufficient. Furthermore, 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, and sufficient fire resistance performance cannot be obtained.

  Further, a flexible fireproof rubber joint material made of rubber, expandable graphite, epoxy resin and inorganic filler has been disclosed (for example, see Patent Document 3), and the brittleness and fire resistance which have been problems in the past have been improved. However, there is a problem that the epoxy resin blended for stabilizing the shape after expansion adheres to the inner wall of the kneading apparatus during kneading, and this removal is extremely difficult.

Furthermore, a composition in which boric acid is added to a flexible urethane foam blended with expansive graphite has been disclosed as an improvement in the stabilization of the shape after expansion (see, for example, Patent Document 4). When exposed, there was a problem of loss of elasticity due to hydrolysis.
JP 09-176498 A (2nd page: claims 1 to 5) Japanese Patent No. 2732435 (first page: claims 1-9, second claims 10-12) JP 2002-181262 A (page 2: claim 1) JP 2001-348476 A (2nd page: claims 1 to 8)

  The present invention is used for a gap in a fire prevention compartment of a building, a fire prevention part of a seismic isolation device, etc., and in the event of a fire, it thermally expands and closes the gap to prevent the inflow of flames and maintains a sufficient shape It is an object of the present invention to provide a joint material for fire prevention having a high temperature and durability for a long period of time.

  The present invention is a fireproof joint material comprising a flexible urethane foam obtained from an aqueous urethane prepolymer, thermally expandable graphite, aluminum phosphite, and an inorganic filler, and having an oxygen index of 40 or more. Furthermore, the present invention is based on 100 parts by mass of a flexible urethane foam obtained from an aqueous urethane prepolymer, 10 to 100 parts by mass of thermally expandable graphite, 10 to 100 parts by mass of aluminum phosphite, and 10 to 150 parts by mass of an inorganic filler. A fireproof joint material, wherein the inorganic filler is aluminum hydroxide. It is also a gasket using this fireproof joint material.

  The joint material for fire prevention of the present invention forms a non-combustible intumescent layer that is stable at the time of a fire, and even when exposed to a high temperature for a long time, the intumescent layer is not easily brittle and has excellent fire prevention performance.

  The joint material for fire prevention of the present invention contains a flexible urethane foam obtained from an aqueous urethane prepolymer, thermally expandable graphite, aluminum phosphite and an inorganic filler.

  The flexible urethane foam used in the present invention is a flexible urethane foam obtained from a one-pack type aqueous urethane prepolymer. As the aqueous urethane prepolymer, known products or commercially available products can be used.

Thermally expandable graphite is a powder of natural graphite, pyrolytic graphite, etc., treated with an inorganic acid such as sulfuric acid or nitric acid and a strong oxidizing agent such as concentrated nitric acid or permanganate. It is a maintained crystalline compound. When these are exposed to a temperature of about 200 ° C. or higher, they thermally expand 100 times or more. These natural graphite, pyrolytic graphite and other powders can be used in various types other than deoxidation treatment and further neutralization treatment.
The particle size of the thermally expandable graphite is preferably about 20 to 400 mesh. When the particle size is smaller than 400 mesh, the expansion coefficient of the heat-expandable graphite is small, and the resulting fireproof joint material may not be sufficiently thermally expanded in the event of a fire. The elasticity of joint materials may be reduced.

  The content of the heat-expandable graphite can be appropriately set depending on the type of flexible urethane foam obtained from the water-based urethane prepolymer, the desired expansion ratio, etc., but usually 10 to 100 parts per 100 parts by mass of the flexible urethane foam. The use of parts by mass is preferred, and more preferably 20 to 80 parts by mass. If the content of the heat-expandable graphite is less than 10 parts by mass, the obtained fireproof joint material may not be sufficiently thermally expanded at the time of fire, and if it exceeds 100 parts by mass, the thermal expansion ratio is increased, but the obtained fireproof There is also a tendency for physical properties such as strength of joint materials to decrease.

In the present invention, aluminum phosphite is used as a thermal expansion agent and a shape stabilizer for preventing deformation. The average particle diameter of the aluminum phosphite used in the present invention is preferably 1 to 100 μm as measured by a laser diffraction method from the viewpoint of dispersibility.

  The content of aluminum phosphite can be set as appropriate depending on the type of flexible urethane foam obtained from the aqueous urethane prepolymer, the desired expansion ratio, etc., but in 100 parts by mass of the flexible urethane foam obtained from the aqueous urethane prepolymer. The amount is preferably 10 to 100 parts by mass. When the amount is less than 10 parts by mass, the shape stabilization performance of the obtained fireproof joint material is insufficient, and when it exceeds 100 parts by weight, the hardness of the obtained fireproof joint material tends to increase and flexibility tends to decrease. .

The content of the inorganic filler can be appropriately set according to the type of flexible urethane foam obtained from the aqueous urethane prepolymer, the desired expansion ratio, etc., but with respect to 100 parts by mass of the flexible urethane foam obtained from the aqueous urethane prepolymer. 10 to 150 parts by mass is preferable. If it is used in excess of 150 parts by mass, the hardness of the foamed molded product is increased, the flexibility is inferior, and the workability may be deteriorated.

In this invention, in order to improve the flame retardance of the joint material for fire prevention more, an inorganic filler is used. Examples of the inorganic filler include silica, diatomaceous earth, alumina, zinc oxide, titanium oxide, magnesium oxide, iron oxide, magnesium hydroxide, aluminum hydroxide, zinc borate, sodium borate, calcium carbonate, magnesium carbonate, and zinc carbonate. , Barium carbonate, hydrotalcite, calcium sulfate, barium sulfate, calcium silicate, talc, clay, mica, bentonite, activated clay, sepiolite, glass fiber, glass beads, aluminum nitride, boron nitride, carbon black, graphite, etc. It is done. These may be used alone or in combination of two or more. Among these, aluminum hydroxide and magnesium hydroxide are preferable in that an increase in temperature can be suppressed by an endothermic reaction due to a dehydration reaction during heating. Of these, aluminum hydroxide is particularly preferred.
From the viewpoint of dispersibility, the average particle diameter of these fillers is preferably 1 to 50 μm as measured by a laser diffraction method.

The fireproof joint material of the present invention has an oxygen index of 40 or more. If it is less than 40, the flame retardance at the time of a fire is inadequate, and shape prevention property is also inferior. Adjustment of the oxygen index can be adjusted by the blending amounts of expansive graphite, aluminum phosphite, and inorganic filler.

The method for adjusting the joint material of the present invention is not particularly limited. First, water is added to thermally expandable graphite, aluminum phosphite, and an inorganic filler to form a slurry, and then the aqueous urethane preform is added to the slurry. It is preferable to add the polymer and continue stirring and mixing until foaming starts, and then pour into a mold having a predetermined shape to perform foam molding, and then cure at about 50 ° C. to evaporate the contained water. 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.

  The compounding ratio of the heat-expandable graphite, aluminum phosphite and inorganic filler is as described above and can be appropriately set depending on the application and purpose, but the total amount in the slurry is usually 20 to 90% by mass, preferably Is 50-70 mass%. When solid content is less than 20 mass%, there exists a possibility that the stable expansion | swelling layer at the time of a fire may not be obtained. Moreover, when it exceeds 90 mass%, the viscosity of a slurry will rise and it may become impossible to obtain the joint material for fire preventions where the performance was stabilized.

  In addition, other additives such as surfactants, crosslinking agents, foam stabilizers, catalysts, foaming agents, flame retardants, stabilizers, ultraviolet absorbers, antioxidants, pigments, fillers are added to the slurry as necessary. Etc. can also be blended. These additives are preferably mixed simultaneously or sequentially at the time of slurry adjustment, and then uniformly mixed with a known stirrer or the like.

  The joint material for fire prevention of the present invention can be used in various fields that require properties such as elasticity, flexibility, thermal expansion, thermal insulation, fire resistance, vibration damping, and soundproofing, It can also be applied to a known method using the method, and may be used according to the method of use in each method. The use site is not particularly limited, and can be used widely in places where fire resistance is required.

  In particular, the joint material for fire prevention of the present invention is suitably used for closing part or all of the gaps of the through holes provided in the fire prevention compartment. Specifically, the gap between the fire wall and the power cable, communication cable, pipe, etc. through the through-hole provided in the fire compartment such as a fire wall and floor slab is covered with the fire joint material of the present invention, or construction There is also a method in which a gasket having a shape suitable for the part is formed and attached. Moreover, it is used suitably also for the fireproof part of the seismic isolation device of a building. Specifically, it is used between the seismic isolation device main body and the fireproof panel that covers it or at the end of the fireproof panel, and can be used by sticking with adhesive or adhesive, or fixing with bolts or nails, etc. .

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, these Examples do not limit this invention. In addition, the part and% in the following description are based on a mass reference | standard.

  Slurries were prepared by adding water to a mixture of thermally expandable graphite, aluminum phosphite, and inorganic filler in the blending amounts shown in Tables 1 and 2. Aqueous urethane prepolymer was added to the slurry, mixed with stirring, poured into a mold having dimensions of 12 cm × 12 cm × 17 cm, foam-molded, cured in 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 the water, thereby obtaining a sponge-like molded product.

The materials used in the examples are as shown below.
(1) Aqueous urethane prepolymer: (Mitsui Chemicals, "EGH-401")
(2) Boric acid: (BORAX Co., Ltd.)
(3) Aluminum phosphite: (Tahei Chemical Industry Co., Ltd., “APA-100”)
(4) Thermally expandable graphite: (“SS-3” manufactured by Air Water Chemical Co., Ltd., expansion start temperature 260 ° C.)
(5) Inorganic filler: Aluminum hydroxide (Nippon Light Metal Co., Ltd., “B53”)

"Examples 1-4""Comparative Examples 1-4"
In the examples and comparative examples, the following characteristics were evaluated and summarized in Tables 1 and 2.
The measuring method of each characteristic is shown below.
Slurry state: The state of the slurry of thermal expansion agent, aluminum phosphite, inorganic filler and water was investigated, and the flowable state was evaluated as “good”, and the non-flowable state was evaluated as “impossible”.
Surface hardness: 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.
Expansion ratio: The expansion ratio after the foamed molded product was left in an atmosphere maintained at 300 ° C. for 0.5 hours was measured.
Shape retention: The foamed molded body was allowed to expand in an atmosphere maintained at 300 ° C. for 0.5 hour, and then the hardness of the expanded body was examined by finger touch. “Excellent” if the expansion body is hard and firm, “Good” if the shape can be maintained, “Yes” if the shape is maintained somehow, No shape retention or melting “Not possible”.
Oxygen index: Measured according to JIS K7201 using a flammability test apparatus (manufactured by Suga Test Instruments Co., Ltd., ON-1D type).
Durability: A test piece of 5 cm square was cut out from the foamed molded article, heat-treated in a gear oven at 100 ° C. for 5 days, and then left at room temperature for 1 day to observe the hydrolysis state of the sponge.
“Fair” indicates that there is no change in elasticity due to finger touch, and “impossible” indicates that hydrolysis has occurred and elasticity has been lost.

Claims (4)

  A joint material for fire prevention, comprising a flexible urethane foam obtained from an aqueous urethane prepolymer, thermally expandable graphite, aluminum phosphite and an inorganic filler, and having an oxygen index of 40 or more.   The soft urethane foam obtained from the aqueous urethane prepolymer is 100 parts by mass, the thermally expandable graphite is 10 to 100 parts by mass, the aluminum phosphite is 10 to 100 parts, and the inorganic filler is 10 to 150 parts by mass. The joint material for fire prevention described. The fireproof joint material according to claim 1 or 2, wherein the inorganic filler is aluminum hydroxide. The gasket which consists of the joint material for fire prevention as described in any one of Claims 1-3.