JP2006087819A - Fireproof joint materials and gaskets - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joint filling material for fire prevention used for filling a gap between structures in fireproof panel covering a seismic isolator with a laminated base-isolating rubber, which has satisfactory mounting workability and durability and excellent flexibility and fire resistant properties. <P>SOLUTION: The joint filling material for fire prevention has flame retardant properties, thermally expands when a fire occurs, and the residue after burning has sufficient shape retainability and flexibility, by adding and mixing an expansive graphite, boric acid, and an inorganic filler into a rubber component containing a specific amount of a thermoplastic elastomer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fireproof joint material and a gasket using the fireproof joint material.

  In high-rise buildings, seismic isolation laminated rubber composed of steel plates and rubber sheets stacked alternately, and seismic isolation devices consisting of seismic isolation laminated rubber bearings are installed between the upper structure and lower structure of the building. May be. Even if the seismic isolation device is covered with fire-resistant panels so that it will not burn out in a fire, there may be some gaps in order to exert the seismic isolation effect when an earthquake occurs. There was a risk that a flame could intrude through the gap, causing the seismic isolation device to burn out.

  In order to solve this problem, it is conceivable to use a thermally expandable joint material that does not allow the flame to enter the seismic isolation device after it expands itself by heat from the fire and closes the gap.

  For example, as such a thermally expandable joint material, a flexible fire joint material for fire prevention made of rubber, expandable graphite, epoxy resin, and inorganic filler is disclosed (for example, see Patent Document 1). However, the epoxy resin blended to hold the expandable graphite under high temperature adheres to the inner wall of the kneading machine when blending and kneading the joint material, and this removal is extremely difficult and workability is poor. The shape retention was not always sufficient.

Although a composition similar to the composition of the present invention has been disclosed (see Patent Document 2), it could not be said to be suitable for the use of the present invention. On the other hand, as a seismic isolation device application, a method of covering the entire device with a thermally expandable fireproof sheet made of a resin composition containing thermally expandable graphite and an inorganic filler (see, for example, Patent Document 3) has been proposed. However, in the event of a fire, the fireproof sheet could fall and peel off from the mounting part.
JP 2002-181262 A (page 2: claim 1) JP 2001-348487 A (2nd page: claims 1 to 4) JP 2003-176638 A (2nd page: claims 1 to 9)

  It is an object of the present invention to provide a fireproof joint material excellent in strength, punchability, flexibility, and shape retention.

The present invention is a fireproof joint comprising 100 parts by mass of a rubber component containing 20% by mass or more of a thermoplastic elastomer, 5 to 100 parts by mass of expansive graphite, 10 to 100 parts by mass of boric acid, and 10 to 300 parts by mass of an inorganic filler. It is a material.
A preferred thermoplastic elastomer is a block copolymer composed of a block polymer mainly composed of vinyl aromatic hydrocarbon monomer and a block polymer mainly composed of conjugated diene monomer, and further contains boric acid and inorganic filler. The preferred mass ratio with the material is 1: 5 to 10: 1 and the preferred inorganic filler is aluminum hydroxide.
Further, the present invention is a gasket using the fireproof joint material, and a fireproof joint material for a seismic isolation device using the fireproof joint material.

  The fireproof joint material and gasket of the present invention have sufficient flexibility, and thermally expand in the event of a fire, and the residue has sufficient shape retention.

  Examples of the rubber component used in the present invention include ethylene propylene rubber, butyl rubber, styrene butadiene rubber, isoprene rubber, acrylonitrile butadiene rubber, polybutadiene rubber, chloroprene rubber, polybutene rubber, chlorinated polyethylene rubber, acrylic rubber, chlorosulfonated polyethylene, Silicone rubber, fluorine rubber, and natural rubber can be used.

  These rubber components may be used in a blend of two or more in order to improve kneading properties, sheet formability, extrusion moldability, press formability, and the like.

Examples of the thermoplastic elastomer used in the present invention include a vinyl chloride elastomer, a styrene elastomer, a polyolefin elastomer, and a polyester elastomer, and a styrene elastomer is particularly preferable. Even a styrene-based elastomer is more preferably a block copolymer composed of a block polymer mainly composed of a vinyl aromatic hydrocarbon monomer and a block polymer mainly composed of a conjugated diene monomer. It is preferable that at least 20% by mass of such a thermoplastic elastomer is contained in the rubber component, and more preferably 20% by mass to 70% by mass.

A block copolymer comprising a block polymer mainly composed of a vinyl aromatic hydrocarbon monomer and a block polymer mainly composed of a conjugated diene monomer is 1) mainly composed of an aromatic hydrocarbon monomer. The block polymer part melts by heat in the event of a fire and plays a role of temporarily holding the thermally expanded expansive graphite. 2) The block polymer part mainly composed of aromatic hydrocarbon monomers is melted. 3) Block polymer part mainly composed of aromatic hydrocarbon monomer improves the dimensional stability of the molded product, and 4) mainly composed of conjugated diene monomer. When the block polymer portion exhibits rubber elasticity at room temperature and exhibits strength and flexibility, the balance between strength and flexibility when mounting a fireproof joint material or gasket is improved.

As a vinyl aromatic hydrocarbon monomer used in a block copolymer consisting of a block polymer mainly composed of vinyl aromatic hydrocarbon monomers and a block polymer mainly composed of conjugated diene monomers, Examples thereof include styrene, p-methylstyrene, α-methylstyrene, vinyl xylene, monochlorostyrene, dichlorostyrene, monobromostyrene, and the like, and these are used alone or in combination of two or more. Of these, styrene is particularly preferred.
Examples of the conjugated diene monomer include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and the like. These may be used alone or in combination of two or more. The Of these, preferred is 1,3-butadiene or isoprene, and particularly preferred is 1,3-butadiene.

  20 / 80-60 / 40 mass% of the ratio of the vinyl aromatic hydrocarbon monomer and the conjugated diene monomer of the styrene elastomer is preferable, and 25 / 75-40 / 60 mass% is more preferable. If the vinyl aromatic hydrocarbon monomer is less than 20% by mass, the formability of the fireproof joint material is lowered, and if it exceeds 60% by mass, the flexibility tends to be lowered.

  The styrenic elastomer used in the present invention is produced by known anionic polymerization.

  The expandable graphite is not particularly limited. Expandable graphite is a crystalline compound in which powder of natural graphite, pyrolytic graphite or the like 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 maintains a graphite layered structure. When exposed to a temperature of about ℃ or higher, it expands by a factor of 100 or more. In addition, there are various types of expansive graphite, such as a type in which the powder is deoxidized and then neutralized, and any of them can be used. The particle size is preferably 20 to 400 mesh. Even when the same mass is blended, the thermal expansion of the fireproof joint material decreases when the particle size becomes smaller than 400 mesh, and when the particle size becomes larger than 20 mesh, the dispersibility deteriorates and the tensile stress of the fireproof joint material decreases. Sometimes.

  The content of the expandable graphite can be appropriately set depending on the desired expansion ratio and the like, but is preferably 5 to 100 parts by mass, more preferably 20 to 80 parts by mass with respect to 100 parts by mass of the rubber component. If the amount is less than 5 parts by mass, the thermal expansion ratio of the fireproof joint material in the event of a fire is small, and if it exceeds 100 parts by mass, the thermal expansion ratio increases, but the hardness of the resulting fireproof joint material increases and the tensile stress is increased. There is a tendency to decrease. In addition, the formability of the sheet is inferior, and the surface skin is likely to deteriorate when formed into a gasket.

As boric acid, a product obtained by a known production method or a commercially available product can be used. The boric acid may be any of orthoboric acid (H ₃ BO ₃ ), metaboric acid (HBO ₂ ), etc., but orthoboric acid is usually used.

  Boric acid is usually used in powder form. In this case, the particle size of the powder is not particularly limited, but the average particle size is preferably 100 μm or less, and more preferably 20 μm or less, from the flexibility required for the fireproof joint material. The average particle diameter is obtained by a laser diffraction method.

  The content of boric acid can be appropriately set depending on the amount of expansive graphite used, but is preferably 10 to 100 parts by mass, more preferably 30 to 90 parts by mass with respect to 100 parts by mass of the rubber component. When the amount is less than 10 parts by mass, the effect of holding the expandable graphite is small, and there is a fear that the shape retention property showing the performance of maintaining the shape after expansion in a fire may be inferior. Moreover, when it exceeds 100 mass parts, the hardness of the fireproof joint material will become high and flexibility will be inferior, and there exists a possibility that workability | operativity may fall at the time of mounting | wearing operation | work of the fireproof joint material and its gasket.

  The ratio of boric acid to expandable graphite is preferably 1: 5 to 10: 1, more preferably 1: 2 to 5: 1 by mass ratio. If it is within this range, the balance of workability at the time of manufacturing a fireproof joint material, punchability when punching a gasket product from a sheet-like molded product, flexibility, tensile stress, etc. will be good.

  Examples of inorganic fillers include silica, diatomaceous earth, alumina, zinc oxide, titanium oxide, magnesium oxide, iron oxide, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, 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, carbon fiber, etc., these are sheet processability And improve punchability when manufacturing gaskets. Two or more of these may be used in combination. The average particle size is preferably 1 to 50 μm from the viewpoint of dispersibility in rubber.

  Among the inorganic fillers, aluminum hydroxide is preferable as a fireproof joint material in that heat is generated due to water generated by a dehydration reaction during heating, and temperature rise is suppressed.

  The inorganic filler is preferably used in an amount of 10 to 300 parts by mass based on 100 parts by mass of the rubber component. If the amount is less than 10 parts by mass, the effect of improving the sheet formability and punchability is small. If the amount exceeds 300 parts by mass, the hardness of the fireproof joint material increases, and the use of a gasket formed by processing the sheet and the possibility of molding the same is possible. Flexibility is inferior, and there is a risk that workability may be deteriorated during mounting work of a fireproof joint material or a gasket made thereof.

  In order to mix and knead the thermoplastic elastomer, expandable graphite, boric acid, and inorganic filler with the rubber component, a known kneading apparatus such as a Banbury mixer, a kneader mixer, or a two-roller can be used. Further, the kneaded product can be processed into a rubber sheet by a conventionally known molding method such as press molding, roll molding, extrusion molding, calendar molding, or the like. From this sheet, a fireproof joint material or gasket can be obtained by punching into a string shape or a ring shape using a known device having a punching blade.

  Furthermore, plasticizers, softeners, anti-aging agents, processing aids, lubricants, tackifiers, vulcanizing agents and the like generally used for rubber components can be used in combination as appropriate.

  Fireproof joint materials and gaskets can be used in various fields because of their properties such as elasticity, flexibility, thermal expansion, thermal insulation, fire resistance, vibration control, and soundproofing, but are known to use inflatable fireproof materials. It can also be applied to construction methods and may be used according to the method of use in each construction method.

  The joint material for fire prevention and the gasket are particularly preferably used for a fire prevention part of a seismic isolation device for a building. Specifically, the fireproof joint material and gasket of the present invention can be attached to the end portion of the fireproof panel covering the seismic isolation device with an adhesive or adhesive, or can be fixed with bolts or nails.

EXAMPLES The present invention will be specifically described below with reference to examples, but these examples do not limit the present invention. In addition, the part and% in the following description are based on a mass reference | standard.
"Examples 1-3""Comparative Examples 1-5"

In the examples and comparative examples, the materials used are as follows.
(1) Rubber component: butyl rubber (manufactured by JSR Corporation, “butyl 268”), ethylene-propylene-diene rubber (manufactured by DSM Japan Co., Ltd., “Keltan 2630A”), SBS (JSR Shell Co., Ltd., Kraton D1101) Vinyl aromatic hydrocarbon monomer / conjugated diene monomer = 30/70).
(2) Thermally expandable graphite: (“SS-3” manufactured by Air Water Chemical Co., Ltd., expansion start temperature 260 ° C.)
(3) Boric acid: (BORAX Co., Ltd.)
(4) Inorganic filler: Aluminum hydroxide (Showa Denko Co., Ltd., “Hijilite H-42”)
(5) Softener: Naphthenic oil (“NP-24” manufactured by Idemitsu Kosan Co., Ltd.)
(6) Processing aid: glycerin fatty acid ester (“Emaster 510P” manufactured by Riken Vitamin Co., Ltd.).

  Each component was kneaded with a 3 liter kneader and formed into a sheet with a thickness of 5 mm with two rolls. From a hot sheet at 80 to 100 ° C., a JIS No. 3 dumbbell for measuring tensile stress, a JIS No. 1 dumbbell for evaluating flexibility, and a 5 mm thick × 50 mm wide × 70 mm long test as a thermal expansion test piece Each piece was punched with a punching blade and immediately immersed in water for 10 seconds and cooled. Thereafter, it was taken out, air-dried, and further dried in a gear oven at 50 ° C. for about 3 hours.

  Tensile stress, hardness, punchability, flexibility, thermal expansibility, shape retention, and oxygen index were evaluated using the above test pieces as follows.

  Tensile stress: Tensile stress was determined with a JIS No. 3 dumbbell at a speed of 500 mm / min to obtain the maximum stress.

  Hardness: A test piece for evaluation for thermal expansion was used to read the value immediately after pressing using a durometer A hardness meter.

  Punchability: When punching a JIS No. 3 dumbbell, the surface condition of the punched portion was evaluated as good (good), and the rough surface was evaluated as x (bad).

  Flexibility: When one end of JIS No. 1 dumbbell is fixed and the other end is bent to an angle of 45 degrees, the degree of cracking at the bent portion is indicated as ○ (good) when there is no crack, and × when there is a crack. It was evaluated as (evil).

  Thermal expansion: Inserted and installed so that the lower 50 mm of the thermal expansion test piece is buried and the upper 20 mm protrudes between the 10 mm gaps between the refractory bricks and the refractory bricks. Heat treated for hours. When the gap of 10 mm was completely closed, it was evaluated as ◯ (good), and otherwise it was evaluated as x (bad).

  Shape retention: After completion of the thermal expansion test, the shape stability and deformation degree of the upper 20 mm portion of the test piece were evaluated by finger touch and visual observation. It was evaluated as ○ when the shape was hard to collapse when touched with a finger and the deformation at that time was small, and × when the shape immediately collapsed and touched with a finger. The results are summarized in Tables 1 and 2.

  Oxygen index: Measured with an ON-1D type apparatus manufactured by Suga Test Instruments Co., Ltd. using a thermally expandable test piece in accordance with JIS K 7201.

Sectional view of the seismic isolation device according to the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a Upper structure 1b Lower structure 2a Upper base plate 2b Lower base plate 3 Fireproof panel 4 Fireproof joint material 5 Seismic isolation device

Claims (6)

  A fireproof joint material comprising 100 parts by mass of a rubber component containing 20% by mass or more of a thermoplastic elastomer, 5 to 100 parts by mass of expansive graphite, 10 to 100 parts by mass of boric acid, and 10 to 300 parts by mass of an inorganic filler.   The fireproof joint according to claim 1, wherein the thermoplastic elastomer is a block copolymer comprising a block polymer mainly composed of a vinyl aromatic hydrocarbon monomer and a block polymer mainly composed of a conjugated diene monomer. Wood.   The fireproof joint material according to claim 1 or 2, wherein a mass ratio of boric acid to the inorganic filler is 1: 5 to 10: 1.   The fireproof joint material according to any one of claims 1 to 3, wherein the inorganic filler is aluminum hydroxide.   The gasket using the joint material for fire prevention of any one of Claims 1-4. A fireproof joint material for a base-isolated device fireproof panel comprising the fireproof joint material according to any one of claims 1 to 4.

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