JP2005126458A - Composition and molded foam produced by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition which has satisfactory fire resistance, is elastic and soft, sufficiently expands at a high temperature to fill gaps, has good shape-loss preventive properties, and is lightweight; a method for producing a molded foam from the composition; and a molded foam. <P>SOLUTION: The composition is prepared by compounding 100 pts.mass rubber component containing at least 20 mass% thermoplastic elastomer with 5-100 pts.mass thermally expandable graphite, 3-50 pts.mass microcapsules, 5-200 pts.mass shape-loss preventive, and 10-300 pts.mass inorganic filler, provided the sum of amounts of these compounded ingredients is 500 pts.mass or lower. The microcapsules may be expanded after incorporated into the composition or may be incorporated into the composition after pre-expanded. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a composition and a foam-molded article using the composition.

  When a fire breaks out in a building or ship vent, corridor, or railroad vehicle connection, the flame spreads rapidly through the vent, corridor, or connection, and spreads to the upper floors or adjacent rooms. It will encourage you. In order to prevent this fire spread, fire doors, fire shutters, and fire barriers in which a synthetic resin foam is interposed between a surface material and a back material made of a sheet metal are generally used.

  When these fire doors, fire shutters, and fire walls are exposed to high heat during a fire, the heat transfer between the surface material and the back surface material is different, resulting in large deformations and gaps in the connecting and connecting parts. There was a problem that heat and flame leaked to the opposite side, leading to the spread of fire. Therefore, fire-expandable materials are pre-installed in areas where these gaps are expected to occur, and these fire-expandable materials expand or foam during a fire to close the gaps and prevent the spread of fire. And measures to block outflow of smoke. These intumescent materials for fire prevention are required to have a heat insulating effect and a shape deformation preventing effect due to flame heat.

  Moreover, in a steel frame building, since a steel frame causes strength reduction by a fire, the construction method which covers the circumference | surroundings of these steel frames with a heat insulating material and prevents strength reduction is employ | adopted. As a covering material such as a steel frame or wall material for a building material, heat insulation and weight reduction are required.

  Examples of these inflatable compositions for fire protection include a base resin, an inorganic expansion agent and / or an organic expansion agent, and a polycarbonate resin, a polyphenylene sulfide resin, a polyether ketone resin, a polyamide resin, and a phenol as an anti-deformation agent. What contains resin etc. is known (for example, refer patent document 1). Since this explosive composition for fire protection contains a resin for preventing deformation, it is said that even if it receives flame heat, the expanded layer does not lose its shape and can keep its shape.

  However, these explosive compositions for fire protection, when exposed to flame heat for a long time, the resin for shape loss prevention itself melts or burns, so that sufficient fire resistance performance cannot be obtained during a fire or an expansion layer However, there was a problem that it was easily pulverized and hindered the treatment after fire. Further, the shape-preventing resin is relatively expensive, and there is a problem in terms of cost. In addition, there is a problem that elasticity and flexibility are not sufficient depending on applications.

  As an inflatable composition for fire protection imparted with elasticity and flexibility, there is known a fire-resistant elastic polyurethane flexible foam in which expansive graphite is contained as a flame retardant in a polyol and a polyisocyanate (see, for example, Patent Document 2). . However, these means have a problem that the effect of preventing the deformation is still insufficient. In addition, the means for producing polyurethane from a two-component reaction mixture of polyol and polyisocyanate has a problem that it is extremely difficult to blend a large amount of expansive graphite and sufficient fire resistance cannot be obtained.

In addition, a means is known in which an expansion body is stored or pasted on a door frame or a door body and a gap portion is closed during heating (see, for example, Patent Documents 3 and 4). However, these means have a problem that the expansion ratio at the time of a fire is inferior and the shape preventing property is not sufficient.
JP-A-9-176498 (second page: claims 1 to 4) Patent No. 2732435 (first page: claims 1-9, second page claims 10-12) JP-A-8-232553 (2nd page: claims 1 to 5) Japanese Patent Laid-Open No. 2000-54752 (second page: claims 1 to 2)

  An object of the present invention is to provide a composition having sufficient fire resistance, having both elasticity and flexibility, sufficiently expanding at a high temperature to fill a gap, and having good shape prevention and light weight, and a composition thereof An object of the present invention is to provide a foam molded article using the product.

  As a result of intensive studies, the present inventors have solved the above problems with a composition containing a specific composition in a rubber component containing a specific amount of a thermoplastic elastomer and a foam molded article using this composition. The inventors have found that the present invention can be accomplished and have completed the present invention.

  That is, the present invention is a composition containing a rubber component containing at least 20% by mass or more of a thermoplastic elastomer, a thermally expandable graphite, a microcapsule, a deformation preventing agent, and an inorganic filler, and the microcapsule is contained in the composition. It is a foamed molded product obtained by adding a foamed molded product and microcapsules obtained by heat treatment after being contained in the composition to a composition after having been preheated and subjected to an expansion treatment.

  The composition of the present invention exhibits heat insulating properties and light weight by expanding the contained microcapsules in the composition, and further expands the expandable graphite when exposed to high temperatures to form an expanded layer. It is formed, and has an effect that it does not easily become brittle even if it is exposed to a high temperature for a long time by containing an anti-deformation agent. For this reason, it is possible to stably obtain excellent fire resistance in a fire, and it is difficult for the expanded layer to be deformed, and the post-fire treatment can be performed smoothly and safely.

  The rubber component contains a thermoplastic elastomer in the inside thereof, and is for uniformly dispersing and holding the heat-expandable graphite, microcapsules, shape loss preventing agent, inorganic filler and the like to be described later. .

  Examples of these rubber components 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, There are fluoro rubber, natural rubber and synthetic rubber, and not only these simple substances but also two or more kinds may be mixed and used for improving kneadability, sheet moldability, extrusion moldability, press moldability, etc. .

  The thermoplastic elastomer contained in the rubber component has a hard segment and a soft segment therein. In thermoplastic elastomers, when the composition is heated and molded, the hard segment melts and develops fluidity to improve moldability, while the hard segment is molded at room temperature after molding. In addition to improving the dimensional stability of the product, rubber elasticity is exerted by the soft segment to improve strength and flexibility. Furthermore, in the event of a fire, the hard segment is melted by heat, and the expanded graphite is temporarily connected.

  The ratio of the hard segment and the soft segment constituting the thermoplastic elastomer is preferably 20/80 to 60/40, and particularly preferably 25/75 to 40/60. If the hard segment is less than 20%, the moldability of the composition is lowered, and if it exceeds 60%, the flexibility is undesirably lowered.

  The content of the thermoplastic elastomer with respect to the rubber component is preferably 20% by mass or more. When the content of the thermoplastic elastomer is less than 20% by mass, the dimensional stability of the foamed molded product cannot be maintained, and the strength and flexibility are insufficient, which is not preferable.

  As these thermoplastic elastomers, for example, various thermoplastic elastomers such as a vinyl chloride thermoplastic elastomer, a styrene thermoplastic elastomer, a polyolefin thermoplastic elastomer, and a polyester thermoplastic elastomer can be used, and in particular, a styrene thermoplastic elastomer is used. preferable.

  Examples of the styrenic thermoplastic elastomer include a block copolymer composed of a polymer block mainly composed of a vinyl aromatic compound and a polymer block mainly composed of a conjugated diene compound. Examples of vinyl aromatic compounds include styrene, p-methylstyrene, α-methylstyrene, vinyl xylene, monochlorostyrene, dichlorostyrene, and monobromostyrene. These are used in combination of two or more. Also good. Of these vinyl aromatic compounds, styrene is particularly preferred. Examples of the conjugated diene compound include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, and 1,3-pentadiene. These may be used alone or in combination of two or more. . Among these conjugated diene compounds, preferred are 1,3-butadiene and isoprene, and particularly preferred are 1,3-butadiene. These block copolymers of styrenic thermoplastic elastomer can be produced by known anionic polymerization.

  Thermally expandable graphite expands its volume by 100 times or more when exposed to a temperature of about 200 ° C. or higher. Although it is not particularly limited in the case of thermally expandable graphite, powders such as natural graphite and pyrolytic graphite are mixed with an inorganic acid such as sulfuric acid and nitric acid and a strong oxidizing agent such as concentrated nitric acid and permanganate. It is a crystalline compound that has been treated and maintains a graphite layered structure. These natural graphite and pyrolytic graphite powders can be used in various forms other than deoxidation treatment and 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 when the particle size is larger than 20 mesh, dispersibility is deteriorated when kneading into the rubber component, and physical properties such as strength are inevitably lowered.

  The content of the heat-expandable graphite can be appropriately set depending on the type of rubber component, desired expansion ratio, and the like, but usually 5 to 100 parts by mass is preferable with respect to 100 parts by mass of the rubber component. When the content of the heat-expandable graphite is less than 5 parts by mass, the expansion ratio at the time of fire occurrence is small, and when it exceeds 100 parts by mass, the expansion ratio increases, but the hardness of the resulting composition increases, Physical properties are also reduced. Moreover, when shape | molding in a sheet form, a moldability is inferior and surface skin worsens.

  A microcapsule is a plastic microsphere (average particle diameter of 5 to 50 μm) in which a low boiling point liquid or solid or a compound that generates a gas upon heating is enclosed in a thermoplastic resin shell. The encapsulated substance is gasified or generates gas, and the capsule expands. Examples of the substance to be included include low boiling point hydrocarbons and bicarbonates such as sodium bicarbonate.

  The content of the microcapsules is preferably 3 to 50 parts by mass with respect to 100 parts by mass of the rubber component. If the content of the microcapsule is less than 3 parts by mass, the lightweight and heat insulating properties of the foamed molded product are inferior, and if it exceeds 50 parts by mass, the strength of the foamed molded product is undesirably lowered. Further, the expansion start temperature of the microcapsule needs to be lower than that of the thermally expandable graphite.

  The deformation preventing agent is for stably fixing the expandable graphite in the foam molded article and preventing the foam molded article itself from being deformed.

  The content of the anti-deformation agent can be appropriately set depending on the amount of expansive graphite used, but usually 5 to 200 parts by mass with respect to 100 parts by mass of rubber. When the amount is less than 5 parts by mass, the effect of holding the expandable graphite is small and the shape-preventing performance is inferior. When the amount exceeds 200 parts by mass, the hardness of the composition increases and the flexibility is inferior.

  In addition, the ratio of the anti-deformation agent and the expandable graphite is preferably 1: 5 to 10: 1 by mass ratio, more preferably 1: 2 to 5: 1 in consideration of the balance of moldability, strength characteristics and the like. is there.

  An example of the shape loss preventing agent is boric acid. As boric acid itself, a product obtained by a known production method or a commercially available product can be used. Examples of these boric acids include orthoboric acid (H3BO3) and metaboric acid (HBO2), but orthoboric acid is usually preferable. Boric acid is usually used in powder form. In this case, the particle size of the boric acid powder is not particularly limited, but those having a relatively small particle size (usually about 100 μm or less, preferably about 20 μm or less) are preferable.

  The inorganic filler improves the moldability of the composition. The content of the inorganic filler is 10 to 300 parts by mass with respect to 100 parts by mass of the rubber component. If the amount is less than 10 parts by mass, the effect of improving the moldability is small. If the amount exceeds 300 parts by mass, the hardness of the composition becomes high and the flexibility is inferior. .

  Examples of the inorganic filler 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. Alternatively, two or more kinds may be mixed and used. The particle size of the inorganic filler is preferably 1 to 50 μm from the viewpoint of dispersibility in the rubber component.

  Among these inorganic fillers, aluminum hydroxide and magnesium hydroxide are preferable because the temperature rise is suppressed by the endothermic effect of water generated by the dehydration reaction during heating, and flame retardancy is improved.

  The total amount of heat-expandable graphite, microcapsule, shape loss preventing agent and inorganic filler added to the rubber component is preferably 500 parts by mass or less with respect to 100 parts by mass of the rubber component. If the total amount exceeds 500 parts by mass, not only the hardness of the composition is increased and the flexibility is deteriorated, but also the strength characteristics are deteriorated.

  The foamed molded article of the present invention comprises a composition containing a rubber component containing at least 20% by mass or more of a thermoplastic elastomer, a thermally expandable graphite, a microcapsule, a shape loss preventing agent, and an inorganic filler. And (a) a method of forming at a temperature not higher than the expansion start temperature of the thermally expandable graphite and not lower than the expansion start temperature of the microcapsule, and (b) the heat expandable graphite and the microcapsule. After molding at a temperature lower than the expansion start temperature, the microcapsule is expanded by heating at a temperature not lower than the expansion start temperature of the microcapsule and not higher than the expansion start temperature of the thermally expandable graphite in a heater such as a gear oven. Is.

  The foamed molded article of the present invention comprises a rubber component containing at least 20% by mass or more of a thermoplastic elastomer, thermally expandable graphite, microcapsules (average particle size of 50 to 150 μm) expanded in advance by heat treatment. A composition having a collapse preventing agent and an inorganic filler can also be obtained by kneading and molding at a temperature lower than the expansion start temperature of the thermally expandable graphite.

  As a device for kneading these compositions, there are kneading devices such as conventionally known mixers, Banbury mixers, kneader mixers, two rolls, etc., and as a device for molding the kneaded compositions, conventionally known press molding and roll molding. There are molding devices such as extrusion molding, calendar molding, and injection molding. Moreover, what is necessary is just to design the shape of a foaming molding suitably according to an installation place, such as a sheet form and tape form.

  The foamed molded article of the present invention is used in combination with commonly used plasticizers, softeners, anti-aging agents, processing aids, lubricants, tackifiers, vulcanizing agents, etc., as long as the effect is not impaired. It is good.

  Hereinafter, the present invention will be specifically described by way of examples. However, these examples do not limit the present invention. In addition, the part and% in the following description are based on a mass reference | standard.

"Experimental Examples 1-5"
In each experimental example, the following materials were used.
(1) Rubber component: Butyl rubber (manufactured by JSR Corporation, “Butyl 268”), EPDM (manufactured by DSM Japan Co., Ltd., “Keltan 2630A”), SBS (JSR Shell Corporation, “Clayton D1101”)
(2) Microcapsule: (Matsumoto Yushi Seiyaku Co., Ltd. “F-55” expansion start temperature 135 ° C.)
(3) Expansion-processed microcapsules: (Matsumoto Yushi Seiyaku Co., Ltd. “F-80ED”)
(4) Thermally expandable graphite: (manufactured by Sumikin Chemical Co., Ltd., “SS-3”, expansion start temperature 260 ° C.)
(5) Deformation prevention agent: boric acid (manufactured by BOR)
(6) Inorganic filler: Aluminum hydroxide (“Hijilite H-42” manufactured by Showa Denko KK)
(7) Softener: Naphthenic oil (“NP-24” manufactured by Idemitsu Kosan Co., Ltd.)
(8) Processing aid: Ester lubricant (Riken Vitamin Co., Ltd., “Emaster 510P”)

"Example 1"
The components shown in the column of the composition in Table 1 were uniformly kneaded with a 3 liter kneader, and the resulting composition was formed into a sheet having a thickness of 5 mm with a roll. This sheet was cut into a strip shape having a thickness of 5 mm, a width of 30 mm, and a length of 150 mm, and the microcapsules were expanded by heating in a gear oven adjusted to 140 ° C. for 10 minutes, and the thickness was 8 mm, the width was 42 mm, and the length was 168 mm. The foamed molded product was obtained.

"Example 2"
The components shown in the blending column of Table 1 were uniformly kneaded with a 3 liter kneader, and the obtained composition was formed into a sheet having a thickness of 5 mm while expanding the microcapsules with a heating roll adjusted to 155 ° C. Molded. This sheet was cut into a strip shape having a width of 30 mm and a length of 150 mm to obtain a foam molded article.

"Example 3"
The components shown in the column of Table 1 were uniformly kneaded with a 3 liter kneader, and the resulting composition was molded into a sheet having a thickness of 5 mm with a heating roll adjusted to 120 ° C. This sheet was cut into a strip shape having a width of 30 mm and a length of 150 mm to obtain a foam molded article.

"Example 4"
The components shown in the blending column of Table 1 were uniformly kneaded with a 3 liter kneader, and the resulting composition was molded into a 5 mm thick sheet with a heating roll adjusted to 120 ° C. This sheet was cut into a strip shape having a width of 30 mm and a length of 150 mm to obtain a foam molded article. The “microcapsules obtained by expanding F-55” in Experimental Example 3 were obtained by heat-treating the microcapsules “F-55” used in Example 1 for 5 minutes in a gear oven adjusted to 145 ° C. It is what was done.

"Comparative Example 1"
The components shown in the formulation column of Table 1 were uniformly kneaded with a 3 liter kneader, and the resulting composition was formed into a sheet having a thickness of 5 mm with a roll. This sheet was cut into a strip shape having a width of 30 mm and a length of 150 mm to obtain a thermally expandable molded body.

"Comparative Example 2"
The components shown in the formulation column of Table 1 were uniformly kneaded with a 3 liter kneader, and the resulting composition was formed into a sheet having a thickness of 5 mm with a roll. This sheet was cut into a strip shape having a width of 30 mm and a length of 150 mm to obtain a thermally expandable molded body.

In the examples and comparative examples, the following characteristics were evaluated and summarized in the evaluation column of Table 1.
The measuring method of each characteristic is shown below.
Specific gravity: A value measured with an electronic hydrometer (Mirage Trading, Inc .: EW120SG) according to JIS K 6220.
Fire resistance: Set a test body with a foamed molded body or a thermally expandable molded body sandwiched between a 10 mm thick gypsum board and a 1 mm thick iron plate in the electric furnace so that the gypsum board surface is inside. When the furnace temperature was raised to a predetermined temperature in 1 hour in accordance with JIS A1304, no flame was emitted from the panel heating side to the non-heating side for more than 10 seconds. This is what caused the eruption of
Shape retention: Samples that have been tested for fire resistance are evaluated for their shape retention by touch and visual inspection. What was deformed and deformed?

Claims (10)

  A composition comprising a rubber component containing at least 20% by mass or more of a thermoplastic elastomer, and thermally expandable graphite, microcapsules, a shape loss preventing agent, and an inorganic filler.   2. The composition according to claim 1, wherein the thermoplastic elastomer is a styrene elastomer comprising a polymer block mainly composed of a vinyl aromatic compound and a polymer block mainly composed of a conjugated diene compound.   With respect to 100 parts by mass of the rubber component, 5 to 100 parts by mass of thermally expandable graphite, 3 to 50 parts by mass of microcapsules, 5 to 200 parts by mass of an anti-deformation agent, and 10 to 300 parts by mass of an inorganic filler, The composition according to claim 1 or 2, wherein the total amount is 500 parts by mass or less.   The composition according to any one of claims 1 to 3, wherein the shape loss preventing agent is boric acid.   The composition according to any one of claims 1 to 4, wherein the inorganic filler is aluminum hydroxide and / or magnesium hydroxide.   The composition according to any one of claims 1 to 5, wherein the anti-deformation agent and the thermally expandable graphite are blended in a mass ratio of 1: 5 to 10: 1.   The composition according to any one of claims 1 to 6, wherein the microcapsule has been subjected to an expansion treatment in advance.   A foamed molded article obtained by molding the composition according to any one of claims 1 to 6 at a temperature not higher than an expansion start temperature of thermally expandable graphite and not lower than an expansion start temperature of microcapsules.   After molding the composition according to any one of claims 1 to 6 below the expansion start temperature of thermally expandable graphite and microcapsules, the expansion start temperature of the microcapsules is below the expansion start temperature of the thermally expandable graphite. A foamed molded product obtained by heat treatment as described above. A foam molded article obtained by molding the composition according to claim 7 at a temperature not higher than the expansion start temperature of thermally expandable graphite.