JP2007297856A - Fire-resistant cover sheet for steel frame - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fire-resistant cover sheet for a steel frame which is easy to construct and can give, even as thin as 4 mm or less, a fire-resistant performance for more than two hours to a steel frame. <P>SOLUTION: The fire-resistant cover sheet is made of a laminate formed by laminating a shape-holding expanded layer and an insulating reinforced layer. The shape-holding expanded layer contains a thermoplastic resin and/or rubber, thermally expandable graphite, ammonium poly-phosphate, and calcium carbonate. The insulating reinforced layer contains a thermoplastic resin and/or rubber, a liquid component, thermally expandable graphite and a plate-like inorganic filler having an average aspect ratio of 1.5 or higher. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a fireproof covering sheet for steel frame that is easy to construct and can impart fireproof performance of 2 hours or more to a steel frame even with a thickness of 4 mm or less.

Light steel frames are used for beams, pillars, etc., which are structural materials of buildings, as the height of buildings increases. When such a steel frame is exposed to a fire flame and exceeds a certain temperature, it buckles and cannot retain its shape, leading to the collapse of the building. Accordingly, fire resistance performance standards are defined by the Building Standard Law and JIS A 1304 for steel frames used as structural materials for buildings. Different standards are set depending on the number of floors used from the viewpoint of load capacity. For example, in the case of a building with 5 stories or more, if the number of floors counted from the top floor is 2 or more and 4 or less, 1 hour While fire resistance is required, floors counted from the top floor of 5 or more and less than 14 require 2 hours of fire resistance, and floors counted from the top floor of 15 or more require fire resistance of 3 hours. It is done. In addition, international standards such as ISO 834 are also established as evaluation standards for such fire resistance.

As a method for imparting fire resistance to a steel frame, a method of applying a fireproof coating is common. Examples of fire-resistant coating methods that provide high fire resistance of 2 hours or more that can be used on high-rise buildings of 5 floors or higher on steel frames include, for example, wiping of inorganic fibers, sticking of inorganic fibers processed into mats, and fire-resistant paints Thick coating etc. are performed. However, these methods have various problems such as adverse effects on the human body and the environment, problems of workability, and space saving problems as buildings.

On the other hand, in recent years, highly flame-retardant materials made of a thermally expandable resin composition or the like have been proposed. For example, Patent Document 1 discloses a thermally expandable fire-protective composition suitable for closing a through-hole of a fire-protective compartment containing boric acid as an inorganic expander and an inorganic deformation preventing agent, Patent Document 2 discloses a flame retardant composition containing a polymer and a thermally expandable graphite, and further a metal oxide selected from the group consisting of antimony, bismuth, zirconium, molybdenum, tungsten, boron, aluminum, magnesium and zinc. Patent Document 3 discloses a resin composition containing polyolefin thermally expandable graphite and a phosphorus compound, and Patent Document 4 and Patent Document 5 disclose thermal expansion with respect to a thermoplastic resin or rubber. A heat-expandable composition containing expansive graphite, a phosphorus compound, and an inorganic filler is disclosed. Patent Document 6 discloses a fireproof covering formed by laminating an auxiliary heat insulating layer and a non-combustible material on a heat-expandable fireproof layer. A steel structure is disclosed, and Patent Document 7 discloses a thermally expandable sheet having shape-retaining properties containing thermally expandable graphite, a phosphorus compound, a water-containing inorganic substance, and a metal carbonate with respect to a thermoplastic resin or rubber ( Disclosed is a multilayer sheet comprising a layer A and a thermally expandable sheet (B) layer containing a thermally expandable graphite, a water-containing inorganic substance, or a metal carbonate that does not have a shape-retaining property with respect to a thermoplastic resin or rubber. Has been.
If what processed these flame-retardant materials into the sheet form is used as a coating | covering material, fire resistance can be provided to steel frame with high workability.

However, these flame retardant materials were developed with the intention of so-called “flame retardant”, and therefore the performance as a fire-resistant coating material imparting fire resistance to the steel frame was insufficient. . In particular, in order to give the steel frame a fire resistance of 2 hours or more that can be used for high-rise buildings with 5 floors or more, the initial thickness of the sheet is increased, the thickness of the auxiliary material to be laminated is increased, and the number of laminated sheets is increased. It is necessary to increase it. For this reason, there is a problem in that the weight increases during construction, the workability deteriorates, the disadvantage that the number of man-hours increases, the merit of space saving decreases, and the cost increases.
Japanese Patent No. 3455801 JP-A-8-302209 JP-A-6-25476 Japanese Patent No. 3299899 JP 10-7838 A Japanese Patent No. 3581597 Japanese Patent No. 3688508

An object of this invention is to provide the fireproof coating sheet for steel frames which is easy to construct in view of the said present condition, and can provide fire resistance performance for 2 hours or more to a steel frame even if it is 4 mm or less in thickness.

The present invention is a fireproof coating sheet for steel frame comprising a laminate in which a shape-retaining expanded layer and a heat-insulating reinforcing layer are laminated, wherein the shape-retaining expanded layer is made of thermoplastic resin and / or rubber, thermal expansion Containing heat-resistant graphite, ammonium polyphosphate, and calcium carbonate, and the heat-insulating reinforcing layer is a thermoplastic resin and / or rubber, liquid component, heat-expandable graphite, and plate having an aspect ratio of 1.5 or more. It is a fireproof coating sheet for steel frames containing an inorganic filler.
The present invention is described in detail below.

As a result of intensive studies, the inventors of the present invention are composed of a specific composition and a shape-retaining inflatable layer specialized in shape-retaining properties that can be expanded while having shape-retaining properties. In addition, a laminate with a heat insulation enhancement layer specialized for heat insulation that can exhibit higher heat insulation is used, and such a laminate is used with the heat insulation reinforcement layer side on the steel frame side and the shape-retaining expansion layer side on the surface side. Only when the steel frame was coated in such a manner, the fire resistance performance was remarkably improved, and it was found that the fire resistance performance of 2 hours or more could be imparted to the steel frame even at a thickness of 4 mm or less, and the present invention was completed. .

The steel frame fireproof covering sheet of the present invention comprises a laminate in which a shape-retaining expansion layer and a heat insulating reinforcing layer are laminated.
The shape-retaining expanded layer plays a role of heat shielding and flame shielding for the heat-insulating reinforcing layer by being on the surface side when the steel frame is coated with the fireproof covering sheet for steel frame of the present invention. is there. On the other hand, the said heat insulation reinforcement | strengthening layer bears the role which expands at comparatively low temperature with respect to the heat | fever transmitted from the said shape maintenance expansion | swelling layer, and exhibits high heat insulation.

The shape-retaining expanded layer contains a plastic resin and / or rubber, thermally expandable graphite, ammonium polyphosphate, and calcium carbonate.
The plastic resin and rubber are not particularly limited. For example, polyolefin resins such as polypropylene resins, polyethylene resins, poly (1-) butene resins, polypentene resins, polystyrene resins, acrylonitrile-butadiene-styrene resins. Resin, polycarbonate resin, polyphenylene ether resin, acrylic resin, polyamide resin, polyvinyl chloride resin, phenol resin, polyurethane resin, polybutene, polychloroprene, polybutadiene, polyisobutylene, butyl rubber, nitrile rubber, isoprene rubber , Styrene-butadiene rubber, chlorinated butyl rubber, ethylene-propylene rubber, chlorosulfonated polyethylene, acrylic rubber, epichlorohydrin rubber, polyvulcanized rubber, silicone rubber, fluorine rubber, urea Ngomu, and the like. These thermoplastic resins and rubbers may be used alone or in combination of two or more.

The thermoplastic resin and rubber may be subjected to crosslinking or modification as long as the object of the present invention is not impaired.
The cross-linking is not particularly limited, and examples thereof include cross-linking by methods usually used for thermoplastic resins and rubbers such as a method using a cross-linking agent, a method using a peroxide, a method of performing electron irradiation, and the like.
The modification is not particularly limited, and examples thereof include modification by a conventional method for thermoplastic resins such as maleic acid modification and grafting, and rubber.

In the shape-retaining expanded layer, the thermally expandable graphite plays a role as an expanding agent.
In the present specification, the heat-expandable graphite refers to powders such as natural scaly graphite, pyrolytic graphite, and quiche graphite, inorganic acids such as concentrated sulfuric acid, nitric acid, and selenic acid, concentrated nitric acid, perchloric acid, and perchlorate. , A graphite intercalation compound produced by treatment with a strong oxidizing agent such as permanganate, dichromate, hydrogen peroxide, etc., and means a crystalline compound that maintains the layered structure of carbon .

As the heat-expandable graphite, those neutralized with ammonia, an aliphatic lower amine, an alkali metal compound, an alkaline earth metal compound or the like are preferable.
The aliphatic lower amine is not particularly limited, and examples thereof include monomethylamine, dimethylamine, trimethylamine, ethylamine, propylamine, and butylamine. The alkali metal compound or alkaline earth metal compound is not particularly limited, and examples thereof include hydroxides such as potassium, sodium, calcium, barium, and magnesium, oxides, carbonates, sulfates, and organic acid salts. .
As a commercial product of the thermally expandable graphite thus neutralized, for example, UCAR CARB
Examples thereof include “GRAFGUARD” manufactured by ON, “GREP-EG” manufactured by Tosoh Corporation, and the like.

As the thermally expandable graphite, those having a particle size of 200 to 20 mesh are suitable. If it is less than 200 mesh, the expandability of the heat-expandable graphite may be small, and a sufficient fire-resistant and heat insulating effect may not be obtained. If it exceeds 20 mesh, the dispersibility in thermoplastic resin and / or rubber will deteriorate. In some cases, the physical properties of the obtained sheet may deteriorate.

A blending amount of the thermally expandable graphite in the shape-retaining expanded layer is not particularly limited, but a preferable lower limit with respect to 100 parts by weight of the resin component is 20 parts by weight, and a preferable upper limit is 100 parts by weight. If the amount is less than 20 parts by weight, the thermal expansibility may be insufficient, and a sufficient heat shielding function may not be achieved. If the amount exceeds 100 parts by weight, the physical properties may deteriorate and the surface may crack, or the weight may be reduced during combustion. Combustion residue may collapse on the way without being able to endure. A more preferred lower limit is 30 parts by weight, a more preferred upper limit is 80 parts by weight, a still more preferred lower limit is 45 parts by weight, and a still more preferred upper limit is 65 parts by weight.
In the present specification, the resin component includes, in addition to the thermoplastic resin and / or rubber, a plasticizer and a tackifier that are added to modify the resin binder.

The ammonium polyphosphate serves as a shape-retaining agent in the shape-retaining expanded layer.
The compounding amount of the ammonium polyphosphate in the shape-retaining expanded layer is not particularly limited, but a preferable lower limit with respect to 100 parts by weight of the resin component is 20 parts by weight, and a preferable upper limit is 200 parts by weight. If the amount is less than 20 parts by weight, the shape retention ability may be insufficient at the time of a fire, and the heat shielding and flame shielding functions may not be sufficiently achieved. If the amount exceeds 200 parts by weight, flexibility as a sheet-like molded article may be obtained. May be difficult to mold. A more preferred lower limit is 30 parts by weight, a more preferred upper limit is 150 parts by weight, a still more preferred lower limit is 60 parts by weight, and a still more preferred upper limit is 120 parts by weight.

As the weight ratio of the thermally expandable graphite and ammonium polyphosphate in the shape-retaining expanded layer, the preferred lower limit of the value of thermally expandable graphite / ammonium polyphosphate is 0.01, and the preferred upper limit is 9. If it is less than 0.01, the expansibility becomes insufficient and sufficient fire resistance performance may not be exhibited. If it exceeds 9, the combustion residue may become brittle and the shape retention effect may not be exhibited. A more preferred lower limit is 0.3, a more preferred upper limit is 7, a still more preferred lower limit is 0.5, and a still more preferred upper limit is 5.

The calcium carbonate plays a role of further improving the shape-retaining property by forming a stronger combustion residue by interacting with ammonium polyphosphate in the shape-retaining expanded layer.
Although it does not specifically limit as a compounding quantity of the said calcium carbonate in the said shape maintenance expansion | swelling layer, The preferable minimum with respect to 100 weight part of resin components is 20 weight part, and a preferable upper limit is 200 weight part. If the amount is less than 20 parts by weight, a sufficient shape retention effect cannot be obtained, and the combustion residue may become brittle, so that sufficient heat shielding and flame shielding effects may not be exhibited. The flexibility as a molded body is inferior, and molding may be difficult. A more preferred lower limit is 30 parts by weight, a more preferred upper limit is 150 parts by weight, a still more preferred lower limit is 60 parts by weight, and a still more preferred upper limit is 120 parts by weight.

As a weight ratio of the calcium carbonate and ammonium polyphosphate in the shape-retaining expanded layer, the preferable lower limit of the calcium carbonate / ammonium polyphosphate value is 0.6, and the preferable upper limit is 1.5. If it is less than 0.6, the combustion residue becomes sticky at the time of a fire, and it may cause dripping of the combustion residue or the shape retention may be inferior. If the steel frame is bent, the combustion residue may not follow and may easily break. A more preferred lower limit is 0.8, a more preferred upper limit is 1.2, a still more preferred lower limit is 1.0, and a still more preferred upper limit is 1.1.

The shape-retaining expanded layer contains fibers such as ceramic fibers, glass fibers, and carbon fibers for the purpose of improving shape-retaining properties, or has a woven fabric / net-like material made of metal as a reinforcing material. Also good.

The shape-retaining expanded layer is a flame retardant, an antioxidant, a metal hazard inhibitor, an antistatic agent, a stabilizer, a crosslinking agent, a lubricant, a softener, a pigment, and a tackifier as long as the object of the present invention is not impaired. Conventionally known additives such as these may be contained.

The additive is not particularly limited, for example, silica, diatomaceous earth, alumina, zinc oxide, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, ferrites, calcium hydroxide, magnesium hydroxide, Aluminum hydroxide, basic magnesium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, dosonite, hydrotalcite, calcium sulfate, barium sulfate, gypsum fiber, calcium silicate, talc, clay, mica, montmorillonite, bentonite, activated clay, Sepiolite, imogolite, sericite, glass fiber, glass beads, silica-based balun, aluminum nitride, boron nitride, silicon nitride, carbon black, graphite, carbon fiber, carbon balun, charcoal powder, various metal powders, potassium titanate , Magnesium sulfate, lead zirconate titanate, aluminum borate, molybdenum sulfide, silicon carbide, stainless steel fiber, various magnetic powder, slag fibers, fly ash, inorganic phosphorus compounds, and the like. These additives may be used alone or in combination of two or more.

Next, the heat insulation reinforcement | strengthening layer in the fireproof coating sheet for steel frames of this invention is demonstrated.
The heat insulating reinforcing layer contains a thermoplastic resin and / or rubber, thermally expandable graphite, a liquid component, and a plate-like inorganic filler having an aspect ratio of 1.5 or more.
It does not specifically limit as said thermoplastic resin and rubber | gum, The thing similar to the said shape retention expansion | swelling layer can be used.
The thermoplastic resin and rubber constituting the shape-retaining expanded layer and the heat-insulating reinforcing layer may be the same or different, but when a part of the thermoplastic resin or rubber is also common In the case of laminating and processing by adhesive coating, the adhesive strength increases and the range of selection of the adhesive also widens. Moreover, when using the rubber | gum which has self-adhesiveness like butyl rubber, the direction where it uses together with the said shape maintenance expansion | swelling layer and a heat insulation reinforcement | strengthening layer may perform a lamination process easily. However, this is not the case when the effect of each layer on the fire resistance is increased by changing the resin for each layer.

The heat-expandable graphite is not particularly limited, and the same material as the shape-retaining expandable layer can be used.
Although it does not specifically limit as a compounding quantity of the said heat expansible graphite in the said heat insulation reinforcement | strengthening layer, The preferable minimum with respect to 100 weight part of resin components is 20 weight part, and a preferable upper limit is 100 weight part. If the amount is less than 20 parts by weight, the thermal expansibility may be insufficient, and a sufficient heat shielding function may not be achieved. If the amount exceeds 100 parts by weight, the physical properties may deteriorate and the surface may crack, or the weight may be reduced during combustion. Combustion residue may collapse on the way without being able to endure. A more preferred lower limit is 30 parts by weight, a more preferred upper limit is 80 parts by weight, a still more preferred lower limit is 45 parts by weight, and a still more preferred upper limit is 65 parts by weight.

In the present specification, the liquid component means a component having a melting point of room temperature or lower.
The liquid component plays a role of imparting low-temperature expansibility to exhibit high heat insulation in the heat-insulating reinforcing layer, as well as providing adhesiveness, improving cold resistance, and adjusting fluidity. .
The liquid component is not particularly limited. For example, phthalic acid plasticizer, phosphate ester plasticizer, adipic acid ester plasticizer, sabatic acid ester plasticizer, ricinoleic acid ester plasticizer, polyester plasticizer , Epoxy plasticizer, chlorinated paraffin and the like. Moreover, fats and oils, such as animal fats and oils, vegetable fats and oils, mineral oil, silicone oil, can also be used as said liquid component. Furthermore, a low molecular weight polymer having a low viscosity can also be used as the liquid component.

The polymer low polymer is not particularly limited. For example, polybutene, natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), 1,2-polybutadiene rubber (1,2-BR), styrene -Butadiene rubber (SBR), chloroprene rubber (CR), nitrile rubber (NBR), butyl rubber (IIR), ethylene-propylene rubber (EPM, EPDM), chlorosulfonated polyethylene (CSM), acrylic rubber (ACM, ANM), Examples include low polymers such as epichlorohydrin rubber (CO, ECO), polyvulcanized rubber (T), silicone rubber (Q), fluorine rubber (FKM, FZ), and urethane rubber (U). Natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), 1,2-polybutadiene rubber (1,2-BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), nitrile rubber (NBR) ), Butyl rubber (IIR), ethylene-propylene rubber (EPM, EPDM), chlorosulfonated polyethylene (CSM), acrylic rubber (ACM, ANM), epichlorohydrin rubber (CO, ECO), polyvulcanized rubber (T), silicone rubber (Q), low polymers such as fluoro rubber (FKM, FZ) and urethane rubber (U).

The blending amount of the liquid component in the heat insulation reinforcing layer is not particularly limited, but the preferable lower limit of the content in 100 parts by weight of the resin component is 20% by weight, and the preferable upper limit is 70% by weight.
If it is less than 20% by weight, a sufficient low-temperature expansion effect may not be obtained, and if it exceeds 70% by weight, the fluidity during heating will increase, resulting in dripping and poor fire resistance. There is. A more preferred lower limit is 30% by weight, and a more preferred upper limit is 60% by weight.

Although it does not specifically limit as said plate-shaped inorganic filler whose aspect ratio is 1.5 or more, For example, a talc, mica, a sericite, plate glass, metal foil, a metal oxide, etc. can be used. Of these, talc and mica are preferably used. As these plate-like inorganic fillers, those obtained by treating the surface with a metal oxide or an organic substance may be used. Moreover, these plate-shaped inorganic fillers may be used independently and may use 2 or more types together.

The heat-insulating reinforcing layer contains a plate-like inorganic filler having an aspect ratio of 1.5 or more, thereby peeling the inorganic filler and the resin component by heating and separating the resin component from the inorganic filler. Since it can be expanded, the expansion ratio of the entire combustion residue after heating, particularly the expansion ratio in the initial stage of expansion below 300 ° C., can be increased, and the heat insulation of the combustion residue can be greatly improved. Moreover, since the said heat insulation reinforcement | strengthening layer contains the plate-shaped inorganic filler whose said aspect ratio is 1.5 or more, a combustion residue decomposes | disassembles into flake shape and a space | gap is not formed in a combustion residue, By convection The influence of heat conduction can be reduced. If the aspect ratio is less than 1.5, even if the inorganic filler and the resin component are peeled off by heating, the resin component cannot be sufficiently separated from the inorganic filler. May not improve the thermal insulation. The aspect ratio is preferably 5 or more, more preferably 10 or more, and still more preferably 20 or more.
The upper limit of the aspect ratio is not particularly limited, but the substantial upper limit is about 300 to 400. Moreover, the effect of the present invention cannot be obtained with a fibrous inorganic filler.

The aspect ratio is a value obtained by dividing the average length by the average thickness (average length / average thickness). The average length for obtaining the aspect ratio is obtained by the following formula (1).
Average length = {(average major axis length + average minor axis length) / 2} (1)
In addition, the average thickness, the average major axis length, and the average minor axis length are arbitrarily sampled from 20 samples, and the thickness, major axis length, and minor axis length are subjected to image processing by an electron microscope. It is calculated from the average measured by In the image processing, the major axis length and the minor axis length can be calculated by elliptically approximating the plane portion.

The plate-like inorganic filler having an aspect ratio of 1.5 or more has a preferable lower limit of the average particle diameter of 1 μm and a preferable upper limit of 200 μm. If within the above range, the plate-like inorganic filler having an aspect ratio of 1.5 or more and the resin component can be peeled off by heating, and the resin component can be effectively separated, thereby increasing the expansion ratio. The heat insulation property of the combustion residue can be greatly improved. If it is less than 1 μm, even if the plate-like inorganic filler having an aspect ratio of 1.5 or more and the resin component are peeled off by heating, the resin component cannot be sufficiently separated, so the expansion ratio does not increase, The thermal insulation of combustion residues may not improve. When it exceeds 200 μm, the contact area between the plate-like inorganic filler having an aspect ratio of 1.5 or more and the resin component is increased, and the plate-like inorganic filler and resin having an aspect ratio of 1.5 or more are heated by heating. Since the energy required to separate and separate the components increases, it becomes difficult to separate the resin components at low temperatures, and the expansion ratio at low temperatures may not be increased. A more preferred lower limit is 5 μm, and a more preferred upper limit is 100 μm.

The average particle diameter of the plate-like inorganic filler having an aspect ratio of 1.5 or more can be expressed using an average value obtained by a laser analysis method. Although it does not specifically limit as a measuring method by the said laser analysis method, For example, it can measure by a conventionally well-known method using measuring apparatuses, such as MastersizerX (made by Malvern Instrument Ltd).

The blending amount of the plate-like inorganic filler having an aspect ratio of 1.5 or more in the heat insulating reinforcing layer is preferably 100 parts by weight and preferably 400 parts by weight with respect to 100 parts by weight of the resin component. If it is less than 100 parts by weight, even if peeling between layers occurs due to heating, the effect of separating the resin component cannot be obtained sufficiently, so that the resulting fireproof coating sheet for steel frames is difficult to crack and expands at low temperature. May not be promoted and sufficient heat resistance may not be exhibited. If the amount exceeds 400 parts by weight, the proportion of the resin component decreases, resulting in a decrease in physical properties of the resulting steel fireproof coating sheet, cracking of the surface, inability to withstand its own weight during combustion, and combustion residues falling on the way There are things to do. A more preferred lower limit is 200 parts by weight, and a more preferred upper limit is 350 parts by weight.

The heat-insulating reinforcing layer may contain a shape-retaining agent such as ammonium polyphosphate, calcium carbonate, or boric acid for the purpose of imparting shape-retaining properties. Thereby, a big drop of combustion residue can be prevented at the time of combustion. However, since the low temperature expansibility and the heat insulation may be lowered, the amount of the shape retention agent is preferably less than 30 parts by weight with respect to 100 parts by weight of the resin component.

The heat-insulating reinforcing layer may contain fibers such as ceramic fiber, glass fiber, and carbon fiber for the purpose of improving shape retention, or may include a woven fabric / net-like material made of metal as a reinforcing material. Good. When the heat-insulating reinforcing layer contains glass fibers, the use of boron-containing components such as boric acid and borax can promote the melting of the glass fibers and improve the shape retention ability.

The above heat-insulating reinforcing layer is a flame retardant, an antioxidant, a metal harm-preventing agent, an antistatic agent, a stabilizer, a crosslinking agent, a lubricant, a softening agent, a pigment, a tackifier, etc., as long as the object of the present invention is not impaired. These conventionally known additives may be contained.

The heat-insulating reinforced layer preferably has a volume expansion ratio of 2 times or more when heated at a temperature 10 ° C. or more lower than the thermal expansion start temperature of the thermally expandable graphite. If the volume expansion ratio of 2 times or more cannot be obtained at a temperature lower by 10 ° C. or more, the high fire resistance intended by the present invention may not be obtained.

The steel frame-coated fireproof sheet of the present invention preferably has an aluminum base on one or both sides of the shape-retaining expanded layer and / or the heat-insulating reinforcing layer. Since a heat reflecting effect is imparted by laminating an aluminum base material on the opposite side of the heat-insulating reinforcement layer of the shape-retaining expansion layer, fire resistance can be further improved. Moreover, the said heat insulation reinforcement | strengthening layer which is comparatively inferior in shape retentivity can be firmly hold | maintained by laminating | stacking an aluminum base material on the said heat insulation reinforcement | strengthening reinforcement layer side of the said shape maintenance expansion layer. By laminating an aluminum base material on the opposite side of the heat-insulating reinforcing layer to the shape-retaining expandable layer, an effect of preventing a large drop of combustion residue of the heat-insulating reinforcing layer is imparted. In addition, when laminating an aluminum base material between the shape-retaining expanded layer and the heat-insulating reinforcing layer, the aluminum base material may be stacked on both the shape-retaining expanded layer and the heat-insulating reinforcing layer. And an aluminum base material may be laminated | stacked only on one side of the said shape maintenance expandable layer and a heat insulation reinforcement | strengthening layer.

Although it does not specifically limit as said aluminum base material, For example, the aluminum laminated base material laminated | stacked with the resin film other than aluminum foil, an aluminum glass cloth base material, etc. can be used. In particular, the aluminum glass cloth base material can be expected to have an effect of maintaining the shape of the combustion residue of the shape-retaining expansion layer by melting the glass cloth when the aluminum melts at a temperature higher than the melting temperature of aluminum during a fire. To preferred.

The method for producing the steel frame-coated fireproof sheet of the present invention is not particularly limited, and a general resin sheet forming method is used. For example, the components constituting each layer are melt-kneaded using a kneader or a feeder ruder. Then, the method etc. which apply | coat the obtained resin composition on the said aluminum base material with a calendar molding method or a twin screw extruder are mentioned.
The shape-retaining expanded layer and the heat-insulating reinforcing layer may be laminated and laminated using a multi-layer laminating machine, or may be laminated using screws or the like during construction.

The steel frame coated fireproof sheet of the present invention is extremely excellent in fireproof performance, and can be imparted with fireproof performance of 2 hours or more even when the thickness is 4 mm or less by being applied to the steel frame. Both fire resistance and space saving can be achieved. When the coated fireproof sheet for steel frame of the present invention is applied, for example, to a place where a fire resistance performance of 1 hour is required, a sufficient effect can be obtained even if it is made thinner, and a high space saving effect can be exhibited.

When the steel frame is coated with the coated fireproof sheet for steel frame of the present invention, it is preferable to coat the steel frame such that the heat-insulating reinforcing layer side is on the steel frame side and the shape-retaining expansion layer side is on the surface side. When covered in such a manner, a predetermined fire resistance improvement effect is easily obtained. A method for coating a steel frame with the coated fireproof sheet for steel frame according to the present invention, wherein the steel frame is coated with the above-mentioned coated fireproof sheet for steel so that the heat-insulating reinforcing layer side is on the steel side and the shape-retaining expansion layer side is on the surface side. The steel coating method is also one aspect of the present invention.

The coated refractory sheet for steel frames of the present invention usually has a large area and is heavy and difficult to handle. Therefore, it is preferable to cut and construct it to a size that is easy to work with. However, if construction is not performed with a single sheet that is unbroken with respect to the steel frame, there is always a joint, and the joint is a weak point in fire resistance, and the fire resistance is greatly affected by the treatment of the joint. . In the steel coating method according to the present invention, it is preferable that the joint portion is abutted at the end and an aluminum tape is applied to the surface of the butted portion. The fire resistance can be exhibited most effectively in the event of a fire by simply affixing the aluminum tape so as not to physically open the end part without being overlapped with the joint part. In addition, in FIG. 1, the case of end part butt | butting and aluminum tape construction is shown as an example of construction of the covering fireproof sheet for steel frames of this invention, and the case of overlap construction is shown in FIG.

According to the present invention, it is possible to provide a fireproof coating sheet for a steel frame that is easy to construct and can impart a fireproof performance of 2 hours or more to a steel frame even with a thickness of 4 mm or less.

Hereinafter, embodiments of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(Examples 1 to 3 and Comparative Examples 1 and 2)
After melt-kneading each formulation shown in Table 1 using a kneader, the obtained resin composition was applied onto an aluminum substrate by a calender molding method and dried to obtain a predetermined thickness shape-retaining expanded layer and A heat-insulating reinforcing layer was produced. These layers were laminated in the configuration shown in Table 2 to obtain a fireproof coating sheet for steel frames.

Each material used in Table 1 is as follows. Butyl rubber (“Butyl # 065” manufactured by ExxonMobil Chemical Co., Ltd.), polybutene (“Polybutene HV-100” manufactured by Nippon Petrochemical Co., Ltd.), hydrogenated petroleum resin (“Imabe P-125” manufactured by Idemitsu Petrochemical Co., Ltd.), thermal expansion -Based graphite ("Frame Cut GREP-EG" manufactured by Tosoh Corporation), ammonium polyphosphate ("EXOLIT AP422" manufactured by Clariant), silica ("MILLSIL M6" manufactured by SIBERCO), average particle diameter: 37 [mu] m, aspect ratio: 1.1 ), Calcium carbonate (“BF300” manufactured by Bihoku Flour & Chemical Co., Ltd., average particle size: 8 μm, aspect ratio: 1.2), talc (“Talc SW” manufactured by Nippon Talc Co., Ltd.), average particle size: 12 μm, aspect ratio: 20 ), Mica 1 (“A-21” manufactured by Yamaguchi Mica Co., Ltd., average particle size: 23 μm, aspect ratio: 80), mica 2 (Yamaguchi Mica Co., Ltd.) "B-82", average particle diameter: 180 [mu] m, aspect ratio: 110)

(Evaluation)
About the obtained heat insulation reinforcement | strengthening layer and the coating fireproof sheet for steel frames, the following method evaluated.
The results are shown in Table 2.

(1) Low-temperature expansibility of the heat-insulating reinforcing layer In a state where the heat-insulating reinforcing layer cut to a size of 25 × 25 mm was placed on an aluminum pan, it was put into an electric furnace set at 230 ° C. and heated for 20 minutes. It was taken out later. The expansion ratio of the combustion residue was calculated by the following method.
Expansion ratio during low-temperature heating (times) = (volume after heating) / (volume before heating)
The state of 230 ° C. electric furnace heating is a simple reproduction of the state of the front surface layer or the back surface layer when the sheet starts to expand. A sample having a volume expansion ratio of 2 times or more at a temperature lower by 10 ° C. (230 ° C.) than the expansion start temperature of the heat-expandable graphite used was evaluated as ◯, and a sample having a volume expansion ratio of less than 2 was evaluated as x.
The thermal expansion start temperature of the thermally expandable graphite was determined by weighing 2 g of flakes, placing them in a 10 mmφ glass container, leveling them, placing them in an electric furnace set at a constant temperature, taking them out after 20 minutes, By measuring the thickness with calipers, the temperature was set in increments of 10 ° C., and the lowest temperature at which the volume expansion ratio was 1.5 times or more was defined as the expansion start temperature.

(2) Thermal expansion of the heat-insulating reinforcing layer and the shape-retaining expansion layer In the electric furnace set to 600 ° C., the heat-insulating reinforcing layer or the shape-retaining expanding layer cut to a size of 60 × 60 mm has an inner dimension of 60. It was inserted into a SUS metal frame having a size of 60 × 80 (H) mm, heated for 30 minutes, and then taken out. The expansion ratio of the combustion residue was calculated by the following method.
Expansion ratio during heating (times) = (thickness after heating) / (thickness before heating)
The state of heating at 600 ° C in the electric furnace is a simple reproduction of the state of the surface layer or back surface layer after the fire resistance test, so it is a guideline to form a heat insulation layer with this degree of expansion in an actual fire. Is the value.

(3) The shape of the combustion residue was cut into a size of 25 × 25 mm, placed in an aluminum pan, put in an electric furnace set at 250 ° C., heated for 20 minutes, and then taken out. The state of this combustion residue was visually observed, and the case where it was flaky was evaluated as ◯, and the case where a void was formed was evaluated as ×.

(4) Shape retention of shape-retaining expanded layer In an electric furnace set to 600 ° C., the shape-retainable expanded layer cut to a size of 60 × 60 mm has an inner dimension of 60 × 60 × 80 (H) mm. It was inserted into a SUS metal frame, heated for 30 minutes, and then taken out. This combustion residue was subjected to the test. The state of 600 ° C. electric furnace heating is a simple reproduction of the state of the surface layer after the fire resistance test.
Using a compression tester (manufactured by Kato Tech Co., Ltd., finger feeling tester), a combustion residue compression test was performed at a speed of 0.1 cm / sec using an indenter having a cross-sectional area diameter of 0.25 cm ² , and the load-compression curve was broken. The maximum point showing was taken as the residue hardness (load at break) (kgf / cm ² ). It can be said that the larger the residue hardness, the stronger the combustion residue and the higher the shape retention.
The case where the residue hardness was 0.1 kgf / cm ² or more was evaluated as ◯, and the case where it was less than 0.1 kgf / cm ² was evaluated as x.

(5) Fire resistance test In the embodiment shown in FIG. 1, the obtained steel fireproof sheet for steel frame was installed on a 50 mm-thick calcium silicate plate surface (size 400 mm × 200 mm × 8 mm × 13 mm, length 1200 mm) ) Was used as a test specimen. In addition, the steel frame is coated so that the heat-insulating reinforcing layer side is on the steel side and the shape-retaining expansion layer side is on the surface side, and the joint portion of the coated fireproof sheet for steel frame is treated by the joint treatment method suggested in Table 2 Went.
The prepared specimen is subjected to a fire resistance test for 2 hours by a method based on the test method of ISO 834, the average temperature of the surface of the H steel beam is measured, and it is 550 ° C. or less, which is a criterion for pass / fail judgment in the loading heating test The case where it exceeded (circle) and 550 degreeC was evaluated as x.

According to the present invention, it is possible to provide a fireproof coating sheet for a steel frame that is easy to construct and can impart a fireproof performance of 2 hours or more to a steel frame even with a thickness of 4 mm or less.

It is a schematic diagram which shows the construction example in the case of the edge part butt | injection of the covering fireproof sheet for steel frames of this invention, and aluminum tape construction. It is a schematic diagram which shows the construction example in the case of the overlap construction of the covering fireproof sheet for steel frames of this invention.

Explanation of symbols

1 Steel fireproof sheet 2 Steel frame 3 Aluminum tape

Claims (6)

A fireproof coating sheet for steel frames comprising a laminate in which a shape-retaining expansion layer and a heat-insulating reinforcing layer are laminated,
The shape-retaining expanded layer contains a thermoplastic resin and / or rubber, thermally expandable graphite, ammonium polyphosphate and calcium carbonate,
The heat-insulating reinforcing layer contains a thermoplastic resin and / or rubber, a liquid component, thermally expandable graphite, and a plate-like inorganic filler having an aspect ratio of 1.5 or more. . The steel heat-insulating layer according to claim 1, wherein the amount of the plate-like inorganic filler having an aspect ratio of 1.5 or more is 100 to 400 parts by weight with respect to 100 parts by weight of the resin component. Covered fireproof sheet. 3. The coated refractory sheet for steel frame according to claim 1 or 2, wherein the plate-like inorganic filler having an aspect ratio of 1.5 or more is talc or mica. 4. The coated refractory sheet for steel frames according to claim 1, wherein the shape-retaining expanded layer and / or the heat-insulating reinforcing layer has an aluminum base on one side or both sides. A method of coating a steel frame with the steel frame-coated fireproof sheet according to claim 1, wherein the heat-insulating reinforcing layer side is on the steel side and the shape-retaining expansion layer side is on the surface side. A steel frame coating method characterized by coating a steel frame with a coated refractory sheet. 6. The steel frame coating method according to claim 5, wherein the joint portion is abutted against the end, and an aluminum tape is affixed to the surface of the abutted portion.

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