JP2020045390A - Fire-resistant resin composition, and thermally expandable sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refractory resin composition having excellent long-term fire resistance and a heat-expandable sheet made of the refractory resin composition. The fire-resistant resin composition of the present invention is a fire-resistant resin composition containing a resin, a heat-expandable graphite, and a flame-retardant agent, and the decomposition temperature of the flame-retardant agent and the expansion of the heat-expandable graphite. The difference from the starting temperature (decomposition temperature of the flame retardant-expansion starting temperature of the heat-expandable graphite) is 100 ° C. or more. [Selection diagram] None

Description

  The present invention relates to a fire-resistant resin composition and a heat-expandable sheet comprising the fire-resistant resin composition.

In the construction field, fireproof materials are used for building materials such as fittings, columns, and wall materials for fire prevention. As the refractory material, a refractory sheet or the like in which a resin, a flame retardant, an inorganic filler, and the like are blended with thermally expandable graphite is used (for example, see Patent Document 1). Such a refractory material expands by heating, the combustion residue forms a refractory heat insulating layer, and exhibits refractory heat insulating performance.
The required performance of refractory materials differs depending on the application. Generally, fireproof equipment such as sashes and doors requires fire resistance of about 20 minutes, and when used for columns, beams, walls, etc., has a length of about 45 to 180 minutes. Fire resistance over time is required.

JP 2017-141463 A

Conventional refractory materials containing heat-expandable graphite have good refractory performance in a relatively short time, but when exposed to a long-time flame, the heat-expandable graphite gradually becomes ash, thereby increasing its strength. There has been a problem that the fire resistance decreases.
Therefore, an object of the present invention is to provide a fire-resistant resin composition having excellent fire resistance for a long time, and a heat-expandable sheet made of the fire-resistant resin composition.

As a result of intensive studies to solve the above problems, the present inventors have found that, in a fire-resistant resin composition containing a resin, thermally expandable graphite, and a flame retardant, the decomposition temperature of the flame retardant contained in the fire-resistant resin composition It has been found that the above problem can be solved by adjusting the difference between the expansion start temperature of the heat-expandable graphite and the heat-expandable graphite to a certain value or more, and completed the present invention. That is, the present invention is as follows.
[1] A fire-resistant resin composition containing a resin, heat-expandable graphite, and a flame retardant, wherein a difference between a decomposition temperature of the flame retardant and an expansion start temperature of the heat-expandable graphite (decomposition temperature of the flame retardant) -A refractory resin composition characterized in that the expansion start temperature of the heat-expandable graphite is 100 ° C or higher.
[2] The fire-resistant resin composition according to the above [1], wherein the content of the flame retardant is 0.05 to 1 in mass ratio to the content of the thermally expandable graphite.
[3] The fire-resistant resin composition according to the above [1] or [2], wherein the flame retardant is at least one selected from the group consisting of a phosphorus-based flame retardant and a bromine-based flame retardant.
[4] The refractory resin composition according to any one of [1] to [3], further comprising an organic phosphorus compound other than the flame retardant.
[5] The refractory resin composition according to the above [4], wherein the organic phosphorus compound is a phosphate compound.
[6] The refractory resin composition according to any one of [1] to [5], further comprising an inorganic filler.
[7] The fire-resistant resin composition according to the above [6], which contains 10 to 200 parts by mass of an inorganic filler with respect to 100 parts by mass of the resin.
[8] The fire-resistant resin composition according to any one of [1] to [7], wherein the heat-expandable graphite is contained in an amount of 50 to 200 parts by mass based on 100 parts by mass of the resin.
[9] The fire-resistant resin composition according to any one of [1] to [8], wherein the resin is a polyvinyl chloride resin.
[10] A heat-expandable sheet comprising the refractory resin composition according to any one of [1] to [9].

  According to the present invention, it is possible to provide a fire-resistant resin composition having excellent fire resistance for a long time, and a heat-expandable sheet made of the fire-resistant resin composition.

[Fire resistant resin composition]
The refractory resin composition of the present invention contains a resin, heat-expandable graphite, and a flame retardant, and the difference between the decomposition temperature of the flame retardant and the expansion start temperature of the heat-expandable graphite (the decomposition temperature of the flame retardant- Expansion start temperature of the heat-expandable graphite) is 100 ° C. or more. In this specification, the difference between the decomposition temperature of the flame retardant and the expansion start temperature of the thermally expandable graphite is a value obtained by subtracting the expansion start temperature of the thermally expandable graphite from the decomposition temperature of the flame retardant.
The reason why the fire-resistant resin composition of the present invention is excellent in fire resistance for a long time is not clear, but is presumed as follows. The heat-expandable graphite contained in the refractory resin composition expands at a temperature equal to or higher than the expansion start temperature to form an expanded heat insulating layer. If the flame-retardant is decomposed in a state where the heat-expandable graphite does not expand sufficiently, the uniformity of the flame-retardant properties on the surface of the expanded heat-insulating layer cannot be maintained, and the shape-retaining property of the expanded heat-insulating layer deteriorates with time. Worse. On the other hand, if the decomposition temperature of the flame retardant is sufficiently higher than the expansion start temperature of the heat-expandable graphite, the flame-retardant decomposes after the heat-expandable graphite expands sufficiently. A uniform flame-retardant layer is formed around the layer surface. As a result, it is considered that the shape of the expanded heat insulating layer is easily maintained for a long time, and the fire resistance is improved.

  In the refractory resin composition of the present invention, the difference between the decomposition temperature of the flame retardant and the expansion start temperature of the heat-expandable graphite is 100 ° C. or more. When the difference between the decomposition temperature of the flame retardant and the expansion start temperature of the heat-expandable graphite is less than 100 ° C., the fire resistance of the fire-resistant resin composition decreases. From the viewpoint of improving the fire resistance of the fire-resistant resin composition, the difference between the decomposition temperature of the flame retardant and the expansion start temperature of the heat-expandable graphite is preferably 120 ° C or more, more preferably 140 ° C or more, More preferably, the temperature is 200 ° C. or higher. Further, from the viewpoint that the flame retardant is appropriately decomposed at the time of combustion and the flame retardant effect is exhibited, the difference between the decomposition temperature of the flame retardant and the expansion temperature of the heat-expandable graphite is preferably 500 ° C or less, and 400 ° C or less. Is more preferable.

As the decomposition temperature of the flame retardant, the temperature when the mass of the flame retardant is reduced by 10% is measured by differential thermal-thermogravimetric simultaneous measurement (TG-DTA), and this is defined as the decomposition temperature.
The expansion start temperature of the heat-expandable graphite is measured by a temperature adjustment function and a device that measures the force in the normal direction by raising the temperature of the heat-expandable graphite at a constant temperature and measuring the temperature at which the force in the normal direction rises. Can be measured. The measuring device is not limited as long as it can control the measuring temperature and can measure the stress in the normal direction. For example, a rheometer can be used.

(Flame retardants)
The flame retardant contained in the refractory resin composition of the present invention is appropriately selected from those having a difference between the decomposition temperature of the flame retardant and the expansion start temperature of the heat-expandable graphite of 100 ° C. or more. Can be. That is, it can be appropriately selected in consideration of the expansion start temperature of the thermally expandable graphite to be used.
The flame retardant can be selected from those having a decomposition temperature of preferably from 250 to 600 ° C, more preferably from 320 to 550 ° C, and still more preferably from 350 to 500 ° C. When the decomposition temperature of the flame retardant is at least these lower limits, the difference from the expansion start temperature of the heat-expandable graphite can be easily made to be a certain value or more, and when the decomposition temperature is at or below these upper limits, the flame retardant is decomposed. , It is easy to improve fire resistance.

  The type of the flame retardant is not particularly limited as long as the difference between the decomposition temperature of the flame retardant and the expansion start temperature of the heat-expandable graphite is 100 ° C. or more, and a phosphorus-based flame retardant, a nitrogen-containing flame retardant, What is necessary is just to select suitably from halogen flame retardants, such as a bromine flame retardant and a chlorine flame retardant. From the viewpoint of further improving fire resistance, it is preferable to use at least one selected from the group consisting of phosphorus-based flame retardants and bromine-based flame retardants as the flame retardant.

The phosphorus-based flame retardant is not particularly limited as long as the difference from the expansion temperature of the heat-expandable graphite used is 100 ° C. or more. Examples thereof include ammonium polyphosphate, melamine polyphosphate, melamine polymetaphosphate, and polyphosphorus. Melamine acid, melam, melem, phosphorus spiro compounds, phosphazene compounds and the like. Among these, phosphazene-based compounds, phosphorus-based spiro compounds, and the like are more preferable from the viewpoint of having a high decomposition temperature and easily adjusting the difference from the expansion temperature of the heat-expandable graphite to a certain level or more.
As the phosphorus-based flame retardant, any of an organic phosphorus-based flame retardant and an inorganic phosphorus-based flame retardant can be used, but it is preferable to use an organic phosphorus-based flame retardant.
A phosphazene-based compound is an organic compound having a -P = N- bond in a molecule. As the phosphazene-based compound, a compound represented by the following general formula (1) is preferable because it has a relatively high decomposition temperature.

In the above formula (1), R _{1 to} R ₆ are each independently an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, an amino group, and a halogen atom. Indicates one of
Examples of such a phosphazene-based compound include “SPB-100” commercially available from Otsuka Chemical Co., Ltd.

The phosphorus-based spiro compound is not particularly limited as long as it is a spiro compound having a phosphorus atom. Note that a spiro compound is a compound having a structure in which two cyclic compounds share one carbon, and a spiro compound having a phosphorus atom means that at least one of the elements constituting the two cyclic compounds is a phosphorus atom. A certain compound.
As the phosphorus-based spiro compound, for example, it is preferable to use a compound having a structural unit represented by the following formula (2) in the molecule.

The brominated flame retardant is not particularly limited as long as the difference between the decomposition temperature of the flame retardant and the expansion temperature of the heat-expandable graphite used is 100 ° C. or more. It may be a flame retardant or an aromatic bromine-based flame retardant. Examples of the aliphatic bromine-based flame retardant include tetrabromocyclooctane, hexabromocyclododecane, trisdibromopropyl phosphate, and the like. Examples of the aromatic bromine-based flame retardant include decabromodiphenyl oxide, octabromodiphenyl oxide, a brominated bisphenol A-based flame retardant, and a brominated bisphenol S-based flame retardant. Among these, aromatic flame retardants are preferred, and brominated bisphenol A flame retardants are more preferred, from the viewpoint of having a high decomposition temperature and easily adjusting the difference from the expansion temperature of the heat-expandable graphite to a certain level or more. .
As the brominated bisphenol A-based flame retardant, any compound having a structural unit derived from bisphenol A in which at least one hydrogen atom is substituted with a bromine atom may be used. The brominated bisphenol A-based flame retardant may have one structural unit, but is preferably a brominated polycarbonate having a plurality of structural units.
As the brominated bisphenol A-based flame retardant, it is preferable to use a compound having a structural unit represented by the following formula (3) from the viewpoint of having a relatively high decomposition temperature.

Among the compounds having the structural unit represented by the above formula (3), from the viewpoint of having a high decomposition temperature and easily adjusting the difference from the expansion temperature of the heat-expandable graphite to a certain value or more, particularly the following formula (4) It is preferable to use a compound represented by the following formula (5).



In the above formulas (4) and (5), n is 1 to 50, but n is preferably 1 to 30, and more preferably 5 to 20.

Examples of such a brominated bisphenol A-based flame retardant include Fire Guard 7000, Fire Guard 7500, and Fire Guard 8500 commercially available from Teijin Limited.
The above-mentioned flame retardants may be used alone or in combination of two or more.

  The content of the flame retardant is preferably 0.05 to 1, more preferably 0.20 to 0.95, and more preferably 0.40 to 0.95 by mass ratio to the content of the heat-expandable graphite. ０．９0.90, more preferably 0.60 to 0.90. By adjusting the content of the flame retardant as described above, the shape of the expanded heat insulating layer formed by expansion of the heat-expandable graphite can be easily maintained, and the fire resistance of the fire-resistant resin composition and the heat-expandable sheet made thereof can be improved. The property is easily improved.

  The content of the flame retardant in the fire-resistant resin composition is not particularly limited. For example, the flame retardant is preferably 5 to 300 parts by mass, and more preferably 20 to 200 parts by mass with respect to 100 parts by mass of the resin. More preferably, it is still more preferably 40 to 150 parts by mass. By setting the content of the flame retardant to 5 parts by mass or more, the fire resistance of the fire-resistant resin composition is improved, and by setting the content to 300 parts by mass or less, the workability of the fire-resistant resin composition is easily improved. .

(Thermally expandable graphite)
The refractory resin composition of the present invention contains thermally expandable graphite. The heat-expandable graphite may be appropriately selected from those satisfying the requirement that the difference between the decomposition temperature of the flame retardant and the expansion start temperature of the heat-expandable graphite is 100 ° C. or more.
The heat-expandable graphite is a conventionally known substance which expands when heated, and is obtained by subjecting raw material powders such as natural scale graphite, pyrolytic graphite, and quiche graphite to an acid treatment with a strong oxidizing agent to form a graphite intercalation compound. is there. Examples of the strong oxidizing agent include inorganic acids such as concentrated sulfuric acid, nitric acid and selenic acid, concentrated nitric acid, perchloric acid, perchlorate, permanganate, dichromate, hydrogen peroxide and the like. Thermally expandable graphite is a crystalline compound that maintains the layered structure of carbon.

  The heat-expandable graphite may be neutralized. That is, the heat-expandable graphite obtained by treating with a strong oxidizing agent or the like as described above may be further neutralized with ammonia, an aliphatic lower amine, an alkali metal compound, an alkaline earth metal compound, or the like.

  The expansion start temperature of the heat-expandable graphite is preferably from 150 to 350 ° C, more preferably from 170 to 300 ° C, and more preferably from 180 to 280, from the viewpoint that the difference from the decomposition temperature of the flame retardant is equal to or more than a certain value. It is more preferable that the temperature is ° C. When the heat-resistant resin composition is not less than these lower limits, it is easy to prevent unnecessary thermal expansion when the heat-resistant resin composition is formed into a heat-expandable sheet. Can be easily adjusted over a certain level.

  The particle size of the heat-expandable graphite is preferably from 20 to 200 mesh. If the particle size is 200 mesh or smaller, the degree of expansion of the graphite is sufficient to obtain an expanded heat insulating layer, and if the particle size is 20 mesh or larger, the dispersibility at the time of blending with the resin is good, and the physical properties are poor. Good. The particle size is measured by a sieve according to JISZ8801-1.

  The content of the heat-expandable graphite is not particularly limited, but is preferably 50 to 200 parts by mass, more preferably 60 to 150 parts by mass, per 100 parts by mass of the resin. When the amount is 50 parts by mass or more, it becomes easy to obtain expansion suitable for preventing the passage of fire, and when the amount is 200 parts by mass or less, the processability of the refractory resin composition and the heat-expandable sheet comprising the same is reduced. Become good.

(resin)
The resin contained in the refractory resin composition of the present invention includes a thermoplastic resin, a thermosetting resin, an elastomer, a rubber, and a combination thereof.
Examples of the thermoplastic resin include a polyolefin resin such as a polypropylene resin, a polyethylene resin, a poly (1-) butene resin, a polypentene resin, a polyester resin such as a polyethylene terephthalate, a polystyrene resin, an acrylonitrile-butadiene-styrene (ABS) resin, and an ethylene resin. Synthetic resins such as vinyl acetate copolymer (EVA), polycarbonate resin, polyphenylene ether resin, (meth) acrylic resin, polyamide resin, polyvinyl chloride resin (PVC), novolak resin, polyurethane resin, and polyisobutylene.

  Examples of the thermosetting resin include synthetic resins such as polyurethane, polyisocyanate, polyisocyanurate, phenol resin, epoxy resin, urea resin, melamine resin, unsaturated polyester resin, and polyimide.

  Examples of the elastomer include an olefin-based elastomer, a styrene-based elastomer, an ester-based elastomer, an amide-based elastomer, and a vinyl chloride-based elastomer.

Examples of the rubber include natural rubber, isoprene rubber, butadiene rubber, 1,2-polybutadiene rubber, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, butyl rubber, chlorinated butyl rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber (EPDM) And chlorosulfonated polyethylene, acrylic rubber, epichlorohydrin rubber, multi-vulcanized rubber, non-vulcanized rubber, silicone rubber, fluoro rubber, urethane rubber and other rubbers.
Among these, silicone rubber, fluororubber and the like are preferable, and silicone rubber is more preferable, from the viewpoint of reducing the proportion of carbon contained from the viewpoint of fire resistance.

Among the above thermoplastic resins, thermosetting resins, elastomers, and rubbers, a thermoplastic resin is particularly preferable from the viewpoint of improving workability. The thermoplastic resin may be used in combination with at least one of a thermosetting resin, an elastomer, and rubber, or may be used alone.
Further, among the thermoplastic resins, at least one selected from a polyethylene resin, an ethylene-vinyl acetate copolymer, (EVA), and a polyvinyl chloride resin is preferable. Among them, polyvinyl chloride resin is more preferable from the viewpoint of reducing the proportion of carbon contained in view of fire resistance.

The polyvinyl chloride resin may be a vinyl chloride homopolymer or a vinyl chloride copolymer. The vinyl chloride copolymer is a copolymer of vinyl chloride and a monomer having an unsaturated bond copolymerizable with vinyl chloride, and contains 50% by mass or more of a structural unit derived from vinyl chloride.
As the monomer having an unsaturated bond copolymerizable with vinyl chloride, for example, vinyl acetate, vinyl esters such as vinyl propionate, acrylic acid, methacrylic acid, acrylic acid esters such as methyl acrylate, ethyl acrylate, Examples include methacrylates such as methyl methacrylate and ethyl methacrylate, olefins such as ethylene and propylene, aromatic vinyls such as acrylonitrile and styrene, and vinylidene chloride.
Further, the polyvinyl chloride resin may be a polychlorinated vinyl chloride resin. The polychlorinated vinyl chloride resin is a polychlorinated vinyl chloride resin obtained by chlorinating a vinyl chloride homopolymer, a vinyl chloride copolymer, or the like.
As the polyvinyl chloride resin, one kind may be used alone, or two or more kinds may be used in combination.

  The average degree of polymerization of the polyvinyl chloride resin is not particularly limited, but is preferably from 400 to 3,000. By setting the average degree of polymerization to 400 or more, the mechanical properties of the thermally expandable sheet are improved. Further, by setting the average degree of polymerization to 3000 or less, the processability is easily improved. From these viewpoints, the average degree of polymerization is more preferably 700 to 1500. The average polymerization degree was measured according to JIS K6720-2.

  The total content of the flame retardant, the heat-expandable graphite, and the resin is preferably 20% by mass or more, more preferably 40% by mass or more, and preferably 50% by mass, based on the total amount of the refractory resin composition. %, More preferably at most 95% by mass, more preferably at most 90% by mass, even more preferably at most 85% by mass.

(Organic phosphorus compounds other than flame retardants)
The refractory resin composition of the present invention preferably contains an organic phosphorus compound other than the flame retardant as a dispersant. By containing the organic phosphorus compound, the fire resistance of the fire-resistant resin composition is improved. This is considered to be because the inclusion of the organophosphorus compound allows the flame retardant to be appropriately arranged around the heat-expandable graphite, and makes it easier to maintain the shape of the expanded heat-insulating layer, which is the expanded residue. .
Among the organic phosphorus compounds, phosphate ester compounds are preferable from the viewpoint of further improving the fire resistance of the fire resistant resin composition.

  Examples of the phosphate compound include trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, octyl diphenyl phosphate, tributoxyethyl phosphate, trichloroethyl phosphate, tris (2-chloropropyl) phosphate, and tris (2,3-dichloropropyl). ) Phosphate, tris (2,3-dibromopropyl) phosphate, tris (bromochloropropyl) phosphate, bis (2,3-dibromopropyl) -2,3-dichloropropylphosphate, bis (chloropropyl) monooctylphosphate, tris (2-ethylhexyl) phosphate, triphenyl phosphate, tricresyl phosphate (TCP), trixylenyl phosphate, cresyl dif Niruhosufeto include xylenyl diphenyl phosphate and the like. Among these, trixylenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, and tricresyl phosphate (TCP) are particularly preferable.

  The content of the organic phosphorus compound is not particularly limited, but from the viewpoint of increasing the dispersibility of the flame retardant and further improving the fire resistance of the fire-resistant resin composition, 0.1 to 100 parts by mass of the resin. The amount is preferably 20 parts by mass, more preferably 1 to 15 parts by mass, and even more preferably 2 to 10 parts by mass.

(Inorganic filler)
The refractory resin composition of the present invention preferably contains an inorganic filler. When the inorganic filler is heated to form the expanded heat insulating layer, the inorganic filler acts as an aggregate to improve the strength of the expanded heat insulating layer while increasing the heat capacity and suppressing heat transfer. The inorganic filler is not particularly limited, for example, alumina, zinc oxide, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, metal oxides such as ferrite, calcium hydroxide, magnesium hydroxide, Metal hydroxides such as aluminum hydroxide and hydrotalcite, basic magnesium carbonate, calcium carbonate, magnesium carbonate, zinc carbonate, strontium carbonate, metal carbonates such as barium carbonate, calcium sulfate, gypsum fiber, calcium silicate, etc. Calcium salt, silica, diatomaceous earth, dawsonite, barium sulfate, talc, clay, mica, montmorillonite, bentonite, activated clay, sepiolite, imogolite, sericite, glass fiber, glass beads, silica balloon, aluminum nitride, boron nitride, ketone nitride Element, carbon black, graphite, carbon fiber, carbon balloon, various metal powders, potassium titanate, magnesium sulfate, lead zirconate titanate, aluminum borate, molybdenum sulfide, silicon carbide, stainless steel fiber, zinc borate, various magnetic powders, Slag fiber, fly ash, and the like are included. One kind of the inorganic filler may be used alone, or two or more kinds may be used in combination.
Among these, at least one selected from metal oxides and metal carbonates is preferable.

The particle size of the inorganic filler is preferably from 0.5 to 100 μm, more preferably from 1 to 50 μm. By setting the lower limit or more, it is possible to prevent the occurrence of secondary aggregation and improve the dispersibility. Further, when the value is equal to or more than the lower limit, the viscosity of the refractory resin composition can be reduced, and the processability is easily improved. In addition, when the content is equal to or less than the upper limit, the surface property and mechanical performance of the heat-expandable sheet formed of the fire-resistant resin composition are improved.
The particle size of the inorganic filler is determined by observing the SEM (scanning electron microscope image) to determine the particle size distribution. The particle size is determined as the average particle size.

  The content of the inorganic filler is preferably from 10 to 200 parts by mass, more preferably from 15 to 150 parts by mass, based on 100 parts by mass of the resin. When the content of the inorganic filler is 10 parts by mass or more, the fire resistance of the fire-resistant resin composition is improved. When the amount is 200 parts by mass or less, workability is improved and mechanical properties are easily maintained.

(Plasticizer)
The refractory resin composition of the present invention may contain a plasticizer. By containing a plasticizer, the flexibility of a heat-expandable sheet or the like formed of the fire-resistant resin composition can be increased, and the workability can be easily improved. The plasticizer is suitable when a thermoplastic resin is used as the above-mentioned resin, and is particularly preferably used when a polyvinyl chloride resin is used.
As the plasticizer, a liquid component which becomes liquid at ordinary temperature (23 ° C.) and ordinary pressure (1 atm) is generally used.

Specific examples of the plasticizer include di-2-ethylhexyl phthalate (DOP), di-n-octyl phthalate, diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), diundecyl phthalate (DUP), and C10-C10. About 13 higher alcohols or phthalic acid ester-based plasticizers such as phthalic acid esters of mixed alcohols, di-2-ethylhexyl adipate (DOA), diisobutyl adipate (DIBA), dibutyl adipate (DBA), di-n-octyl adipate, Aliphatic ester plasticizers such as di-n-decyl adipate, diisodecyl adipate, di-2-ethylhexyl azelate, dibutyl sebacate and di-2-ethylhexyl sebacate; tri-2-ethylhexyl trimellitate (TOTM); Trimellitate plasticizers such as l-n-octyl trimellitate, tridecyl trimellitate, triisodecyl trimellitate, and di-n-octyl-n-decyl trimellitate; 2,3,3 '4,4'-biphenyltetracarboxylic acid tetraheptyl ester and other biphenyltetracarboxylic acid tetraalkylester plasticizers, polyester polymer plasticizers, epoxidized soybean oil, epoxidized linseed oil, epoxidized cottonseed oil, liquid epoxy resin, etc. Examples include epoxy plasticizers, chlorinated paraffins, and chlorinated fatty acid esters such as alkyl pentachloride stearic acid.
These plasticizers may be used alone, or two or more plasticizers may be used in combination.
Of the above plasticizers, phthalic acid plasticizers are preferred in terms of flame retardancy and economical efficiency. The phthalic acid-based plasticizer may be used alone or in combination with a phosphate ester-based plasticizer.

  The content of the plasticizer is preferably 30 to 130 parts by mass, more preferably 40 to 120 parts by mass, and still more preferably 50 to 100 parts by mass with respect to 100 parts by mass of the resin. When the content of the plasticizer is equal to or more than these lower limits, the flexibility of a sheet formed from the fire-resistant resin composition can be increased, and the workability of the sheet can be improved. The sheet can be prevented from becoming too soft.

  The refractory resin composition of the present invention may contain other components other than the above. Other components include phenol-based, amine-based, sulfur-based antioxidants, metal harm prevention agents, antistatic agents, stabilizers, cross-linking agents, lubricants, softeners, pigments, etc. as long as the physical properties are not impaired. Of various additives.

[Thermal expandable sheet]
The heat-expandable sheet of the present invention comprises the above-described fire-resistant resin composition.
The heat-expandable sheet expands the heat-expandable graphite by heating to form an expanded heat-insulating layer. The heat-expandable sheet is insulated by such an expansion heat-insulating layer when exposed to high temperatures such as during a fire, and functions as a fire-resistant material. For example, the expansion ratio of the thermally expandable sheet after heating at 600 ° C. for 120 minutes becomes 3 to 50 times. The expansion ratio is calculated as (thickness of test piece after heating) / (thickness of test piece before heating) of the test piece of the heat-expandable sheet.

  Although the thickness of the heat-expandable sheet is not particularly limited, it is preferably from 0.2 to 10 mm, more preferably from 0.5 to 3.0 mm, from the viewpoint of fire resistance and handleability.

(Production method of heat-expandable sheet)
The heat-expandable sheet of the present invention can be manufactured, for example, as follows.
First, a predetermined amount of a resin, thermally expandable graphite, a flame retardant, and other additives to be blended as necessary are kneaded with a kneading machine such as a kneading roll to obtain a fire-resistant resin composition.
Next, when the resin is a thermoplastic resin, rubber, an elastomer, or a combination thereof, the obtained refractory resin composition is formed into a sheet by a known molding method such as, for example, press molding, calender molding, or extrusion molding. To obtain a thermally expandable sheet.
When the resin contains a thermosetting resin, the obtained refractory resin composition may be heated and pressed by, for example, press molding to form a sheet and thermally cure to obtain a thermally expandable sheet.

(Laminated sheet)
The heat-expandable sheet of the present invention may constitute a laminated sheet by laminating other sheet members and pressure-sensitive adhesive layers. The laminated sheet includes, for example, a substrate and a thermally expandable sheet laminated on one or both sides of the substrate. The substrate is usually a woven or non-woven fabric. The fiber used for the woven or nonwoven fabric is not particularly limited, but a non-combustible material or a quasi-non-combustible material is preferable, for example, glass fiber, ceramic fiber, cellulose fiber, polyester fiber, carbon fiber, graphite fiber, thermosetting. And the like are preferred.
The laminated sheet can be obtained, for example, by molding the refractory resin composition into a sheet shape on a base material and, if necessary, thermally curing the refractory resin composition.

Further, the laminated sheet may include a thermally expandable sheet and an adhesive layer. The pressure-sensitive adhesive layer may be laminated on one side or both sides of the heat-expandable sheet, for example.
Further, the laminated sheet may include a heat-expandable sheet, a base material, and an adhesive layer. Such a laminated sheet may be provided with a heat-expandable sheet on one surface of a substrate and an adhesive layer on the other surface, or a heat-expandable sheet and an adhesive on one surface of the substrate. The agent layers may be provided in this order. The pressure-sensitive adhesive layer can be formed, for example, by transferring a pressure-sensitive adhesive applied to release paper to a laminated sheet.

  The refractory resin composition of the present invention, a thermally expandable sheet and a laminated sheet made of the refractory resin composition can be used as refractory materials. These can be specifically used for detached houses, apartment houses, high-rise houses, high-rise buildings, commercial facilities, various facilities such as public facilities, various vehicles such as automobiles and trains, ships, aircraft, etc. Of these, it is preferable to use them for buildings. As a building, specifically, it can be used for walls, beams, columns, floors, bricks, roofs, plate materials, windows, shojis, doors, doors, doors, brans, transoms, wiring, piping, etc. It is not limited to these. Since the fire-resistant resin composition of the present invention is excellent in fire resistance for a long time, it is particularly preferably used for specific fire prevention equipment, walls, beams, columns, floors and the like.

  Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited thereto.

[Evaluation methods]
The decomposition temperature of the flame retardant and the expansion start temperature of the heat-expandable graphite were measured as follows.
(Decomposition temperature of flame retardant)
The measurement was performed based on JIS 7120. A 10 mg sample of the flame retardant was taken as a sample, and a nitrogen gas amount of 75 ml / min and a heating rate were measured by a differential thermal-thermogravimetric simultaneous measuring device (manufactured by Hitachi High-Tech Science Co., Ltd., “Differential thermogravimetric simultaneous measuring device STA7200”). The temperature at which the mass of the flame retardant was reduced by 10% under the conditions of 10 ° C / min and the measurement temperature of 100 to 800 ° C was defined as the decomposition temperature.
(Expansion start temperature of thermally expandable graphite)
100 mg of the heat-expandable graphite was sampled and used as a sample, and the temperature was increased at a heating temperature of 10 ° C./min using a rheometer (“Discovery HR2”, manufactured by TA Instruments), and the force in the normal direction was increased. Was measured and this was taken as the expansion start temperature.

With respect to the heat-expandable sheets obtained in Examples and Comparative Examples, expansion ratios and residual hardness were measured. The residual hardness represents the hardness of the test specimen after heating, and the higher the value, the better the fire resistance.
(Expansion magnification)
A test piece (length 100 mm, width 100 mm, thickness 1.6 mm) prepared from the obtained heat-expandable sheets of Examples and Comparative Examples was placed on the bottom surface of a stainless steel holder (101 mm square × 80 mm height). , And heated at 600 ° C. for 30 minutes. After that, the height (the highest part) of the specimen was measured for its width, height and thickness, and it was expanded according to ((thickness of specimen after heating) / (thickness of specimen before heating)). The magnification was calculated.
(Residue hardness)
The heated test piece whose expansion ratio was measured was supplied to a compression tester ("Finger Filing Tester", manufactured by Kato Tech Co., Ltd.), and was compressed at a speed of 0.1 cm / sec with a 3-point indenter having a diameter of 1 mm. The maximum stress up to 10 mm compression from the upper surface was measured, and the compressive strength of the test specimen after combustion was measured.
(Fire resistance)
A 50 mm calcium silicate plate manufactured by A & A Material Co., Ltd. was cut into 1180 mm × 1180 mm in a refractory furnace, and a joint having a width of 20 mm and a length of 200 mm was formed at the center. A thermally expandable sheet having a thickness of 1.6 mm and a size of 10 mm × 200 mm was stuck to the joint side face with an iron needle using a stable gun. The iron needle was fixed at three positions, that is, the upper and lower ends and the center thereof, to prepare a test body. This specimen was subjected to a fire resistance test for 120 minutes at a temperature adjusted according to the standard heating curve of ISO834 and at a furnace pressure of 20 Pa. The specimen during the fire resistance test was observed, and a specimen in which the residue of the expanding material stuck on the specimen did not collapse for 120 minutes was marked as Δ, and a specimen which collapsed and penetrated in the furnace was rated X.

(Examples 1 to 14, Comparative Example 1)
With the composition shown in Table 1 below, a resin, a flame retardant, thermally expandable graphite, an inorganic filler, a plasticizer, and a dispersant were put into a roll and kneaded at 130 ° C. for 5 minutes to obtain a fire-resistant resin composition. Was. The obtained refractory resin composition was press-molded at 130 ° C. for 3 minutes by press molding to obtain a 1.6 mm-thick thermally expandable sheet. The components used in each of the examples and comparative examples are as follows.
(Examples 15 and 16)
A main component of a liquid silicone rubber ("ELASTOSHIL M4600" manufactured by Asahi Kasei Wacker Silicone Co., Ltd.) and a curing agent were mixed at a ratio of 10: 1 (mass ratio) and cured at 23 ° C. for 12 hours to obtain a resin. With the composition shown in Table 1 below, the above resin, flame retardant, thermally expandable graphite, inorganic filler, plasticizer, and dispersant were blended in a cup, and stirred with a planetary stirrer. The obtained mixture was pressed at 23 ° C., molded into a 1.6 mm sheet, and allowed to stand at 23 ° C. for 12 hours to obtain a 1.6 mm thick thermally expandable sheet.

(1) Resin / PVC: polyvinyl chloride resin, manufactured by Shin-Etsu Chemical Co., Ltd., trade name “TK-1000”, average degree of polymerization 1030
・ Silicone rubber: Liquid silicone rubber, manufactured by Asahi Kasei Wacker Silicone Co., Ltd., trade name “ELASTOSIL M4600”
(2) Flame retardant / phosphazene compound: trade name “SPB-100” manufactured by Otsuka Chemical Co., Ltd. Decomposition temperature 380 ° C
-Organophosphorus flame retardant: manufactured by Teijin Limited, trade name "FCX-210" Decomposition temperature 360 ° C
-Brominated bisphenol A flame retardant: "Fireguard 7000" (trade name, manufactured by Teijin Limited) Decomposition temperature 451 ° C
-Brominated bisphenol A flame retardant: manufactured by Teijin Limited, trade name "Fireguard 7500" Decomposition temperature 454 ° C
-Brominated bisphenol A flame retardant: manufactured by Teijin Limited, trade name "Fireguard 8500" Decomposition temperature 458 ° C
-Ammonium polyphosphate: Clariant Japan K.K., trade name "AP422" Decomposition temperature 300 ° C
(3) Thermal expansive graphite / thermal expansive graphite: trade name “CA-60N” manufactured by Air Water Co., Ltd.
-Thermal expandable graphite: ADT Co., Ltd., trade name "ADT501" Expansion start temperature 150 ° C
(4) Inorganic filler calcium carbonate: trade name “BF300” manufactured by Shiraishi Calcium Co., Ltd.
・ Zinc oxide: manufactured by Sakai Chemical Industry Co., Ltd., trade name “One type of zinc oxide”
(5) Plasticizer / DOP: di-2-ethylhexyl phthalate, DOP manufactured by J-PLUS Co., Ltd.
(6) Dispersant / TCP: tricresyl phosphate, TCP manufactured by Daihachi Chemical Co., Ltd.

  As shown in the above examples, since the difference between the decomposition temperature of the flame retardant and the expansion start temperature of the heat-expandable graphite of the heat-expandable sheet made of the fire-resistant resin composition of the present invention is 100 ° C. or more, It was found that the value of the hardness of the residue after heating at 600 ° C. for 120 minutes was high, and the fire resistance was excellent for a long time. On the other hand, since the difference between the decomposition temperature of the flame retardant and the expansion start temperature of the heat-expandable graphite is less than 100 ° C. in the heat-expandable sheet of Comparative Example, the value of the residual hardness is low, It was found that the fire resistance was poor.

Claims (10)

  A fire-resistant resin composition containing a resin, heat-expandable graphite, and a flame retardant, wherein the difference between the decomposition temperature of the flame retardant and the expansion start temperature of the heat-expandable graphite (decomposition temperature of flame retardant-thermal expansion) A refractory resin composition having an expansion start temperature of the exfoliated graphite of 100 ° C. or higher.   The refractory resin composition according to claim 1, wherein the content of the flame retardant is 0.05 to 1 in mass ratio to the content of the thermally expandable graphite.   The fire-resistant resin composition according to claim 1 or 2, wherein the flame retardant is at least one selected from the group consisting of a phosphorus-based flame retardant and a bromine-based flame retardant.   The refractory resin composition according to any one of claims 1 to 3, further comprising an organic phosphorus compound other than the flame retardant.   The refractory resin composition according to claim 4, wherein the organic phosphorus compound is a phosphate compound.   The refractory resin composition according to claim 1, further comprising an inorganic filler.   The fire-resistant resin composition according to claim 6, wherein the composition contains 10 to 200 parts by mass of an inorganic filler based on 100 parts by mass of the resin.   The refractory resin composition according to any one of claims 1 to 7, wherein the thermally expandable graphite is contained in an amount of 50 to 200 parts by mass with respect to 100 parts by mass of the resin.   The fire-resistant resin composition according to any one of claims 1 to 8, wherein the resin is a polyvinyl chloride resin.   A heat-expandable sheet comprising the refractory resin composition according to claim 1.