JP2024051159A - Fire-resistant resin composition, fire-resistant sheet and fitting - Google Patents

Abstract

To provide a fire-resistant resin composition which enables manufacture of a fire-resistant sheet that can exhibit excellent fire resistance and cold resistance.SOLUTION: A fire-resistant resin composition contains a matrix resin, a thermally expandable graphite, and an inorganic filler. A content of the total of the thermally expandable graphite and the inorganic filler is 35 mass% or more, the matrix resin contains a rubber component, and a content of the rubber component is 15 mass% or more based on the total amount of the matrix resin.SELECTED DRAWING: None

Description

The present invention relates to a fire-resistant resin composition containing thermally expandable graphite, a fire-resistant sheet made of the fire-resistant resin composition, and fittings equipped with the fire-resistant sheet.

In the field of construction, fireproof materials are used in building materials such as fittings, pillars, and wall materials for fire prevention. Fireproof sheets made of resin mixed with inorganic fillers and thermally expandable graphite are used as fireproof materials (see, for example, Patent Document 1). Such fireproof sheets expand when heated, and the combustion residue forms a fireproof insulation layer, thereby exhibiting fireproof insulation performance.
A fire-resistant sheet containing thermally expandable graphite is placed, for example, in the gap between fittings such as doors and windows installed in openings in a building and the frames surrounding them, such as door frames and window frames; in the event of a fire, the sheet expands in the thickness direction, closing the gap between the fittings and the frames and preventing the fire from spreading.

JP 2017-141463 A

In general, fireproof sheets need to contain many inorganic compounds such as thermally expandable graphite and inorganic fillers to exhibit fire resistance. Therefore, the fireproof sheets tend to become brittle, and this tendency is particularly pronounced when used in cold regions, and the fireproof sheets are prone to problems such as breaking or cracking on the surface when attached to fittings, making them difficult to handle. In particular, the above-mentioned problems are likely to occur in the case of long fireproof sheets, and improvements have been required.
On the other hand, in order to improve the brittleness of the fire-resistant sheet, it is possible to reduce the content of the above-mentioned inorganic compounds, but in this case, the fire resistance will decrease due to a decrease in the strength of the thermal expansion residue, etc.
Therefore, an object of the present invention is to provide a fire-resistant resin composition which can be used to form a fire-resistant sheet having excellent cold resistance due to improved brittleness and also excellent fire resistance due to the high strength of the thermally expandable residue.

As a result of intensive research to solve the above problems, the present inventors have found that the above problems can be solved by setting the total amount of the thermally expandable graphite and the inorganic filler to a certain amount or more in a fire-resistant resin composition containing a matrix resin, thermally expandable graphite, and an inorganic filler, and setting the amount of the rubber component in the matrix resin to a certain amount or more, thereby completing the present invention. That is, the present invention is as follows: [1] to [8].

[1] A fire-resistant resin composition comprising a matrix resin, thermally expandable graphite, and an inorganic filler, wherein the total content of the thermally expandable graphite and the inorganic filler is 35 mass% or more, and the matrix resin contains a rubber component, wherein the content of the rubber component is 15 mass% or more based on the total amount of the matrix resin.
[2] The fire-resistant resin composition according to the above [1], wherein the rubber component contains a rubber having an unsaturated bond.
[3] The fire-resistant resin composition according to the above [1] or [2], wherein the matrix resin contains a resin component containing at least one of a halogen atom, or a structural unit derived from styrene or vinyl acetate.
[4] The fire-resistant resin composition according to any one of the above [1] to [3], wherein the inorganic filler contains an inorganic filler A having a specific gravity of 2.5 or more.
[5] The fire-resistant resin composition according to any one of the above [1] to [4], which does not contain a phosphorus component.
[6] A fire-resistant sheet comprising the fire-resistant resin composition according to any one of [1] to [5] above.
[7] The fire-resistant sheet according to [6] above, which is a long product having a length of 1 m or more.
[8] A fixture equipped with the fireproof sheet described in [6] or [7] above.

The present invention provides a fire-resistant resin composition that can be used to produce a fire-resistant sheet with excellent cold resistance and fire resistance, and a fire-resistant sheet made from the same.

[Fire-resistant resin composition]
The fire-resistant resin composition of the present invention contains a matrix resin, thermally expandable graphite, and an inorganic filler, the total content of the thermally expandable graphite and the inorganic filler being 35 mass% or more, and the matrix resin contains a rubber component, the content of the rubber component being 15 mass% or more based on the total amount of the matrix resin.

<Matrix resin>
The fire-resistant resin composition of the present invention contains a matrix resin, and thermally expandable graphite and an inorganic filler are dispersed in the matrix resin.
The matrix resin contains a rubber component, and the content of the rubber component is 15% by mass or more based on the total amount of the matrix resin. If the content of the rubber component is less than 15% by mass, the fire-resistant sheet formed from the fire-resistant resin composition becomes brittle, and when used in cold regions, problems such as the sheet breaking or cracking on the surface tend to occur, resulting in poor cold resistance. From the viewpoint of improving cold resistance, the content of the rubber component is preferably 25% by mass or more, more preferably 50% by mass or more, even more preferably 80% by mass or more, and even more preferably 100% by mass based on the total amount of the matrix resin.

The rubber component preferably contains a rubber having an unsaturated bond. By containing a rubber having an unsaturated bond, the cold resistance and fire resistance of the fire-resistant sheet formed from the fire-resistant resin composition are improved. The reason for this is unclear, but is presumed to be as follows. By using a rubber having an unsaturated bond, the affinity between the rubber and the thermally expandable graphite is improved, which increases the dispersibility of the thermally expandable graphite in the fire-resistant sheet, thereby preventing the thermally expandable graphite from being unevenly distributed and making the fire-resistant sheet brittle, and improving the cold resistance. In addition, since the dispersibility of the thermally expandable graphite and the interfacial adhesion between the expandable graphite and the matrix resin are good, there are fewer voids between the thermally expandable graphite and the matrix resin in the sheet, and when burned, the resin char and the expandable graphite are firmly adhered to each other, and the strength of the thermally expandable residue is also increased, improving the fire resistance.

Here, the unsaturated bond is preferably a carbon-carbon unsaturated bond, more preferably a carbon-carbon double bond. Examples of rubbers having an unsaturated bond include diene rubbers and natural rubbers, which will be described later, and among these, diene rubbers are preferred. Details of diene rubbers will be described later.
The rubber having an unsaturated bond is preferably 25% by mass or more, more preferably 50% by mass or more, even more preferably 80% by mass or more, and still more preferably 100% by mass, based on the total amount of the matrix resin.

The type of rubber component is not particularly limited, but examples thereof include diene-based rubber, polyolefin-based rubber, and other rubbers. In addition, examples thereof include natural rubber, butyl rubber, chlorinated butyl rubber, chlorosulfonated polyethylene, acrylic rubber, epichlorohydrin rubber, multi-vulcanized rubber, non-vulcanized rubber, silicone rubber, fluororubber, and urethane rubber.
Among these, from the viewpoint of improving the cold resistance and fire resistance of the fire-resistant sheet, it is preferable that the rubber component contains at least one selected from diene-based rubbers and polyolefin-based rubbers, and it is more preferable that the rubber component contains a diene-based rubber.

Examples of diene rubbers include isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), acrylonitrile-butadiene rubber (NBR), and styrene-butadiene-styrene block copolymer (SBS).
Among these diene rubbers, from the viewpoint of improving the dispersibility of thermally expandable graphite, at least one selected from butadiene rubber (BR), styrene-butadiene rubber (SBR), and chloroprene rubber (CR) is preferred, and at least one selected from styrene-butadiene rubber (SBR) and chloroprene rubber (CR) is even more preferred.
From the viewpoint of increasing the dispersibility of the thermally expandable graphite and improving the cold resistance and fire resistance of the fire-resistant sheet, it is preferable to use two or more different diene rubbers in combination, and it is particularly preferable to use a combination of styrene-butadiene rubber (SBR) and chloroprene rubber (CR).
When styrene-butadiene rubber (SBR) and chloroprene rubber (CR) are used in combination, the content ratio thereof (SBR/CR) is preferably 90/10 to 10/90, and more preferably 80/20 to 20/80, in mass ratio.

The bound styrene content of the styrene-butadiene rubber (SBR) is not particularly limited, but from the viewpoint of improving the cold resistance of the fire-resistant sheet, it is, for example, 10 to 60 mass%, preferably 15 to 55 mass%, and more preferably 20 to 50 mass%. The bound styrene content can be measured by ^1H -NMR.
The Mooney viscosity [ML(1+4)100°C] of the styrene-butadiene rubber is not particularly limited, but from the viewpoint of improving the cold resistance of the fire-resistant sheet, it is, for example, 30 to 150, preferably 35 to 70, and more preferably 40 to 60.

The Mooney viscosity [ML(1+4)100°C] of the chloroprene rubber (CR) is not particularly limited, but from the viewpoint of improving the cold resistance of the fire-resistant sheet, it is, for example, 25 to 150, preferably 30 to 100, and more preferably 35 to 75.
In this specification, the Mooney viscosity is a value measured in accordance with JIS K6300.

Examples of polyolefin-based rubbers include ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), and olefin-based thermoplastic elastomers (TPOs). The above-mentioned olefin-based thermoplastic elastomers (TPOs) generally have polyolefins such as polyethylene and polypropylene as hard segments, and rubber components such as EPM and EPDM as soft segments. The olefin-based thermoplastic elastomers (TPOs) can be any of blend type, dynamic crosslinking type, and polymerization type.
Among the polyolefin rubbers, ethylene-propylene-diene rubber (EPDM) and olefin thermoplastic elastomer (TPO) are preferred from the viewpoint of improving the cold resistance of the fire-resistant sheet.

From the viewpoint of increasing the strength of the thermal expansion residue of the fire-resistant sheet and improving the fire resistance, the matrix resin of the present invention preferably contains a resin component containing at least one of a halogen atom, or a structural unit derived from styrene or vinyl acetate. The resin component containing at least one of a halogen atom, or a structural unit derived from styrene or vinyl acetate may be the rubber component described above, or a non-rubber component described below.

The rubber component is preferably a resin component containing a halogen atom or a structural unit derived from styrene, and the non-rubber component, which is blended as necessary, preferably contains the halogen atom or a structural unit derived from styrene or vinyl acetate.
Examples of resin components containing at least one of a halogen atom or a structural unit derived from styrene or vinyl acetate include the above-mentioned chloroprene rubber (CR), styrene-butadiene rubber (SBR), chlorinated butyl rubber, chlorosulfonated polyethylene, fluororubber, etc., as well as the below-mentioned polyvinyl chloride resin (PVC), ethylene-vinyl acetate copolymer resin, polystyrene resin, etc. Among these, chloroprene rubber (CR), styrene-butadiene rubber (SBR), polyvinyl chloride resin (PVC), ethylene-vinyl acetate copolymer resin, etc. are preferred.

The matrix resin may be composed of only one type of resin used as a rubber component, or may be composed of multiple resins. When composed of multiple resins, examples of the case where two or more types of rubber components are used, the case where one type of rubber component is used in combination with one or more types of non-rubber components, etc.
From the viewpoint of increasing the dispersibility of the thermally expandable graphite in the matrix resin and improving the cold resistance and fire resistance, the matrix resin is preferably composed of one type of resin, or if composed of multiple resins, the SP value difference between the multiple resins is preferably 2.0 or less. The SP value difference is preferably 1.5 or less, more preferably 1 or less. Here, the SP value difference between the multiple resins means the difference in SP value between the resin with the largest SP value and the resin with the smallest SP value among the multiple resins. The SP value is a solubility parameter, and is a value measured by the Fedors method.

The matrix resin of the present invention may contain, in addition to the above-mentioned rubber component, a non-rubber component that is a resin other than the rubber component.
The non-rubber component, which is a resin other than the rubber component, may be a thermoplastic resin or a thermosetting resin, but is preferably a thermoplastic resin.
Examples of the thermoplastic resin include polyolefin resins such as polypropylene resin, polyethylene resin, poly(1-)butene resin, and polypentene resin, polyester resins such as polyethylene terephthalate, polystyrene resin, acrylonitrile-butadiene-styrene (ABS) resin, ethylene-vinyl acetate copolymer resin (EVA), polycarbonate resin, polyphenylene ether resin, (meth)acrylic resin, polyamide resin, polyvinyl chloride resin (PVC), novolac resin, polyurethane resin, and polyisobutylene.
Among the thermoplastic resins, from the viewpoint of improving the fire resistance of the fire-resistant sheet, polyvinyl chloride resin and ethylene-vinyl acetate copolymer resin are preferred, and polyvinyl chloride resin is more preferred.

Examples of polyvinyl chloride resins (PVC) include homopolymers of vinyl chloride monomers, copolymers of vinyl chloride monomers and monomers having unsaturated bonds copolymerizable with vinyl chloride monomers, and graft copolymers in which vinyl chloride monomers are graft-copolymerized onto polymers or copolymers other than vinyl chloride monomers. These may be used alone or in combination of two or more.
In the present invention, chlorinated polyvinyl chloride resins, which are chlorinated polyvinyl chloride resins, are also included in the polyvinyl chloride resins.
The degree of polymerization of the polyvinyl chloride resin is preferably 500 to 2,000, and more preferably 800 to 1500. Within such a range, the fluidity of the resin component is increased, and the expansion ratio can be easily adjusted to a desired range.

The ethylene-vinyl acetate copolymer resin (EVA) may be a non-crosslinked ethylene-vinyl acetate copolymer resin or a high-temperature crosslinked ethylene-vinyl acetate copolymer resin. In addition, the ethylene-vinyl acetate copolymer resin may be a modified ethylene-vinyl acetate resin such as a saponification product of an ethylene-vinyl acetate copolymer or a hydrolyzate of ethylene-vinyl acetate.
The ethylene-vinyl acetate copolymer resin has a vinyl acetate content, as measured in accordance with JIS K 6730 "Testing methods for ethylene-vinyl acetate resins", of preferably 5 to 90 mass%, more preferably 8 to 50 mass%, and even more preferably 12 to 35 mass%.
The melt flow rate (MFR) of the ethylene-vinyl acetate copolymer resin at 190° C. is preferably 0.5 to 15 g/10 min, and more preferably 1 to 8 g/10 min. The melt flow rate of the ethylene-vinyl acetate copolymer at 190° C. is a value measured under a load of 2.16 kg in accordance with JIS K7210:1999.

The above-mentioned thermosetting resin is not particularly limited, but examples thereof include epoxy resin, polyurethane resin, phenol resin, melamine resin, urea resin, unsaturated polyester resin, alkyd resin, thermosetting polyimide, etc., and among these, epoxy resin is preferred from the viewpoint of improving fire resistance.

The epoxy resin may be an epoxy resin having an aromatic ring or an epoxy resin not having an aromatic ring, but from the viewpoint of enhancing non-flammability, an epoxy resin having an aromatic ring is preferable. The epoxy resin is obtained, for example, by reacting an epoxy resin compound having an epoxy group with a curing agent.
Examples of the epoxy resin compound used to obtain the above-mentioned epoxy resin having an aromatic ring include bisphenol A type epoxy resin compounds, bisphenol F type epoxy resin compounds, biphenyl type epoxy resin compounds, naphthalene type epoxy resin compounds, phenol novolac type epoxy resin compounds, bisphenol A novolac type epoxy resin compounds, tetraphenolethane type epoxy resin compounds, tetraglycidyldiaminodiphenylmethane type epoxy resin compounds, aminophenol type epoxy resin compounds, aniline type epoxy resin compounds, xylylenediamine type epoxy resin compounds, etc. Among these, bisphenol A type epoxy resin compounds and bisphenol F type epoxy resin compounds are preferred.

The curing agent used may be of polyaddition type or catalyst type. Examples of polyaddition type curing agents include polyamines, acid anhydrides, polyphenols, polymercaptans, etc. Examples of catalyst type curing agents include tertiary amines, imidazoles, Lewis acid complexes, etc. The method for curing the epoxy resin compound is not particularly limited, and may be performed by a known method.
The content of the curing agent is preferably within a range of 50 to 150 parts by mass relative to 100 parts by mass of the epoxy resin compound. When the content is 50 parts by mass or more, the epoxy resin compound is easily cured, and when the content is 150 parts by mass or less, an effect according to the amount of the curing agent is obtained.

Based on the total amount of the fire-resistant resin composition, the content of the matrix resin is preferably 20% by mass or more, more preferably 30% by mass or more, and preferably 65% by mass or less, more preferably 60% by mass or less. If the content of the matrix resin is equal to or greater than these lower limits, the cold resistance of the fire-resistant sheet is improved. If the content of the matrix resin is equal to or less than these upper limits, the content of the thermally expandable graphite and inorganic filler described below can be adjusted to be higher, improving the fire resistance.

<Plasticizer>
The fire-resistant resin composition of the present invention may contain a plasticizer. When the fire-resistant resin composition contains a plasticizer, the matrix resin becomes more fluid, and the fire-resistant sheet becomes more expandable. When a polyvinyl chloride resin is used as the matrix resin, it is preferable to use a plasticizer in combination. The moldability is improved by using a plasticizer in combination.

The plasticizer is not particularly limited, but examples thereof include phthalate ester plasticizers such as di-2-ethylhexyl phthalate (DOP), dibutyl phthalate (DBP), diheptyl phthalate (DHP), and diisodecyl phthalate (DIDP); fatty acid ester plasticizers such as di-2-ethylhexyl adipate (DOA), diisobutyl adipate (DIBA), and dibutyl adipate (DBA); epoxidized ester plasticizers such as epoxidized soybean oil; adipate ester plasticizers such as adipic acid esters and adipic acid polyesters; trimellitic acid ester plasticizers such as tri-2-ethylhexyl trimellitate (TOTM) and triisononyl trimellitate (TINTM); and process oils such as mineral oil. The plasticizers may be used alone or in combination of two or more.

When the fire-resistant resin composition of the present invention contains a plasticizer, the content is preferably 10 to 90 parts by mass, and more preferably 20 to 80 parts by mass, per 100 parts by mass of the matrix resin. When the plasticizer content is within the above range, extrusion moldability tends to improve, and the molded body can be prevented from becoming too soft.

<Thermal expandable graphite, inorganic filler>
The fire-resistant resin composition of the present invention contains thermally expandable graphite and an inorganic filler. The total content of the thermally expandable graphite and the inorganic filler in the fire-resistant resin composition is 35% by mass or more. If the total content of the thermally expandable graphite and the inorganic filler is less than 35% by mass, the expansion ratio of the fire-resistant sheet is reduced, the strength of the thermal expansion residue is reduced, and the fire resistance is reduced. From the viewpoint of improving fire resistance, the total content of the thermally expandable graphite and the inorganic filler is preferably 40% by mass or more, and from the viewpoint of increasing the amount of the matrix resin to improve cold resistance, it is preferably 80% by mass or less, more preferably 75% by mass or less.

Thermally expandable graphite expands when heated, and is produced by treating powders of natural scaly graphite, pyrolytic graphite, kish graphite, etc. with an inorganic acid and a strong oxidizing agent to generate a graphite intercalation compound, which is a type of crystalline compound that maintains the layered structure of carbon. Examples of inorganic acids include concentrated sulfuric acid, nitric acid, and selenic acid. Examples of strong oxidizing agents include concentrated nitric acid, perchloric acid, perchlorates, permanganates, dichromates, and hydrogen peroxide.
The thermally expandable graphite obtained by the acid treatment as described above may be further neutralized with a neutralizing agent such as ammonia, an aliphatic lower amine, an alkali metal compound, an alkaline earth metal compound, etc. Examples of the aliphatic lower amine include monomethylamine, dimethylamine, trimethylamine, ethylamine, propylamine, butylamine, etc. Examples of the alkali metal compound and the alkaline earth metal compound include hydroxides, oxides, carbonates, sulfates, organic acid salts, etc. of potassium, sodium, calcium, barium, magnesium, etc.

The content of thermally expandable graphite in the fire-resistant resin composition is preferably 15% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, and preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 45% by mass or less. If the content of thermally expandable graphite is equal to or greater than these lower limits, it becomes easier to obtain an expansion suitable for preventing the passage of fire, and if it is equal to or less than these upper limits, the strength of the thermal expansion residue of the fire-resistant sheet tends to be high, and the cold resistance of the fire-resistant sheet is improved, resulting in good processability.

The fire-resistant resin composition of the present invention contains an inorganic filler. When heated to form an expansion insulation layer, the inorganic filler increases the heat capacity and suppresses heat transfer, while acting as an aggregate to improve the strength of the thermal expansion residue.

From the viewpoint of improving the cold resistance of the fireproof sheet, it is preferable that the inorganic filler contains an inorganic filler A having a specific gravity of 2.5 or more. By including the inorganic filler A, the amount of matrix resin per unit volume can be increased, thereby improving the brittleness of the fireproof sheet and making it easier to improve the cold resistance. From this viewpoint, the specific gravity of the inorganic filler A is preferably 3 or more, more preferably 4 or more. For example, metal oxides and metal carbonates described later can be used as the inorganic filler A having a specific gravity of 2.5 or more. The inorganic filler A may be used alone or in combination.
The content of the inorganic filler A based on the total amount of the inorganic fillers is preferably 50% by mass or more, more preferably 80% by mass or more, and even more preferably 100% by mass.

As the inorganic filler, it is preferable to use the above-mentioned inorganic filler A having a specific gravity of 2.5 or more, but it is also possible to use an inorganic filler having a specific gravity of less than 2.5.
The inorganic filler that can be used in the present invention is not particularly limited, and examples thereof include metal oxides such as alumina, zinc oxide, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, and ferrite; metal carbonates such as calcium carbonate, zinc carbonate, strontium carbonate, and barium carbonate; metal hydroxides such as calcium hydroxide, magnesium hydroxide, aluminum hydroxide, and hydrotalcite; calcium sulfate, gypsum fiber, calcium salts such as calcium silicate; silica, diatomaceous earth, dawsonite, barium sulfate, talc, clay, mica, montmorillonite, bentonite, activated clay, sepiolite, imogolite, sericite, glass fiber, glass beads, Examples of suitable inorganic fillers include silica-based balloons, aluminum nitride, boron nitride, silicon nitride, carbon black, graphite, carbon fibers, carbon balloons, various metal powders, potassium titanate, magnesium sulfate, lead zirconate titanate, aluminum borate, molybdenum sulfide, silicon carbide, stainless steel fibers, zinc borate, various magnetic powders, slag fibers, fly ash, metal phosphates such as sodium phosphate, potassium phosphate, magnesium phosphate, and aluminum phosphate, metal phosphite such as sodium phosphite, potassium phosphite, magnesium phosphite, and aluminum phosphite, ammonium polyphosphate, metal orthophosphate, metal metaphosphate, and metal tripolyphosphate. The inorganic fillers may be used alone or in combination of two or more.

Among these, from the viewpoint of improving fire resistance, the inorganic filler is preferably a metal oxide, a metal hydroxide, a metal carbonate, etc., and more preferably at least one selected from iron oxide, aluminum hydroxide, and calcium carbonate. More specifically, the inorganic filler is more preferably at least iron oxide, and it is particularly preferable to use iron oxide and calcium carbonate in combination. By using iron oxide, even if the expansion ratio of the fire-resistant sheet is relatively large, the strength of the thermal expansion residue is easily maintained, and therefore the fire resistance is easily improved.
When iron oxide is used, the amount used is preferably 15 mass % or more, more preferably 25 mass % or more, and even more preferably 40 mass % or more, based on the total amount of the inorganic filler.
When iron oxide and calcium carbonate are used in combination, the mass ratio thereof (iron oxide/calcium carbonate) is preferably 10/90 to 90/10, and more preferably 20/80 to 80/20.

The content of the inorganic filler in the fire-resistant resin composition is preferably 3% by mass or more, more preferably 8% by mass or more, even more preferably 13% by mass or more, and is preferably 50% by mass or less, more preferably 30% by mass or less.

<Other ingredients>
The fire-resistant resin composition may contain various additives, such as various organic flame retardants such as a bromine-containing flame retardant, a nitrogen-containing flame retardant, and a phosphate ester compound, a colorant, and an antioxidant, in addition to the above-mentioned matrix resin, thermally expandable graphite, and inorganic filler.

Examples of bromine-containing flame retardants include hexabromobenzene, pentabromotoluene, hexabromobiphenyl, decabromobiphenyl, hexabromocyclodecane, decabromodiphenyl ether, octabromodiphenyl ether, hexabromodiphenyl ether, bis(pentabromophenoxy)ethane, ethylene-bis(tetrabromophthalimide), tetrabromobisphenol A, etc.

Examples of nitrogen-containing flame retardants include melamine derivatives such as melamine, butyl melamine, trimethylol melamine, hexamethylol melamine, hexamethoxymethyl melamine, and melamine phosphate; cyanuric acid derivatives such as cyanuric acid, methyl cyanurate, diethyl cyanurate, trimethyl cyanurate, and triethyl cyanurate; isocyanuric acid derivatives such as isocyanuric acid, methyl isocyanurate, N,N'-diethyl isocyanurate, trismethyl isocyanurate, trisethyl isocyanurate, bis(2-carboxyethyl)isocyanurate, 1,3,5-tris(2-carboxyethyl)isocyanurate, and tris(2,3-epoxypropyl)isocyanurate; melamine cyanurate, melamine isocyanurate, and ammonium carbonate.

Examples of phosphate ester compounds include trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, octyl diphenyl phosphate, tributoxyethyl phosphate, trichloroethyl phosphate, tris(2-chloropropyl)phosphate, tris(2,3-dichloropropyl)phosphate, tris(2,3-dibromopropyl)phosphate, tris(bromochloropropyl)phosphate, bis(2,3-dibromopropyl)-2,3-dichloropropyl phosphate, bis(chloropropyl)monoctyl phosphate, tris(2-ethylhexyl)phosphate, triphenyl phosphate, tricresyl phosphate (TCP), trixylenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, etc.

<Phosphorus component>
The fire-resistant resin composition of the present invention preferably does not contain a phosphorus component. By not containing a phosphorus component, the water resistance of the fire-resistant sheet formed from the fire-resistant composition is improved. Therefore, even after long-term exposure to water, excellent expansion ratio, residual hardness, and shape retention after expansion can be ensured. Here, the phosphorus component is a compound containing a phosphorus atom, and it is preferable not to use a compound containing a phosphorus atom as the above-mentioned matrix resin, thermally expandable graphite, inorganic filler, and additives such as organic flame retardants, colorants, and antioxidants that are mixed as necessary.

[Fireproof sheet]
The fire-resistant resin composition of the present invention can be used to form a fire-resistant sheet made of the fire-resistant resin composition.
The expansion ratio of the fire-resistant sheet in the thickness direction is not particularly limited, but from the viewpoint of fire resistance and water resistance, it is preferably 5 to 70 times, more preferably 10 to 60 times, and even more preferably 15 to 55 times. It is preferable that the fire-resistant sheet of the present invention shows an expansion ratio in the above range even after being immersed in water for a long time. The expansion ratio is measured by the method described in the examples.

The thickness of the fireproof sheet is not particularly limited, but from the standpoint of fire resistance and ease of handling, a thickness of 0.2 to 10 mm is preferable, and a thickness of 0.5 to 3.0 mm is more preferable.

As described above, the fire-resistant sheet of the present invention has excellent cold resistance and is unlikely to break or develop surface cracks during use, making it easy to handle even when the sheet is long, and it can be used as a long product, for example, 1 m or longer.

The fire-resistant sheet of the present invention can be produced, for example, as follows.
First, predetermined amounts of a matrix resin, thermally expandable graphite, and inorganic filler resin, as well as additives such as an organic flame retardant, a colorant, and an antioxidant, which are blended as necessary, are kneaded in a kneading machine such as a kneading roll to obtain a fire-resistant resin composition.
Next, the obtained fire-resistant resin composition is molded into a sheet by a known molding method such as press molding, calendar molding, extrusion molding, etc., to obtain a fire-resistant sheet.

The fire-resistant sheet can be used in various buildings such as detached houses, apartment buildings, high-rise buildings, high-rise buildings, commercial facilities, public facilities, etc., various vehicles such as automobiles and trains, and various vehicles such as ships and aircraft. When a fire breaks out in a building or vehicle, the fire-resistant sheet expands when heated, blocking the flow of air and demonstrating its fire-extinguishing properties.
The fireproof sheet is attached to components constituting the above-mentioned buildings, vehicles, ships, aircraft, etc., and is used. For example, in buildings, the fireproof sheet is attached to fittings such as windows, shoji screens, doors, doors, and sliding doors, pillars, walls made of steel concrete, floors, roofs, etc., to reduce or prevent the intrusion of fire and smoke. Among these, the use in fittings is preferable. That is, one embodiment of the present invention also provides fittings equipped with the fireproof sheet.

The fireproof sheet may be used alone, or may be used with other members attached as appropriate. For example, the fireproof sheet may be laminated with members other than the fireproof sheet, and a substrate may be provided on at least one surface of the fireproof sheet. The substrate may be a combustible material layer, or a quasi-noncombustible material layer or a noncombustible material layer. The thickness of the substrate is not particularly limited, but is, for example, 5 μm to 1 mm. Examples of materials used for the combustible material layer include one or more of cloth materials, paper materials, wood materials, resin films, etc. When the substrate is a quasi-noncombustible material layer or a noncombustible material layer, examples of the materials used include metals, inorganic materials, etc., and more specifically, woven or nonwoven fabrics made of glass fibers, ceramic fibers, carbon fibers, and graphite fibers. Composite materials of these fibers and metals may also be used, and aluminum glass cloth is preferable. An adhesive layer may also be laminated on the sheet-shaped fireproof material. The adhesive layer may be provided on the substrate, or may be formed directly on the surface of the fireproof sheet.

The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these.

[Evaluation method]
(1) Dissolution Rate Five test pieces (length 50 mm, width 50 mm, thickness 1.5 mm) made from the obtained fireproof sheets of each Example and Comparative Example were immersed in 200 g of pure water and left to soak in a sealed container at 60° C. for one week, after which the samples were removed, the pure water in which they had been immersed was evaporated and dried at 60° C. for 96 hours, and the mass of the precipitate that had formed was measured. The measured value was used to calculate the dissolution rate according to the following formula, which was used as an index of water resistance.
Dissolution rate (%) = [(mass of precipitate) / (mass of fireproof sheet before immersion in pure water)] x 100
(2) Expansion ratio A test piece (length 100 mm, width 100 mm, thickness 1.5 mm) made from the obtained fireproof sheet was immersed in 500 mL of pure water at 60 ° C. in a closed container for one week, and then the sample was taken out. The sample was evaporated and dried at 60 ° C. for 96 hours to prepare a test piece, which was placed on the bottom of a stainless steel holder (101 mm square, height 80 mm), fed into an electric furnace, and heated at 600 ° C. for 30 minutes. Thereafter, the height (highest part), width, length, and thickness of the test piece were measured, and the expansion ratio was calculated by ((thickness of the test piece after heating) / (thickness of the test piece before heating)).

(3) Residual Hardness The heated test piece after measuring the expansion ratio was fed into a compression tester ("Finger Feeling Tester" manufactured by Kato Tech Co., Ltd.) and compressed at a speed of 0.1 cm/sec with a three-point indenter having a diameter of 1 mm. The maximum stress up to a compression depth of 10 mm from the top surface of the residue was measured, and the compressive strength (kgf/ ^cm2 ) of the test piece after combustion was measured.

(4) Cold resistance (brittleness)
The long fireproof sheets obtained in each of the Examples and Comparative Examples were wound up into rolls, which were then re-deployed at 0° C. and −20° C. for evaluation. During the unfolding process, the appearance of the sheet was observed to check whether the surface was cracked or broken. Evaluation was based on the following criteria.
⊚: The sheet was able to be deployed without cracking or breaking.
(-20℃)
◯: The sheet was able to be deployed without cracking or breaking.
(0°C)
△: Cracks occurred in the sheet when unfolded.
(0°C)
x: The sheet broke when unfolded.
(0°C)

(Examples 1 to 27, Comparative Examples 1 to 4)
A matrix resin, thermally expandable graphite, inorganic filler, plasticizer, and additives were put into a roll and kneaded at 150° C. for 5 minutes according to the formulations shown in Tables 1 to 3 below to obtain a fire-resistant resin composition. The obtained fire-resistant resin composition was press-molded at 150° C. for 3 minutes to obtain a fire-resistant sheet having a thickness of 1.5 mm. The components used in each of the examples and comparative examples are as follows.

(1) Matrix resin <Chloroprene rubber: CR>
・CR Tosoh Corporation "Y-20E"
Mooney viscosity [ML(1+4)100°C]: 43-53
・CR1 Tosoh Corporation "E-20H"
Mooney viscosity [ML(1+4)100°C]: 54-74
・CR2 Tosoh Corporation "R-10"
Mooney viscosity [ML(1+4)100°C]: 35-55

<Styrene-butadiene rubber: SBR>
・SBR JSR Corporation "JSR1500"
Bound styrene content: 23.5% by mass, Mooney viscosity [ML(1+4)100°C]: 52
・SBR2 JSR Corporation "JSR0202"
Bound styrene content: 46% by mass, Mooney viscosity [ML(1+4)100°C]: 45
・SBR3 JSR Corporation "JSR0122"
Bound styrene content: 37% by mass, Mooney viscosity [ML(1+4)100°C]: 52

<Styrene-butadiene-styrene copolymer: SBS>
・SBS JSR Corporation "TR1086"
Bound styrene content: 45% by mass

<Ethylene-propylene-diene rubber: EPDM>
・EPDM "ENB-EPT X-3012P" manufactured by Mitsui Chemicals, Inc.

<Olefin-based thermoplastic elastomer: TPO>
・TPO: "Milastomer 5020BS" manufactured by Mitsui Chemicals, Inc.

<Ethylene-vinyl acetate copolymer resin: EVA>
・EVA Mitsui DuPont Polychemicals Co., Ltd. "EV460"
Vinyl acetate content: 19% by mass, MFR (190°C): 2.5g/10min
<Polyvinyl chloride resin: PVC>
PVC: Shin-Etsu Chemical Co., Ltd. "TK-1000", average degree of polymerization 1030

(2) Plasticizer: DOP Di-2-ethylhexyl phthalate, "DOP" manufactured by JPlus Corporation

(3) Thermally expandable graphite Thermally expandable graphite "CA-60N" manufactured by Air Water Corporation

(4) Inorganic filler/iron oxide: Titanium Kogyo Co., Ltd. "BL-100", specific gravity 5.1
Calcium carbonate: Bihoku Powder Industry Co., Ltd. "Whiten BF-300", specific gravity 2.93
Aluminum hydroxide: Hayashi Kasei Co., Ltd. "C-305", specific gravity 2.42

(5) Additives: EDAP (ethylenediamine phosphate) "Amgard EDAP" manufactured by Albright & Wilson

As shown in the examples, it was found that a fire-resistant sheet formed from a fire-resistant resin composition having a total content of thermally expandable graphite and inorganic filler of 35 mass % or more and a rubber component content of 15 mass % or more based on the total amount of matrix resin had good fire resistance as seen from a high residual hardness value, and also had excellent cold resistance.
On the other hand, fire-resistant sheets formed from fire-resistant resin compositions in which the total content of thermally expandable graphite and inorganic filler was less than 35 mass % or the rubber component content was less than 15 mass % based on the total amount of matrix resin showed deterioration in at least one of the physical properties of fire resistance and cold resistance.

Claims (8)

Contains a matrix resin, thermally expandable graphite, and an inorganic filler;
The total content of the thermally expandable graphite and the inorganic filler is 35% by mass or more,
The fire-resistant resin composition, wherein the matrix resin contains a rubber component, and the content of the rubber component is 15 mass% or more based on the total amount of the matrix resin. The fire-resistant resin composition according to claim 1, wherein the rubber component contains a rubber having an unsaturated bond. The fire-resistant resin composition according to claim 1 or 2, wherein the matrix resin contains a resin component containing at least one of a halogen atom, or a structural unit derived from styrene or vinyl acetate. The fire-resistant resin composition according to any one of claims 1 to 3, wherein the inorganic filler contains inorganic filler A having a specific gravity of 2.5 or more. The fire-resistant resin composition according to any one of claims 1 to 4, which does not contain a phosphorus component. A fire-resistant sheet made of the fire-resistant resin composition according to any one of claims 1 to 5. The fireproof sheet according to claim 6, which is a long product having a length of 1 m or more. A fitting equipped with the fireproof sheet according to claim 6 or 7.