JP7442271B2 - Expandable urethane resin composition and polyurethane foam - Google Patents

Description

The present invention relates to a foamable urethane resin composition and a polyurethane foam made from the composition.

Utilizing its excellent heat insulating properties, polyurethane foam is put to practical use in insulating and preventing condensation on ceilings, roofs, walls, etc. of buildings such as condominiums and other housing complexes, detached houses, and commercial buildings. Although polyurethane foam is lightweight, it is organic and therefore flammable. In order to improve this problem, polyurethane foams are used in which flame retardants are added to the polyurethane foams to improve flame retardancy. For example, Patent Document 1 describes a flame-retardant polyurethane foam obtained using ammonium polyphosphate, a urea derivative, a polyol, and an isocyanate. The flame-retardant polyurethane foam is characterized in that ammonium polyphosphate is used in an amount of 5 to 150 parts by weight and urea derivative is used in an amount of 0.001 to 15 parts by weight based on 100 parts by weight of polyol.

Japanese Patent Application Publication No. 2015-151524

In recent years, there have been relatively many reports of fires caused by polyurethane foams used as insulation materials in buildings. In order to improve these problems, it is expected to develop a polyurethane foam that not only has excellent flame retardancy but also has the property of being difficult to spread when a fire breaks out.
By incorporating a large amount of highly flame-retardant compounds such as red phosphorus, it is possible to give polyurethane foam properties that make it difficult for flames to spread, but the foam takes on the dark red coloration characteristic of red phosphorus, which may affect the color tone of the product. Problems may arise. Depending on the use of polyurethane foam, it may be colored by adding a dye or the like, but the dark red characteristic of red phosphorus prevents the dye from developing color.
Therefore, an object of the present invention is to provide a foamable urethane resin composition for producing a polyurethane foam that does not contain red phosphorus and has properties that prevent it from spreading, and a polyurethane foam made of the composition.

As a result of extensive studies, the present inventors have discovered a foamable urethane resin composition containing a polyol compound, a polyisocyanate compound, a foam stabilizer, a blowing agent, a catalyst, and an additive, the foamable urethane resin composition comprising: The inventors have discovered that the above-mentioned problems can be solved with a composition that does not substantially contain red phosphorus and in which the sinking distance of a steel ball is below a certain value, and has completed the present invention. That is, the present invention provides the following [1] to [10].
[1] A foamable urethane resin composition containing a polyol compound, a polyisocyanate compound, a foam stabilizer, a blowing agent, a catalyst, and an additive, the foamable urethane resin composition substantially containing red phosphorus. A foamable urethane resin composition in which the sinking distance of a steel ball is 20 mm or less in the following steel ball sinking evaluation of a polyurethane foam made of the foamable urethane resin composition.
(Steel ball sinking evaluation)
(1) A polyurethane foam is cut into a cube with each side of 50 mm and used as a test piece.
(2) Place a wire mesh at a point 30 mm from the burner mouth of a Bunsen burner (outer flame length 70 mm), place a steel ball with a diameter of 4.7 mm and a weight of 0.44 g on the wire mesh, and the entire steel ball turns red. Heat the steel ball for at least 5 minutes or more until the steel ball temperature changes to 750°C or higher.
(3) In an atmosphere of 23° C., immediately place the steel ball heated in (2) above on the center of the upper part of the test specimen in (1) above, and leave it until the steel ball sinks completely. Next, a cross section of the sufficiently cooled test specimen is cut to measure the sinking distance of the steel ball.
[2] The total calorific value after 5 minutes when the polyurethane foam made of the foamable urethane resin composition is heated at a radiant heat intensity of 50 kW/m ² in accordance with the ISO-5660 test method. The foamable urethane resin composition according to the above [1], wherein the foaming capacity is 8 MJ/m ² or less.
[3] The foamable urethane resin composition according to [1] or [2] above, wherein the polyol compound is an aromatic polyol compound.
[4] The foamable urethane resin composition according to any one of [1] to [3] above, wherein the catalyst includes a trimerization catalyst.
[5] The foamable urethane resin composition according to any one of [1] to [4] above, which has an isocyanate index of 200 to 700.
[6] The above-mentioned [1] to [5] contains a flame retardant as the additive, and the content of the flame retardant is 1 part by mass or more based on 100 parts by mass of the urethane resin consisting of a polyol compound and a polyisocyanate compound. ] The foamable urethane resin composition according to any one of the above.
[7] The foamable urethane resin composition according to any one of [1] to [6] above, which is a foamable urethane resin composition for spraying.
[8] The foamable urethane resin composition according to any one of [1] to [7] above, which contains a solid flame retardant and a liquid flame retardant as the additive.
[9] The additive includes a flame retardant, and the flame retardant is a phosphate-based flame retardant, a boron-containing flame retardant, a bromine-containing flame retardant, a phosphate-containing flame retardant, an antimony-containing flame retardant, or a phosphinic acid-based flame retardant. The foamable urethane resin composition according to any one of [1] to [8] above, which is at least one selected from a flame agent and a metal hydroxide flame retardant.
[10] Polyurethane foam, which is formed from the foamable urethane resin composition according to any one of [1] to [9] above, and has a steel ball sinking distance of 20 mm or less in the steel ball sinking evaluation above. body.

According to the present invention, a foamable urethane foam that does not substantially contain red phosphorus, thereby making it possible to produce a polyurethane foam that does not have the coloring characteristic of red phosphorus and has properties that prevent it from spreading in the event of a fire, etc. A resin composition and a polyurethane foam made of the same can be provided.

[Foamable urethane resin composition]
The foamable urethane resin composition of the present invention is a composition containing a polyol compound, a polyisocyanate compound, a foam stabilizer, a blowing agent, a catalyst, and an additive, and the foamable urethane resin composition contains red phosphorus. The sinking distance of a steel ball in the following steel ball sinking evaluation of a polyurethane foam made of the above-mentioned expandable urethane resin composition is 20 mm or less.
(Steel ball sinking evaluation)
(1) A polyurethane foam is cut into a cube with each side of 50 mm and used as a test piece.
(2) Place a wire mesh at a point 30 mm from the burner mouth of a Bunsen burner (outer flame length 70 mm), place a steel ball with a diameter of 4.7 mm and a weight of 0.44 g on the wire mesh, and the entire steel ball turns red. Heat for at least 5 minutes or more until the steel ball temperature changes to 750°C or higher. Bunsen burners use LPG combustion gas.
(3) In an atmosphere of 23° C., immediately place the steel ball heated in (2) above on the center of the upper part of the test specimen in (1) above, and leave it until the steel ball sinks completely. Next, a cross section of the sufficiently cooled test specimen is cut to measure the sinking distance of the steel ball.

In the above steel ball sinkage evaluation, regarding the diameter and weight of the steel ball, if the diameter is within the range of 4.7 ± 0.5 mm and the weight is within the range of 0.44 ± 0.5 g, the other conditions are as above. This results in equivalent steel ball sinkage evaluation, so it may be carried out within such diameter and weight ranges.
Further, the outer flame length means the length of the flame in the direction directly above the center of the burner mouth.

The polyurethane foam made of the foamable urethane resin composition of the present invention has a steel ball sinking distance of 20 mm or less in steel ball sinking evaluation. If the sinking distance of the steel ball exceeds 20 mm, the polyurethane foam is likely to catch fire when exposed to fire, making it difficult to effectively prevent the spread of fire. From the viewpoint of effectively preventing the spread of fire, the sinking distance of the steel ball is preferably 15 mm or less, more preferably 10 mm or less, and still more preferably 5 mm or less. Note that the sinking distance of the steel ball is 0 mm or more.
The steel ball sinking distance can be adjusted to a desired value by adjusting the type of polyol compound contained in the foamable urethane resin composition, the content of flame retardants other than red phosphorus, and the like.

The polyurethane foam used in the steel ball sinking evaluation was produced under the conditions described in Examples.

(red phosphorus)
The foamable urethane resin composition of the present invention does not substantially contain red phosphorus. By substantially not containing red phosphorus, it is possible to prevent the polyurethane foam from coloring peculiar to red phosphorus, making it easier to adjust the color of the product to the desired color tone. In the present invention, "not substantially containing" means not intentionally blending.

(Total calorific value)
When a polyurethane foam made of the foamable urethane resin composition of the present invention is heated at a radiant heat intensity of 50 kW/ ^m2 in accordance with the ISO-5660 test method, the total calorific value after 5 minutes is It is preferably 8 MJ/m ² or less. Since the total calorific value is 8 MJ/m ² or less, the polyurethane foam made of the foamable urethane resin composition of the present invention has a predetermined flame retardancy. By having a specified flame retardant property and the steel ball sinking distance being less than a certain value as mentioned above, the polyurethane foam is both flame retardant and has the property of not spreading when a fire occurs. The spread of fire can be more effectively prevented.
From the viewpoint of further improving the flame retardance of the polyurethane foam, the total calorific value is preferably 7 MJ/m ² or less, more preferably 5 MJ/m ² or less.
The above gross calorific value is obtained by a cone calorimeter test, and can be measured in detail by the method described in the Examples.
In addition, during the above-mentioned cone calorimeter test, it is preferable that the polyurethane foam subjected to the test has shape stability to the extent that it does not come into contact with the spark igniter of the cone calorimeter.

(Polyol compound)
The polyol compound contained in the foamable urethane resin composition of the present invention is not particularly limited, but polyether polyols and polyester polyols are preferred. Among these, aromatic polyol compounds such as aromatic polyether polyols and aromatic polyester polyols are preferred, as will be described later, from the viewpoint of improving the flame retardance of the resulting polyurethane foam.

<Polyether polyol>
Polyether polyol is a polyoxyalkylene polyol obtained by ring-opening addition polymerization of alkylene oxide to an initiator having two or more active hydrogen atoms. Specific examples of the initiator include aliphatic polyhydric alcohols (e.g., ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 1,6-hexane). diols, glycols such as neopentyl glycol, cyclohexylene glycol, and cyclohexanedimethanol, triols such as trimethylolpropane and glycerin, and tetrafunctional alcohols such as pentaerythritol), aliphatic amines (e.g. ethylenediamine, propylene diamine, butylene) diamines, alkylene diamines such as hexamethylene diamine and neopentyl diamine, alkanolamines such as monoethanolamine and diethanolamine), aromatic amines (e.g. aniline, tolylene diamine, xylylene diamine, diphenylmethane diamine, Mannich condensation products, etc.), etc. These may be used alone or in combination of two or more.
As the polyether polyol, aromatic polyether polyols having an aromatic ring in the molecule are preferable from the viewpoint of improving the flame retardancy of the polyurethane foam, and among them, amines such as tolylene diamine-based polyether polyols and Mannich-based polyether polyols are preferable. Mannich type polyether polyols are preferred, and Mannich type polyether polyols are more preferred.
Note that the above-mentioned tolylene diamine-based polyether polyol is a polyether polyol obtained using tolylene diamine as an initiator. The above-mentioned Mannich polyether polyol is a polyether polyol obtained using a Mannich condensate as an initiator, and is produced using a Mannich reaction with phenols, primary or secondary amines, and aldehydes. It is a polyether polyol.

The hydroxyl value of the polyether polyol is preferably 200 to 1000 mgKOH/g, more preferably 300 to 600 mgKOH/g. The hydroxyl value is a value measured in accordance with JIS K1557-1:2007.

<Polyester polyol>
Examples of polyester polyols include aromatic polyester polyols and aliphatic polyester polyols, but in consideration of the flame retardancy of the resulting polyurethane foam, it is preferable to use aromatic polyester polyols. The aromatic polyester polyol must be a condensation product of aromatic dicarboxylic acids such as o-phthalic acid (phthalic acid), m-phthalic acid (isophthalic acid), p-phthalic acid (terephthalic acid), naphthalene dicarboxylic acid, and glycol. is preferred. Among these, we aim to improve the flame retardancy of polyurethane foam, to reduce the steel ball sinking distance mentioned above to improve its ability to prevent flame spread, and to make it less likely that the foam will undergo shape deformation when heated. From this point of view, phthalic acid-based polyester polyols are preferred, which are condensates of at least one of o-phthalic acid, m-phthalic acid, and p-phthalic acid and glycol; More preferred is p-phthalic acid polyester polyol.
The glycol is not particularly limited, but it is preferable to use low molecular weight aliphatic glycols known as constituents of polyester polyols such as ethylene glycol, propylene glycol, and diethylene glycol.

Among the above-mentioned polyol compounds, aromatic polyol compounds are preferred from the viewpoint of increasing the flame retardancy of the polyurethane foam, and from the viewpoint of reducing the steel ball sinking distance described above and improving the performance of preventing the spread of flame. More preferably, the polyol compound contains at least one of a phthalic acid polyester polyol and an amine polyether polyol.

The hydroxyl value of the polyester polyol is preferably 100 to 400 mgKOH/g, more preferably 150 to 350 mgKOH/g.

The polyol compound preferably contains an aromatic polyol compound in an amount of 50% by mass or more, more preferably 80% by mass or more, and even more preferably 100% by mass.
Further, the aromatic polyol compound preferably contains at least 50% by mass, more preferably 80% by mass or more, and even more preferably 100% by mass of at least one of phthalic acid polyester polyol and amine polyether polyol. .

(Polyisocyanate compound)
As the polyisocyanate compound contained in the foamable urethane resin composition, various polyisocyanate compounds having two or more isocyanate groups, such as aromatic, alicyclic, and aliphatic, can be used. Preferably, liquid diphenylmethane diisocyanate (MDI) is used because of its ease of handling, speed of reaction, excellent physical properties of the resulting polyurethane foam, and low cost. Examples of liquid MDI include crude MDI (also referred to as polymeric MDI). Specific commercial products of liquid MDI include "44V-10", "44V-20" (manufactured by Sumika Covestro Urethane Co., Ltd.), and "Millionate MR-200" (Japan Polyurethane Industries). Alternatively, MDI containing uretonimine (for example, "Millionate MTL" as a commercially available product, manufactured by Nippon Polyurethane Industries) may be used. In addition to liquid MDI, other polyisocyanate compounds may be used in combination, and any polyisocyanate compound known in the technical field of polyurethane can be used without limitation.

The isocyanate index (NCO INDEX) in the foamable urethane resin composition is not particularly limited, but from the viewpoint of improving flame retardancy, it is preferably 200 to 700, more preferably 250 to 500, and even more preferably 250 to 400.
Here, the isocyanate index refers to the equivalent ratio of the isocyanate groups of the polyisocyanate compound to all active hydrogen groups contained in the foamable urethane resin composition (water as a blowing agent is calculated as a bifunctional active hydrogen compound). It means what is expressed as a percentage (equivalent ratio of isocyanate groups to 100 equivalents of active hydrogen groups).

(Additive)
The foamable urethane resin composition of the present invention preferably contains a flame retardant as an additive. Flame retardants include, but are not limited to, phosphate-based flame retardants, boron-containing flame retardants, bromine-containing flame retardants, phosphate-containing flame retardants, antimony-containing flame retardants, phosphinic acid-based flame retardants, and metal hydroxides. It is preferable that the flame retardant is at least one selected from flame retardants.
The content of the flame retardant is not particularly limited, but is preferably 1 part by mass or more, more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, and preferably It is 40 parts by mass or less, more preferably 30 parts by mass or less.

Moreover, it is also preferable that the foamable urethane resin composition of the present invention contains a liquid flame retardant and a solid flame retardant as additives. This improves the flame retardancy of the resulting polyurethane foam and makes it difficult for the polyurethane foam to deform when exposed to heat. In particular, it is preferable to use a phosphate ester flame retardant, which will be described later, as a liquid flame retardant, and a boric acid-containing flame retardant, which will be described later, as a solid flame retardant, and to use these in combination.
Here, the solid flame retardant refers to a flame retardant that is solid at 23°C, and the liquid flame retardant refers to a flame retardant that is liquid at 23°C.

Examples of solid flame retardants include boron-containing flame retardants, bromine-containing flame retardants, phosphate-containing flame retardants, antimony-containing flame retardants, phosphinic acid-based flame retardants, and metal hydroxide-based flame retardants, among others. , boron-containing flame retardants, and bromine-containing flame retardants are preferred, and boron-containing flame retardants are more preferred. By using a solid flame retardant, it becomes easier to suppress shape deformation when the polyurethane foam is exposed to heat.

<Boron-containing flame retardant>
Examples of boron-containing flame retardants include alkali metal borates such as lithium borate, sodium borate, potassium borate, and cesium borate, and boric acids such as magnesium borate, calcium borate, and barium borate. Examples include alkaline earth metal salts, zirconium borate, zinc borate, aluminum borate, ammonium borate, and the like. Among these, zinc borate is preferred.

<Brominated flame retardant>
The brominated flame retardant is not particularly limited as long as it is a compound containing bromine in its molecular structure, and examples thereof include aromatic brominated compounds.
Specific examples of the aromatic brominated compounds include hexabromobenzene, pentabromotoluene, hexabromobiphenyl, decabromobiphenyl, hexabromocyclodecane, decabromodiphenyl ether, octabromodiphenyl ether, hexabromodiphenyl ether, and bisbromodiphenyl ether. (pentabromophenoxy)ethane, ethylenebis(pentabromophenyl), ethylenebis(tetrabromophthalimide), tetrabromobisphenol A, and other monomeric organic bromine compounds, polycarbonate oligomers produced using brominated bisphenol A as raw materials; Brominated polycarbonates such as copolymers of polycarbonate oligomers and bisphenol A, diepoxy compounds produced by the reaction of brominated bisphenol A and epichlorohydrin, and monoepoxy compounds obtained by the reaction of brominated phenols with epichlorohydrin, etc. epoxy compounds, poly(brominated benzyl acrylate), brominated polyphenylene ether, brominated bisphenol A, condensates of cyanuric chloride and brominated phenol, brominated (polystyrene), poly(brominated styrene), crosslinked brominated polystyrene, etc. Examples include halogenated bromine compound polymers such as brominated polystyrene, crosslinked or non-crosslinked brominated poly(α-methylstyrene).
Among these, ethylenebis(pentabromophenyl), ethylenebis(tetrabromophthalimide), hexabromobenzene and the like are preferred.

<Phosphate-containing flame retardant>
Phosphate-containing flame retardants include, for example, phosphoric acid salts of phosphoric acid and at least one metal or compound selected from metals of Groups IA to IVB of the Periodic Table, ammonia, aliphatic amines, and aromatic amines. Mention may be made of acid salts.
The phosphoric acid is not particularly limited, but various phosphoric acids such as monophosphoric acid, pyrophosphoric acid, and polyphosphoric acid can be mentioned.
Examples of the metals of Groups IA to IVB of the periodic table include lithium, sodium, calcium, barium, iron (II), iron (III), aluminum, and the like. Examples of the aliphatic amine include methylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, piperazine, and the like. Further, examples of the aromatic amine include pyridine, triazine, melamine, and the like.
In addition, the above-mentioned phosphate-containing flame retardant may be subjected to known water resistance improvement treatments such as silane coupling agent treatment and coating with melamine resin.

Specific examples of phosphate-containing flame retardants include monophosphates, pyrophosphates, polyphosphates, and the like.
Monophosphates are not particularly limited, but include, for example, ammonium salts such as ammonium phosphate, ammonium dihydrogen phosphate, and ammonium hydrogen phosphate, monosodium phosphate, disodium phosphate, trisodium phosphate, and phosphorous acid. Sodium salts such as monosodium, disodium phosphite, sodium hypophosphite, monopotassium phosphate, dipotassium phosphate, tripotassium phosphate, monopotassium phosphite, dipotassium phosphite, hypophosphorous acid Potassium salts such as potassium, monolithium phosphate, dilithium phosphate, trilithium phosphate, monolithium phosphite, dilithium phosphite, lithium hypophosphite, etc., barium dihydrogen phosphate, phosphorus Barium salts such as barium oxyhydrogen, tribarium phosphate, barium hypophosphite, magnesium salts such as monohydrogen phosphate, magnesium hydrogen phosphate, trimagnesium phosphate, magnesium hypophosphite, calcium dihydrogen phosphate , calcium salts such as calcium hydrogen phosphate, tricalcium phosphate, and calcium hypophosphite, and zinc salts such as zinc phosphate, zinc phosphite, and zinc hypophosphite.

Further, the polyphosphate is not particularly limited, but examples thereof include ammonium polyphosphate, piperazine polyphosphate, melamine polyphosphate, ammonium amide polyphosphate, aluminum polyphosphate, and the like.
Among these, monophosphates are preferably used, and ammonium dihydrogen phosphate is more preferably used, since the self-extinguishing properties of the phosphate-containing flame retardant are improved.
The phosphate-containing flame retardants may be used alone or in combination of two or more.

<Antimony-containing flame retardant>
Examples of the antimony-containing flame retardant used in the present invention include antimony oxide, antimonate salts, and pyroantimonate salts.
Examples of antimony oxide include antimony trioxide and antimony pentoxide. Examples of antimonate salts include sodium antimonate, potassium antimonate, and the like. Examples of the pyroantimonate include sodium pyroantimonate, potassium pyroantimonate, and the like.
Preferably, the antimony-containing flame retardant is antimony oxide.
Antimony-containing flame retardants may be used alone or in combination of two or more.

<Phosphinic acid flame retardant>
Examples of phosphinic acid flame retardants include phosphinic acid, dimethylphosphinic acid, methylethylphosphinic acid, methylpropylphosphinic acid, diethylphosphinic acid, dioctylphosphinic acid, phenylphosphinic acid, diethylphenylphosphinic acid, diphenylphosphinic acid, bis( Examples include 4-methoxyphenyl)phosphinic acid.

<Metal hydroxide flame retardant>
Examples of metal hydroxide flame retardants include magnesium hydroxide, calcium hydroxide, aluminum hydroxide, iron hydroxide, nickel hydroxide, zirconium hydroxide, titanium hydroxide, zinc hydroxide, copper hydroxide, and hydroxide. Examples include vanadium and tin hydroxide. The metal hydroxide flame retardants may be used alone or in combination of two or more.

Examples of solid flame retardants other than the solid flame retardants mentioned above include phosphazene, phosphinate metal salts, silicone flame retardants, and organic sulfonate flame retardants.

The content of the solid flame retardant in the foamable urethane resin composition is not particularly limited, but is preferably 1 part by mass or more and 10 parts by mass or less based on 100 parts by mass of the urethane resin. By setting the content of the solid flame retardant to 1 part by mass or more, the flame retardancy of the polyurethane foam is enhanced and the foam is less likely to deform when exposed to heat. Furthermore, by controlling the content of the solid flame retardant to 10 parts by mass or less, the foamability of the foamable urethane resin composition becomes good, and the polyurethane foam formed is less likely to buckle, resulting in excellent handling properties. From this point of view, the content of the solid flame retardant is preferably 1.5 parts by mass or more, more preferably 2 parts by mass or more, based on 100 parts by mass of the urethane resin.

Examples of the liquid flame retardant include phosphoric acid ester flame retardants such as monophosphoric acid ester and condensed phosphoric acid ester.
Examples of the monophosphate ester include, but are not limited to, trimethyl phosphate, triethyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, tris(β-chloropropyl) phosphate, and the like.
Condensed phosphoric acid esters are not particularly limited, but include, for example, resorcinol polyphenyl phosphate (trade name: CR-733S), bisphenol A polycresyl phosphate (trade name: CR-741), aromatic condensed phosphoric acid esters (trade name: CR747). ), etc.
When using a liquid flame retardant, it is preferably 1 part by mass or more and 30 parts by mass or less, more preferably 5 parts by mass or more and 20 parts by mass or less, based on 100 parts by mass of the urethane resin.

<Inorganic filler>
The foamable urethane resin composition of the present invention may contain an inorganic filler as an additive to the extent that the effects of the present invention are not impaired. Examples of inorganic fillers include silica, diatomaceous earth, alumina, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, ferrites, basic magnesium carbonate, calcium carbonate, magnesium carbonate, barium carbonate, and dawsonite. , hydrotalcite, calcium sulfate, barium sulfate, gypsum fiber, potassium salts such as calcium silicate, talc, clay, mica, montmorillonite, bentonite, activated clay, sepiolite, imogolite, sericite, glass fiber, glass beads, silica parun, Aluminum nitride, boron nitride, silicon nitride, carbon black, graphite, carbon fiber, carbon parun, charcoal powder, various metal powders, potassium titanate, magnesium sulfate, lead zirconate titanate, aluminum porate, molybdenum sulfide, silicon carbide, stainless steel Examples include fibers, various magnetic powders, slag fibers, fly ash, silica alumina fibers, alumina fibers, silica fibers, and zirconia fibers.
From the viewpoint of foamability of the foamable urethane resin composition, the content of the inorganic filler is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, based on 100 parts by mass of the urethane resin. preferable.

The foamable urethane resin composition may further contain additives other than solid flame retardants, liquid flame retardants, and inorganic fillers, such as phenol-based, amine-based, sulfur-based antioxidants, and heat stabilizers. , metal damage inhibitors, antistatic agents, stabilizers, crosslinking agents, lubricants, softeners, pigments, additives such as tackifier resins, and tackifiers such as polybutene and petroleum resins.

(foam stabilizer)
The foamable urethane resin composition contains a foam stabilizer. Examples of the foam stabilizer include surfactants such as polyoxyalkylene foam stabilizers such as polyoxyalkylene alkyl ether, and silicone foam stabilizers such as organopolysiloxane. The silicone foam stabilizer may also include a graft copolymer of polydimethylsiloxane and polyethylene glycol.
The amount of the foam stabilizer in the foamable urethane resin composition is not particularly limited, but for example, it is preferably 0.01 to 3 parts by mass, and 0.05 to 2 parts by mass, based on 100 parts by mass of the urethane resin. It is more preferably 0.1 to 1 part by mass, and even more preferably 0.1 to 1 part by mass. Foam stabilizers may be used alone or in combination of two or more.

(foaming agent)
Specific examples of the blowing agent include water, low-boiling hydrocarbons, chlorinated aliphatic hydrocarbon compounds, fluorine compounds, hydrochlorofluorocarbon compounds, hydrofluorocarbons, ether compounds, hydrofluoroolefins, and the like. Further, examples of the blowing agent include organic physical blowing agents such as mixtures of these compounds, and inorganic physical blowing agents such as nitrogen gas, oxygen gas, argon gas, and carbon dioxide gas.
Examples of the low boiling point hydrocarbons include propane, butane, pentane, hexane, heptane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, and the like.
Examples of the chlorinated aliphatic hydrocarbon compound include dichloroethane, propyl chloride, isopropyl chloride, butyl chloride, isobutyl chloride, pentyl chloride, isopentyl chloride, and the like.
Examples of the fluorine compound include CHF ₃ , CH ₂ F ₂ , CH ₃ F, and the like.
Examples of the hydrochlorofluorocarbon compounds include trichloromonofluoromethane, trichlorotrifluoroethane, dichloromonofluoroethane (for example, HCFC141b (1,1-dichloro-1-fluoroethane), HCFC22 (chlorodifluoromethane), HCFC142b ( Examples include 1-chloro-1,1-difluoroethane)).
Examples of the hydrofluorocarbon include HFC-245fa (1,1,1,3,3-pentafluoropropane) and HFC-365mfc (1,1,1,3,3-pentafluorobutane).
Examples of the ether compound include diisopropyl ether.
Examples of the hydrofluoroolefins include HFO-1233zd(E) (trans-1-chloro-3,3,3-trifluoropropene), HFO-1234yf (2,3,3,3-tetrafluoro-1- Propene), etc.

The content of the blowing agent is preferably 0.1 to 30 parts by weight, more preferably 0.5 to 20 parts by weight, and even more preferably 1 to 15 parts by weight, based on 100 parts by weight of the urethane resin.

(catalyst)
The foamable urethane resin composition of the present invention contains a catalyst. The catalyst may contain, for example, one or both of a urethanization catalyst and a trimerization catalyst, and preferably contains both.

The urethanization catalyst is a catalyst that promotes the reaction between the polyol component and the polyisocyanate. Specific examples include amino compounds, tin compounds, bismuth compounds, and acetylacetone metal salts.
Examples of the amino compound include pentamethyldiethylenetriamine, triethylamine, N-methylmorpholine bis(2-dimethylaminoethyl)ether, bis(2-dimethylaminoethyl)ether, N,N,N',N",N" -pentamethyldiethylenetriamine, N,N,N'-trimethylaminoethyl-ethanolamine, bis(2-dimethylaminoethyl)ether, N-methyl-N',N'-dimethylaminoethylpiperazine, second in imidazole ring imidazole compounds in which the primary amine functional group is substituted with a cyanoethyl group, N,N-dimethylcyclohexylamine, diazabicycloundecene, triethylenediamine, tetramethylethylenediamine, tetramethylhexamethylenediamine, 1-methylimidazole, trimethylaminoethylpiperazine, Examples include tripropylamine.
Further, examples of the tin compound include stannous octylate, dibutyltin diacetate, dibutyltin dilaurate, and the like. Examples of the bismuth compound include bismuth neodecanoate and bismuth octylate.
Examples of acetylacetone metal salts include acetylacetone aluminum, acetylacetone iron, acetylacetone copper, acetylacetone zinc, acetylacetone beryllium, acetylacetone chromium, acetylacetone indium, acetylacetone manganese, acetylacetone molybdenum, acetylacetone titanium, acetylacetone cobalt, acetylacetone vanadium, acetylacetone zirconium, and the like. .
The urethane resin curing catalyst may be used alone or in combination of two or more.

There is no particular limitation on the amount of the urethanization catalyst in the foamable urethane resin composition, but it is preferably in the range of 0.3 to 10 parts by weight, and 0.5 to 8 parts by weight, based on 100 parts by weight of the urethane resin. The amount is more preferably in the range of 1 part by mass, and even more preferably in the range of 1 to 6 parts by mass. By setting it within the above range, the reaction between the polyol component and the polyisocyanate component can be promoted at an appropriate reaction rate.

A trimerization catalyst is a catalyst that promotes trimerization to form isocyanurate bonds. Polyurethane resin improves the flame retardancy of polyurethane foam by promoting trimerization.
Examples of trimerization catalysts include aromatic compounds such as tris(dimethylaminomethyl)phenol, 2,4-bis(dimethylaminomethyl)phenol, 2,4,6-tris(dialkylaminoalkyl)hexahydro-S-triazine, and acetic acid. Alkali metal salts such as potassium, sodium acetate, potassium 2-ethylhexanoate, sodium 2-ethylhexanoate, potassium octylate, sodium octylate, aziridines such as 2-ethylaziridine, lead naphthenate, lead octylate, etc. Lead compounds, alcoholate compounds such as sodium methoxide, phenolate compounds such as potassium phenoxide, tertiary ammonium salts such as trimethylammonium salt, triethylammonium salt, triphenylammonium salt, tetramethylammonium salt, tetraethylammonium, tetraphenylammonium salt, etc. A quaternary ammonium salt of, etc. can be used.
The trimerization catalyst may be used alone or in combination of two or more.

The blending amount of the trimerization catalyst is not particularly limited, but it is preferably in the range of 0.5 to 12 parts by mass, more preferably in the range of 1 to 9 parts by mass, based on 100 parts by mass of the urethane resin. More preferably, the amount is in the range of 2 to 5 parts by mass. By controlling the amount of trimerization catalyst within the above range, isocyanurate bonds are appropriately formed and flame retardancy is improved.
In addition, the total amount of the catalyst is preferably 0.5 to 15 parts by mass, more preferably 1 to 12 parts by mass, based on 100 parts by mass of the urethane resin, from the viewpoint of improving the curing speed and flame retardance of the urethane. More preferably 2 to 10 parts by mass.

Since the foamable urethane resin composition of the present invention is cured by the reaction between the polyol compound and the polyisocyanate compound, its viscosity changes with time. Therefore, before using the foamable urethane resin composition, the foamable urethane resin composition is divided into two or more parts to prevent the foamable urethane resin composition from reacting and curing. When using the foamable urethane resin composition, it is preferable to combine the foamable urethane resin composition, which has been divided into two or more parts, into one.

Note that when dividing the foamable urethane resin composition into two or more parts, each component of the foamable urethane resin composition divided into two or more parts does not start curing alone, and each component of the foamable urethane resin composition is divided into two or more parts. Each component may be separated so that the curing reaction begins after mixing. Usually, a foamable urethane resin composition is divided into a polyol composition containing a polyol compound and a polyisocyanate composition containing a polyisocyanate compound.

The foam stabilizer, foaming agent, catalyst, and additive described above may be contained in the polyol composition, may be contained in the polyisocyanate composition, or may be contained in the polyol composition and the polyisocyanate composition. may be provided separately, but is preferably contained in the polyol composition.

The method for producing the foamable urethane resin composition is not particularly limited, but includes a method in which a polyol composition and a polyurethane composition are prepared by kneading in advance and kneaded together, and a method of forming the foamable urethane resin composition. Examples include a method of kneading each component, but it is usually produced by kneading a polyol composition and a polyisocyanate composition. Kneading can be performed by a known method, for example, by using a known device such as a single screw extruder, twin screw extruder, Banbury mixer, kneader mixer, kneading roll, Raikai machine, planetary stirrer, etc. This can be obtained by

(Viscosity of polyol composition)
The viscosity of the polyol composition at 20° C. is not particularly limited, but is preferably 2000 mPa·s or less, and preferably 1000 mPa·s or less. By setting the viscosity of the polyol liquid agent to the above upper limit value or less, the fluidity of the foamable urethane resin composition also becomes good, and poor mixing and the like can be suppressed. The viscosity of the polyol composition can be adjusted as appropriate by, for example, the molecular weight of the polyol compound used. Note that the viscosity of the polyol composition was measured at a temperature of 20° C. using a B-type viscometer.

(Application)
The use of the foamable urethane resin composition of the present invention is not particularly limited, but may be used to fill cavities in structures such as buildings, furniture, automobiles, trains, ships, etc., or sprayed onto such structures. It can be used for Among these, it is preferable to use the composition for spraying onto structures, that is, as a foamable urethane resin composition for spraying.
Spraying can be carried out using a spraying device (for example, A-25 manufactured by GRACO) and a spray gun (for example, D-gun manufactured by Gasmer). Spraying can be carried out by adjusting the temperature of the polyol composition and polyisocyanate composition contained in separate containers in a spraying device, colliding and mixing them at the tip of a spray gun, and turning the mixed liquid into a mist using air pressure. Spraying devices and spray guns are well known and commercially available products can be used.

[Polyurethane foam]
The polyurethane foam of the present invention is formed from the above-described foamable urethane resin composition, and specifically, is obtained by foaming and curing the foamable urethane resin composition.
The polyurethane foam has a steel ball sinking distance of 20 mm or less in steel ball sinking evaluation. If the sinking distance of the steel ball exceeds 20 mm, the polyurethane foam is likely to catch fire when exposed to fire, making it difficult to effectively prevent the spread of fire. From the viewpoint of effectively preventing the spread of fire, the sinking distance of the steel ball is preferably 15 mm or less, more preferably 10 mm or less, and still more preferably 5 mm or less. Note that the sinking distance of the steel ball is 0 mm or more. The steel ball sinkage evaluation method is as described above. Incidentally, fires caused by polyurethane foam are largely caused by sparks and fireballs (heated iron lumps) during welding and fusing. According to the findings of the present inventors, in particular, when a fireball comes into contact with polyurethane foam, it progresses inside while melting the resin, and as a result, it has been found that there is a risk of ignition and fire spread from inside the polyurethane foam. did. The steel ball sinking evaluation described above reproduces and evaluates fires caused by polyurethane foam during welding and fusing, and can evaluate whether polyurethane foam is difficult to spread.

The density of the polyurethane foam is not particularly limited, but is preferably in the range of 20 to 200 kg/m ³ . By setting the density to 200 kg/m ³ or less, the polyurethane foam becomes lightweight and can be easily applied to structures. Moreover, by setting it as 20 kg/m ^<3> or more, it becomes easy to express desired flame retardancy. From these viewpoints, the density of the polyurethane foam is more preferably in the range of 25 to 100 kg/m ³ , even more preferably in the range of 25 to 80 kg/m ³ . The density of polyurethane foam can be measured in accordance with JIS K7222.

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

Details of each component used in each Example and Comparative Example are as follows.
(1) Polyol compound/p-phthalic acid polyester polyol (manufactured by Kawasaki Kasei Kogyo Co., Ltd., product name: Maximol RFK-505, hydroxyl value = 250 mgKOH/g)
・O-phthalic acid polyester polyol (manufactured by Kawasaki Kasei Kogyo Co., Ltd., product name: Maximol RDK-133, hydroxyl value = 315 mgKOH/g)
・Amine-based polyether polyol (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., product name: DK3776, hydroxyl value = 350 mgKOH/g)
・Ethylenediamine-based polyether polyol (manufactured by AGC Co., Ltd., product name: EXCENOL 750ED, hydroxyl value = 760 mgKOH/g
(2) Additive (red phosphorus (flame retardant))
・Red phosphorus (Rin Kagaku Kogyo, product name: Nova Excel 140)
(3) Additives (flame retardants other than red phosphorus)
(i) Solid flame retardant - zinc borate (manufactured by Hayakawa Shoji Co., Ltd., product name: Firebrake ZB)
- Brominated flame retardant <ethylene bis (pentabromophenyl)> (manufactured by Albemarle Japan Co., Ltd., product name: SAYTEX8010)
(ii) Liquid flame retardant/phosphate ester flame retardant <tris (β-chloropropyl) phosphate> (manufactured by Daihachi Kagaku Co., Ltd., product name: TMCPP)
(4) Foam stabilizer/polyalkylene glycol foam stabilizer (manufactured by Dow Corning Toray, product name: SH-193)
(5) Catalyst (i) Trimerization catalyst/quaternary ammonium salt (manufactured by Tosoh Corporation, product name: TOYOCAT TR20)
(ii) Urethane catalyst/imidazole compound (manufactured by Tosoh Corporation, product name: TOYOCAT DM70)
・Bismuth compound, (manufactured by Nitto Kasei Co., Ltd., product name: Neostan U600)
(6) Foaming agent/water/HFO-1233zd <hydrofluoroolefin> (manufactured by Honeywell, product name: Solstice LBA)
(7) Polyisocyanate compound/MDI (manufactured by Sumika Cobestrowrethane Co., Ltd., product name: 44V-20)

The measurement methods for each physical property and property are as follows.

[Steel ball sinking evaluation]
Regarding the polyurethane foams produced in each Example and Comparative Example, the sinking distance of the steel ball was measured according to the following steps (1) to (3).
(1) A polyurethane foam was cut into a cube of 50 mm on each side to prepare a test piece.
(2) Place a wire mesh at a point 30 mm from the burner mouth of a Bunsen burner (outer flame length 70 mm), place a steel ball with a diameter of 4.7 mm and a weight of 0.44 g on the wire mesh, and the entire steel ball turns red. The steel ball was heated for 7 minutes until the temperature changed, and the measured temperature of the steel ball was 770°C. Note that the Bunsen burner used LPG combustion gas.
(3) In an atmosphere of 23° C., the steel ball heated in (2) above was immediately placed on the center of the upper part of the test specimen in (1) above and left until sinking of the steel ball was completed. Next, the cross section of the test specimen was sufficiently cooled by standing at 23° C. for 30 minutes, and the sinking distance of the steel ball was measured.
Note that a cavity was formed in the test specimen from the top to the inside due to the sinking of the steel ball. The sinking distance of the steel ball means the maximum distance of the cavity in the direction perpendicular to the top surface of the test specimen.
Based on the sinking distance of the steel balls obtained, the quality of preventing the flame from spreading was judged as follows.
◎...The sinking distance of the steel ball is 0 mm or more and 10 mm or less ○...The sinking distance of the steel ball is more than 10 mm and 20 mm or less ×...The sinking distance of the steel ball is more than 20 mm

[Total calorific value]
The total calorific value of the polyurethane foam produced in each Example and Comparative Example was evaluated by the following method. In a polypropylene beaker, a mixture obtained by mixing a polyol compound, a flame retardant, a foam stabilizer, a catalyst, and a blowing agent with the composition shown in Table 1 and a polyisocyanate compound (total amount 200 g, liquid temperature 10 ° C.) were added. Pour in and stir with a lab body spar for 3 seconds. Immediately thereafter, the mixture was spread onto a gypsum board with a thickness of 12.5 mm to obtain a polyurethane foam. A polyurethane foam adhered to a gypsum board as a base was cut into pieces 10 cm long, 10 cm wide, and 3.25 cm thick (inner gypsum board 12.5 mm) to prepare a sample for a cone calorimeter test. Using a corn calorimeter test sample, measure the total calorific value after 5 minutes by the corn calorimeter test when heated for 5 minutes at a radiant heat intensity of 50 kW/m ² in accordance with the ISO-5660 test method. did.
[Shape deformation]
The shape of the cone calorimeter test sample used to measure the above gross calorific value after 5 minutes was visually observed and evaluated based on the following criteria.
〇...The shape deformation of the sample in the thickness direction and width direction is small. In particular, there is no contact with the spark igniter in the thickness direction.
Δ: The shape deformation of the sample in the width direction is small, but it is slightly large in the thickness direction.

×: It can be determined that the shape deformation of the sample in the thickness direction and width direction is large and harmful in terms of fire prevention.

[Example 1]
According to the formulation in Table 1, the polyol compound, flame retardant (red phosphorus and flame retardant other than red phosphorus), foam stabilizer, catalyst, and blowing agent were weighed into a 1000 mL polypropylene beaker, stirred at 20°C for 10 seconds with a hand mixer, and the polyol compound was added. A composition was prepared. Thereafter, a polyisocyanate composition (polyisocyanate compound) whose temperature was also controlled at 10°C was added to the polyol composition cooled to 10°C to obtain a foamable urethane resin composition, and the composition was stirred for 3 seconds with a lab body spar. Then, a polyurethane foam was produced. Using the polyurethane foam, the steel ball sinking evaluation described above was performed. Further, the total calorific value and shape deformation were also evaluated using the above-described procedures.
Various evaluation results are shown in Table 1.

[Examples 2 to 9, Comparative Examples 1 to 2]
A polyurethane foam was obtained in the same manner as in Example 1, except that the formulation was changed as shown in Table 1. Using the polyurethane foam, the steel ball sinking evaluation described above was performed. Further, the total calorific value and shape deformation were also evaluated using the above-described procedure.
Various evaluation results are shown in Table 1.

As shown in each example, the polyurethane foam formed from the foamable urethane resin composition of the present invention was found to have a property of being difficult to spread due to the short sinking distance of the steel ball. . Furthermore, since the polyurethane foam did not contain red phosphorus, the dark red coloration characteristic of red phosphorus was not observed.
On the other hand, since the polyurethane foam formed from the foamable urethane resin composition of the comparative example contains red phosphorus, the dark red coloring characteristic of red phosphorus was confirmed, or the steel balls It was found that the sinking distance was long and that it did not have properties that would prevent it from spreading.

Claims (6)

A foamable urethane resin composition containing a polyol compound, a polyisocyanate compound, a foam stabilizer, a blowing agent, a catalyst, and an additive,
The foamable urethane resin composition does not substantially contain red phosphorus,
the polyol compound includes an aromatic polyol compound,
the blowing agent includes a hydrofluoroolefin;
The catalyst contains a urethanization catalyst and a trimerization catalyst, the urethanization catalyst contains an imidazole compound and a bismuth compound, and the trimerization catalyst contains a quaternary ammonium salt,
The additive includes a solid flame retardant and a liquid flame retardant, and the solid flame retardant is at least one selected from boron-containing flame retardants, bromine-containing flame retardants, and antimony-containing flame retardants,
The content of the solid flame retardant is 1 part by mass or more and 10 parts by mass or less based on 100 parts by mass of the urethane resin consisting of a polyol compound and a polyisocyanate compound,
The content of the liquid flame retardant is 1 part by mass or more and 20 parts by mass or less based on 100 parts by mass of urethane resin consisting of a polyol compound and a polyisocyanate compound,
A foamable urethane resin composition having a steel ball sinking distance of 20 mm or less in the following steel ball sinking evaluation of a polyurethane foam made of the foamable urethane resin composition.
(Steel ball sinking evaluation)
(1) A polyurethane foam is cut into a cube with each side of 50 mm and used as a test piece.
(2) Place a wire mesh at a point 30 mm from the burner mouth of a Bunsen burner (outer flame length 70 mm), place a steel ball with a diameter of 4.7 mm and a weight of 0.44 g on the wire mesh, and the entire steel ball turns red. Heat the steel ball for at least 5 minutes or more until the steel ball temperature changes to 750°C or higher.
(3) In an atmosphere of 23° C., immediately place the steel ball heated in (2) above on the center of the upper part of the test specimen in (1) above, and leave it until the steel ball sinks completely. Next, a cross section of the sufficiently cooled test specimen is cut to measure the sinking distance of the steel ball. When the polyurethane foam made of the foamable urethane resin composition is heated at a radiant heat intensity of 50 kW/ ^m2 in accordance with the ISO-5660 test method, the total calorific value after 5 minutes is 8 MJ/m2. The foamable urethane resin composition according to claim 1, which has a particle size of m ² or less. The foamable urethane resin composition according to claim 1 or 2 , having an isocyanate index of 200 to 700. The foamable urethane resin composition according to any one of claims 1 to 3 , which is a foamable urethane resin composition for spraying. Further, the flame retardant contains at least one selected from phosphate-containing flame retardants, phosphinic acid flame retardants, and metal hydroxide flame retardants, according to any one of claims 1 to 4 . foamable urethane resin composition. A polyurethane foam formed from the expandable urethane resin composition according to any one of claims 1 to 5 , wherein the steel ball sinking distance in the steel ball sinking evaluation is 20 mm or less.