JP7850033B2 - Polyol composition - Google Patents

Description

This invention relates to polyol compositions.

Polyurethane foam, due to its excellent thermal insulation and adhesive properties, is used as insulation material in buildings such as apartment buildings, detached houses, various school facilities, and commercial buildings. Polyurethane foam is obtained by mixing a polyol composition with isocyanate, foaming the mixture, and then spraying it onto objects such as ceilings, walls, and roofs using a spray device.

It is known that polyol compositions contain fillers to adjust various physical properties of polyurethane foam, such as flame retardancy. However, when polyol compositions containing fillers are stored for a long period of time, the fillers may settle and solidify to the point where they cannot be re-mixed, a phenomenon known as hard caking.
From the viewpoint of suppressing such hard caking, Patent Document 1 proposes incorporating metal oxide fine particles having hydrophobic groups on their surface into the polyol composition.

Patent No. 7029338

As described above, hard caking is suppressed by incorporating metal oxide nanoparticles having hydrophobic groups on their surface into the polyol composition. However, the viscosity of the polyol composition tends to increase with the incorporation of metal oxide nanoparticles, and therefore there was room for improvement from the standpoint of workability.
Therefore, the present invention aims to provide a polyol composition that can suppress hard caking and has low viscosity.

As a result of diligent research, the inventors have discovered that the above problems can be solved by a specific polyol composition containing at least a filler comprising metal oxide fine particles having hydrophobic groups on their surface and a bromine-based filler in which two aromatic rings are bonded to both ends of a linking group having a linear hydrocarbon structure with two or more carbon atoms. Thus, the present invention was completed. That is, the present invention provides the following [1] to [12].

[1] A polyol composition comprising a polyol, a filler, a blowing agent, a catalyst, and a nucleophilic inhibitor, wherein the filler comprises at least metal oxide fine particles having hydrophobic groups on its surface and a bromine-based filler in which a group having two aromatic rings is bonded to both ends of a linking group having a linear hydrocarbon structure with two or more carbon atoms.
[2] The polyol composition according to [1] above, wherein the filler contains a solid flame retardant.
[3] The polyol composition according to [1] or [2] above, wherein the metal oxide fine particles are metal oxide fine particles whose surface has been hydrophobized.
[4] The polyol composition according to any one of [1] to [3] above, wherein the content of the bromine-based filler is 3 to 40 parts by mass per 100 parts by mass of polyol.
[5] The polyol composition according to any one of [1] to [4] above, wherein the content of the metal oxide fine particles is 0.5 to 4 parts by mass per 100 parts by mass of polyol.
[6] The polyol composition according to any one of [1] to [5] above, wherein the bromine-based filler is ethylenebis(pentabromophenyl).
[7] The polyol composition according to any one of [1] to [6] above, wherein the nucleophilic inhibitor is magnesium hydroxide.
[8] The polyol composition according to any one of [1] to [7] above, wherein the catalyst comprises a trimerizing catalyst.
[9] The polyol composition according to [8], wherein the trimerizing catalyst contains a quaternary ammonium salt.
[10] The polyol composition according to any one of [1] to [9] above, wherein the catalyst comprises a urethane catalyst.
[11] The polyol composition according to [10], wherein the urethane catalyst comprises an imidazole derivative.
[12] The polyol composition according to [10] or [11], wherein the urethane catalyst comprises at least one metal catalyst selected from bismuth-containing compounds and tin-containing compounds.

According to the present invention, it is possible to provide a polyol composition that can suppress hard caking and has low viscosity.

The polyol composition of the present invention comprises a polyol, a filler, a foaming agent, a catalyst, and a nucleophilic inhibitor, wherein the filler includes at least metal oxide fine particles having hydrophobic groups on its surface and a bromine-based filler in which two aromatic rings are bonded to both ends of a linking group having a linear hydrocarbon structure with two or more carbon atoms.

<Filler>
The filler in the present invention comprises at least metal oxide fine particles having hydrophobic groups on their surface, and a bromine-based filler in which a group having two aromatic rings is bonded to both ends of a linking group having a linear hydrocarbon structure with two or more carbon atoms. The bromine-based filler in which a group having two aromatic rings is bonded to both ends of a linking group having a linear hydrocarbon structure with two or more carbon atoms may also be simply referred to as a bromine-based filler.

(Bromine-based fillers)
The polyol composition of the present invention contains a bromine-based filler in which a group having two aromatic rings is bonded to both ends of a linking group having a linear hydrocarbon structure with two or more carbon atoms. By containing this bromine-based filler in the polyol composition, the viscosity increase caused by the incorporation of metal oxide fine particles, described later, can be suppressed, and the viscosity of the polyol composition can be kept low. As a result, the workability when forming polyurethane foam is improved. Furthermore, by containing the bromine-based filler in the polyol composition, hard caking is more easily suppressed.
The reason for this is not entirely clear, but it is presumed to be as follows: The bromine-based filler in this invention has a structure in which aromatic rings are bonded to both ends of a linking group having a linear hydrocarbon structure with two or more carbon atoms, and because it contains a bromine atom, it is a compound with significant steric hindrance. Therefore, it is thought that the bromine-based filler of this invention, with its significant steric hindrance, is inserted between compounds that cause aggregation (for example, fillers other than the bromine-based filler), thereby suppressing aggregation.

The bromine-based filler in this invention is represented by the following formula (A).
X ₁ -R-X ₂ formula (A)
In formula (A) above, R is a linking group having a linear hydrocarbon structure with 2 or more carbon atoms, and _X1 and _X2 are groups having an aromatic ring, which may be the same group or different groups. _X1 and _X2 are bonded to both ends of the linking group R, and more specifically, _X1 and _X2 are bonded to both ends of the linear hydrocarbon structure of R having 2 or more carbon atoms. In addition, at least one of _X1 and _X2 is a group having a bromine atom.

As for the linear hydrocarbon structure with 2 or more carbon atoms in R, a linear alkylene group with 2 to 8 carbon atoms is more preferred, a linear alkylene group with 2 to 4 carbon atoms is even more preferred, and a linear alkylene group with 2 carbon atoms (i.e., an ethylene group) is even more preferred. In R, some of the hydrogen atoms of these alkylene groups may be substituted with atoms other than hydrogen atoms and functional groups, for example, with alkyl groups such as methyl, ethyl, and propyl groups, but it is preferable that they are not substituted. In other words, R is preferably a linking group consisting of a linear hydrocarbon structure with 2 or more carbon atoms. From the viewpoint of reducing the viscosity of the polyol composition and suppressing hard caking, R is particularly preferably an ethylene group.

_X1 and _X2 are each groups having an aromatic ring. The groups having an aromatic ring may have an aromatic ring in part or may consist entirely of an aromatic ring. From the viewpoint of reducing the viscosity of the polyol composition and suppressing hard caking, it is preferable that _X1 and _X2 are each independently selected from a brominated phenyl group and a brominated phthalimide group.
Specifically, the bromine-based filler in the present invention is preferably at least one of the compounds represented by the following formula (A-1) and the compound represented by the following formula (A-2).

In formula (A-1), R is the same as R in formula (A) described above. _R3 to _R12 are each independently a hydrogen atom or a bromine atom, and at least one of _R3 to _R12 is a bromine atom. In particular, it is preferable that two or more of _R3 to _R12 are bromine atoms, more preferably four or more are bromine atoms, and even more preferably that all are bromine atoms.
In formula (A-2), R is the same as R in formula (A) described above. _R13 to _R20 are each independently a hydrogen atom or a bromine atom, and at least one of _R13 to _R20 is a bromine atom. In particular, it is preferable that two or more of _R13 to _R20 are bromine atoms, more preferably four or more are bromine atoms, and even more preferably that all are bromine atoms.

In this invention, the bromine-based filler is preferably at least one compound selected from ethylenebis(pentabromophenyl) and ethylenebis(tetrabromophthalimide), and more preferably ethylenebis(pentabromophenyl). Using such a bromine-based filler further improves the viscosity reduction and hard caking suppression effects of the polyol composition.

The bromine-based filler content is preferably 3 to 40 parts by mass, more preferably 5 to 35 parts by mass, and even more preferably 10 to 30 parts by mass, per 100 parts by mass of polyol. By setting the bromine-based filler content within the above range, it becomes easier to achieve a good balance between reducing the viscosity of the polyol composition and suppressing hard caking.

(metal oxide fine particles)
The polyol composition of the present invention contains metal oxide fine particles having hydrophobic groups on their surface (hereinafter also simply referred to as metal oxide fine particles). This makes it easier to prevent filler sedimentation and suppress the occurrence of hard caking when the polyol composition is stored for a long period of time.
In metal oxide nanoparticles having hydrophobic groups on their surface, examples of metal oxide nanoparticles include silicon dioxide, aluminum oxide, titanium dioxide, and zirconium oxide, with silicon dioxide being the most preferred among them.

The metal oxide nanoparticles in this invention have hydrophobic groups on their surface. Examples of such hydrophobic groups include alkylsilyl groups such as dimethylsilyl, trimethylsilyl, dimethylpolysiloxane, aminoalkylsilyl, methacrylatesilyl, and octylsilyl. Among these, dimethylsilyl and trimethylsilyl groups are preferred.

In the present invention, the metal oxide nanoparticles are preferably metal oxide nanoparticles whose surfaces have been hydrophobized. The hydrophobization treatment is carried out according to a conventional method. A specific example of the hydrophobization treatment is a method in which the hydroxyl groups of hydrophilic metal oxide nanoparticles having hydroxyl groups on their surface are hydrophobized with a hydrophobic agent.
Examples of hydrophobic agents used in hydrophobic treatment include monochlorosilanes such as chlorotrimethylsilane, dichlorosilanes such as dichlorodimethylsilane, alkylsilanes such as octylsilane, silicone oils such as dimethylpolysiloxane, hexamethyldisilazane, aminoalkylsilane, and methacrylicsilane.

The average primary particle size of the metal oxide nanoparticles is preferably 3 nm to 60 nm, more preferably 5 nm to 50 nm, and even more preferably 5 nm to 40 nm. The average primary particle size is best measured using a transmission electron microscope.
The specific surface area of the metal oxide fine particles is preferably 100 to 500 ^m² /g, more preferably 150 to 400 ^m² /g, and particularly preferably 200 to 350 ^m² /g. The specific surface area was measured by the BET method.

The content of metal oxide fine particles is preferably 0.5 to 4 parts by mass, and more preferably 1 to 3.5 parts by mass, per 100 parts by mass of polyol.

(Solid flame retardant)
The fillers contained in the polyol composition of the present invention may include a solid flame retardant as a filler other than the metal oxide fine particles and bromine-based fillers described above. Here, a solid flame retardant is a flame retardant that is solid at room temperature (25°C) and normal pressure (1 atm). The inclusion of a solid flame retardant improves the flame retardancy of the polyurethane foam formed.
Examples of solid flame retardants include red phosphorus-based flame retardants, boron-based flame retardants, phosphate-containing flame retardants, antimony-containing flame retardants, phosphinic acid-based flame retardants, and metal hydroxide-based flame retardants. Among these, red phosphorus-based flame retardants are preferred as solid flame retardants. From the viewpoint of improving flame retardancy, one type of solid flame retardant may be used alone, or two or more types may be used in combination.

(Red phosphorus-based flame retardant)
Red phosphorus-based flame retardants may be red phosphorus alone, red phosphorus coated with a resin, metal hydroxide, metal oxide, etc., or a mixture of red phosphorus and a resin, metal hydroxide, metal oxide, etc. The resin used to coat or mix with red phosphorus is not particularly limited, but examples include thermosetting resins such as phenolic resins, epoxy resins, unsaturated polyester resins, melamine resins, urea resins, aniline resins, and silicone resins. From the viewpoint of flame retardancy, metal hydroxides are preferred as the compound to be coated or mixed. The metal hydroxides described later may be appropriately selected and used.

(Boron-based flame retardant)
Examples of boron-based flame retardants include alkali metal borates such as lithium borate, sodium borate, potassium borate, and cesium borate; alkaline earth metal borates such as magnesium borate, calcium borate, and barium borate; zirconium borate, zinc borate, aluminum borate, and ammonium borate. Among these, zinc borate is preferred.

(Phosphate-containing flame retardant)
Examples of phosphate-containing flame retardants include phosphates comprising a salt of phosphoric acid with at least one metal or compound selected from metals of groups IA to IVB of the periodic table, ammonia, aliphatic amines, and aromatic amines.
While there are no specific limitations on phosphates, various types of phosphates can be mentioned, such as monophosphates, pyrophosphates, and polyphosphates.
Examples of metals from groups IA to IVB of the periodic table include lithium, sodium, calcium, barium, iron(II), iron(III), and aluminum. Examples of aliphatic amines include methylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, and piperazine. Examples of aromatic amines include pyridine, triazine, and melamine.
Furthermore, the above-mentioned phosphate-containing flame retardants may be subjected to known water-resistance-improving treatments, such as silane coupling agent treatment or coating with melamine resin.

Specific examples of phosphate-containing flame retardants include monophosphates, pyrophosphates, and polyphosphates.
The monophosphates are not particularly limited, but examples include ammonium salts such as ammonium phosphate, ammonium dihydrogen phosphate, and diammonium hydrogen phosphate; sodium salts such as monosodium phosphate, disodium phosphate, trisodium phosphate, monosodium phosphite, disodium phosphite, and sodium hypophosphite; potassium salts such as monopotassium phosphate, dipotassium phosphate, tripotassium phosphate, monopotassium phosphite, dipotassium phosphite, and potassium hypophosphite; lithium salts such as monolithium phosphate, dilithium phosphate, trilithium phosphate, monolithium phosphite, dilithium phosphite, and lithium hypophosphite; barium salts such as barium dihydrogen phosphate, barium hydrogen phosphate, tribarium phosphate, and barium hypophosphite; magnesium salts such as magnesium monohydrogen phosphate, magnesium hydrogen phosphate, trimagnesium phosphate, and magnesium hypophosphite; calcium salts such as calcium dihydrogen phosphate, calcium hydrogen phosphate, tricalcium phosphate, and calcium hypophosphite; and zinc salts such as zinc phosphate, zinc phosphite, and zinc hypophosphite.

Polyphosphates are not particularly limited, but examples include ammonium polyphosphate, piperazine polyphosphate, melamine polyphosphate, ammonium polyphosphate amide, and aluminum polyphosphate.
Among these, the use of monophosphate is preferable because it improves the self-extinguishing properties of the phosphate-containing flame retardant, and the use of ammonium dihydrogen phosphate is more preferable.
A single phosphate-containing flame retardant may be used, or two or more types may be used together.

(Antimony-containing flame retardant)
Examples of antimony-containing flame retardants used in the present invention include antimony oxide, antimony salts, and pyroantimony salts.
Examples of antimony oxides include antimony trioxide and antimony pentoxide. Examples of antimonate salts include sodium antimonate and potassium antimonate. Examples of pyroantimonate salts include sodium pyroantimonate and potassium pyroantimonate.
The antimony-containing flame retardant is preferably antimony oxide.
Antimony-containing flame retardants may be used individually or in combination of two or more types.

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

(Metal hydroxide-based flame retardant)
Examples of metal hydroxide-based flame retardants include magnesium hydroxide, calcium hydroxide, aluminum hydroxide, iron hydroxide, nickel hydroxide, zirconium hydroxide, titanium hydroxide, zinc hydroxide, copper hydroxide, vanadium hydroxide, and tin hydroxide. Metal hydroxide-based flame retardants may be used individually or in combination of two or more types.

The content of the solid flame retardant is preferably 5 to 100 parts by mass, more preferably 10 to 80 parts by mass, and even more preferably 20 to 50 parts by mass, per 100 parts by mass of polyol, from the viewpoint of improving flame retardancy and adjusting viscosity to a low level.

The amount of filler contained in the polyol composition is preferably 10 to 150 parts by mass, more preferably 15 to 120 parts by mass, and even more preferably 30 to 90 parts by mass, per 100 parts by mass of polyol.

<Nucleophilic inhibitors>
The polyol composition of the present invention contains a nucleophilic inhibitor. The electrophilic nucleophilic inhibitor acts on the catalyst in the polyol composition preferentially over the blowing agent or, if necessary, the flame retardant, and acts gently on the catalyst to the extent that the catalyst's activity is not impaired, thereby suppressing the reaction between the blowing agent and the catalyst, or between the flame retardant and the catalyst. Therefore, by including a nucleophilic inhibitor in the polyol composition, it is possible to suppress the reaction between the flame retardant, especially a metallic flame retardant, and the catalyst, or between the blowing agent and the catalyst, thereby maintaining the storage stability of the polyol composition and improving the workability when forming polyurethane foam.
While polyol compositions tend to have higher viscosity when nucleophilic inhibitors are included, the present invention, as described above, makes it possible to maintain low viscosity by using a specific bromine-based filler.

Examples of nucleophilic inhibitors used in the present invention include alkali metal compounds, alkaline earth metal compounds, and transition metal compounds.
Examples of alkali metal compounds used as nucleophilic inhibitors include alkali metal hydroxides, carbonates, and carboxylates. Examples of alkali metal hydroxides include lithium hydroxide, sodium hydroxide, and potassium hydroxide. Examples of alkali metal carbonates include lithium carbonate, sodium carbonate, and potassium carbonate. Examples of alkali metal carboxylates include alkali metal acetates such as lithium acetate, sodium acetate, and potassium acetate.

Examples of alkaline earth metal compounds include hydroxides, carbonates, and sulfates of alkaline earth metals. Examples of alkaline earth metal hydroxides include beryllium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, and barium hydroxide. Examples of alkaline earth metal carbonates include beryllium carbonate, magnesium carbonate, calcium carbonate, strontium carbonate, and barium carbonate. Examples of alkaline earth metal sulfates include beryllium sulfate, magnesium sulfate, calcium sulfate, strontium sulfate, and barium sulfate.
Examples of transition metal compounds include transition metal hydroxides. Examples of transition metal hydroxides include manganese(II) hydroxide, iron(II) hydroxide, iron(III) hydroxide, nickel(II) hydroxide, copper(II) hydroxide, zinc hydroxide, vanadium hydroxide, and chromium(III) hydroxide.

The nucleophilic inhibitor used in the present invention may be used alone or in combination of two or more types, but it is preferable to use one type alone.
Furthermore, as the nucleophilic inhibitor used in the present invention, at least one selected from the group consisting of alkali metal compounds and alkaline earth metal compounds is preferred. Among these, alkaline earth metal compounds are more preferred, and alkaline earth metal hydroxides are even more preferred, as they readily exhibit the effect of a nucleophilic inhibitor.
Furthermore, preferred nucleophilic inhibitors include magnesium hydroxide, lithium hydroxide, sodium acetate, potassium carbonate, calcium carbonate, barium sulfate, and copper(II) hydroxide, with magnesium hydroxide being particularly preferred among them.

The content of the nucleophilic inhibitor in the polyol composition of the present invention is preferably 0.2 to 80 parts by mass, more preferably 0.5 to 60 parts by mass, even more preferably 1 to 30 parts by mass, and particularly preferably 2 to 10 parts by mass, per 100 parts by mass of polyol. A content of the nucleophilic inhibitor above the lower limit reliably suppresses catalyst deactivation. On the other hand, a content of the nucleophilic inhibitor below the upper limit allows for appropriate maintenance of catalyst activity and also maintains a low viscosity of the polyol composition.

<Liquid Flame Retardant>
The polyol composition of the present invention may contain a liquid flame retardant. A liquid flame retardant is one that is liquid at room temperature (25°C) and normal pressure (1 atm). The liquid flame retardant is not particularly limited, but a phosphate ester-based flame retardant is preferred.

As phosphate ester-based flame retardants, monophosphate esters, condensed phosphate esters, etc., can be used. A monophosphate ester is a phosphate ester containing one phosphorus atom in its molecule. Examples of monophosphate esters include trialkyl phosphates such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, and tri(2-ethylhexyl) phosphate; halogen-containing phosphate esters such as tris(β-chloropropyl) phosphate; trialkoxy phosphates such as tributoxyethyl phosphate; aromatic ring-containing phosphate esters such as tricresyl phosphate, trixylenyl phosphate, tris(isopropylphenyl) phosphate, cresyldiphenyl phosphate, and diphenyl(2-ethylhexyl) phosphate; and acidic phosphate esters such as monoisodecyl phosphate and diisodecyl phosphate.

Examples of condensed phosphate esters include aromatic condensed phosphate esters such as trialkyl polyphosphates, resorcinol polyphenyl phosphates, bisphenol A polycresyl phosphates, and bisphenol A polyphenyl phosphates.
Examples of commercially available condensed phosphate esters include "CR-733S,""CR-741," and "CR747" from Daihachi Chemical Industry Co., Ltd., and "ADEKA Stab PFR" and "FP-600" from ADEKA Corporation.

The phosphate ester flame retardants may be used individually from the above-mentioned types, or two or more may be used in combination. Among these, monophosphate esters are preferred from the viewpoint of easily adjusting the viscosity of the polyol composition and improving the flame retardancy of the polyurethane foam, and halogen-containing phosphate esters such as tris(β-chloropropyl) phosphate are more preferred.

The content of the liquid flame retardant in the polyol composition is not particularly limited, but is preferably 15 to 90 parts by mass, more preferably 20 to 80 parts by mass, and even more preferably 25 to 70 parts by mass, per 100 parts by mass of polyol. When the liquid flame retardant content is above these lower limits, it becomes easier to impart flame retardancy to the polyurethane foam without excessively increasing the viscosity of the polyol composition or excessively increasing the content of powders such as solid flame retardants. Furthermore, when the liquid flame retardant content is below these upper limits, foaming is not inhibited, making it easier to manufacture the polyurethane foam.

<Polyol>
The polyol composition of the present invention contains a polyol. Examples of polyols include polylactone polyols, polycarbonate polyols, polyester polyols, polymer polyols, and polyether polyols.

Examples of polylactone polyols include polypropiolactone glycol, polycaprolactone glycol, and polyvalerolactone glycol.
Examples of polycarbonate polyols include polyols obtained by the de-alcoholization reaction of hydroxyl group-containing compounds such as ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, octanediol, and nonanediol with ethylene carbonate, propylene carbonate, etc.

Examples of polyester polyols include polymers obtained by dehydrating and condensing a polybasic acid and a polyhydric alcohol, and condensates of hydroxycarboxylic acids and the aforementioned polyhydric alcohols.
Examples of polybasic acids include adipic acid, azelaic acid, sebacic acid, isophthalic acid (m-phthalic acid), terephthalic acid (p-phthalic acid), o-phthalic acid (phthalic acid), naphthalenedicarboxylic acid, and succinic acid. Examples of polyhydric alcohols include bisphenol A, ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, diethylene glycol, 1,6-hexane glycol, and neopentyl glycol.
Examples of hydroxycarboxylic acids include castor oil and reaction products of castor oil and ethylene glycol.

Examples of polymer polyols include polymers obtained by graft polymerization of ethylenically unsaturated compounds such as acrylonitrile, styrene, methyl acrylate, and methacrylate onto aromatic polyols, alicyclic polyols, aliphatic polyols, and polyester polyols, as well as polybutadiene polyols, or hydrogenated versions thereof.

Examples of polyether polyols include polymers obtained by ring-opening polymerization of at least one alkylene oxide having 2 to 6 carbon atoms, specifically ethylene oxide, propylene oxide, tetrahydrofuran, etc., in the presence of at least one low molecular weight active hydrogen compound having two or more active hydrogen atoms, such as a polyhydric alcohol. Examples of alkylene oxides include at least one of ethylene oxide and propylene oxide.
Examples of low molecular weight active hydrogen compounds having two or more active hydrogen atoms include bisphenol A, ethylene glycol, propylene glycol, butylene glycol, diols such as 1,6-hexanediol, triols such as glycerin and trimethylolpropane, tetrahydric to octahydric alcohols such as pentaerythritol, sorbitol, mannitol, sorbitan, diglycerin, dipentaerythritol, sucrose, glucose, mannose, fructose, methyl glucoside and its derivatives, phloroglucinol, and cresol. Examples include polyols such as pyrogallol, catechol, hydroquinone, bisphenol A, bisphenol F, bisphenol S, 1,3,6,8-tetrahydroxynaphthalene, and 1,4,5,8-tetrahydroxyanthracene; castor oil polyols; (co)polymers of hydroxyalkyl (meth)acrylates; polyfunctional polyols (e.g., 2 to 100 functional groups) such as polyvinyl alcohol; condensates of phenol and formaldehyde (novolac); ethylenediamine; and amines such as butylenediamine.
As the polyether polyol, a Mannich-type polyether polyol may be used. A Mannich-type polyether polyol is obtained using the Mannich reaction and is a Mannich condensate having two or more hydroxyl groups in the molecule, or a polyether polyol obtained by adding an alkylene oxide to such a Mannich condensate.

Polyols used in the present invention are preferably polyester polyols and polyether polyols. Polyols having two hydroxyl groups are also preferred. Among these, aromatic polyester polyols, which are polyester polyols having an aromatic ring, are preferred from the viewpoint of improving the flame retardancy of polyurethane foam.
The aromatic polyester polyol is preferably a condensate of an aromatic dicarboxylic acid such as o-phthalic acid (phthalic acid), m-phthalic acid (isophthalic acid), p-phthalic acid (terephthalic acid), or naphthalenedicarboxylic acid with a glycol. In particular, from the viewpoint of improving the flame retardancy of the polyurethane foam, especially its ability to prevent the spread of flame, the aromatic polyester polyol is more preferably a phthalic acid-based polyester polyol, which is a condensate of phthalic acid and glycol. Furthermore, it is even more preferable that the aromatic polyester polyol includes at least one selected from p-phthalic acid-based polyester polyol, which is a condensate of p-phthalic acid and glycol, and o-phthalic acid-based polyester polyol, which is a condensate of o-phthalic acid and glycol.

When the polyol contains an aromatic polyester polyol, the amount is not particularly limited, but is preferably 50 parts by mass or more, more preferably 70 parts by mass or more, even more preferably 80 parts by mass or more, and even more preferably 100 parts by mass, per 100 parts by mass of the polyol.

The weighted average hydroxyl value of the polyol is preferably 20 to 350 mg KOH/g, more preferably 50 to 300 mg KOH/g, and even more preferably 100 to 280 mg KOH/g. When the hydroxyl value of the polyol is below the upper limit, the viscosity of the polyol composition tends to decrease, which is preferable from the viewpoint of handling and other factors. On the other hand, when the hydroxyl value of the polyol is above the lower limit, the crosslinking density of the polyurethane foam increases, resulting in higher strength and better workability during spraying.
The hydroxyl value of polyols can be measured according to JIS K 1557-1:2007.

Here, the weighted average hydroxyl value of a polyol is determined by the sum of the products of the hydroxyl values of the individual polyols constituting the polyol and the weight fraction of each individual polyol in the polyol. For example, when using two types of polyols, (d1) and (d2), if the hydroxyl value of polyol (d1) is _X1 and the amount added is _m1 , and the hydroxyl value of polyol (d2) is _X2 and the amount added is _m2 , the weighted average hydroxyl value is expressed by the following formula. Note that the amounts _m1 and _m2 are parts by mass in 100 parts by mass of polyol.
Weighted average hydroxyl value (mgKOH/g) = X ₁ × (m ₁ / (m ₁ + m ₂ )) + X ₂ × (m ₂ / (m ₁ + m ₂ ))

<Foaming agent>
The polyol composition of the present invention contains a blowing agent. Specific examples of blowing agents include, for example, water, low-boiling hydrocarbons, chlorinated aliphatic hydrocarbon compounds, fluorine compounds, hydrochlorofluorocarbon compounds, hydrofluorocarbons, ether compounds, and hydrofluoroolefins. Furthermore, examples of blowing agents 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 hydrocarbons mentioned above include propane, butane, pentane, hexane, heptane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, and cycloheptane.
Examples of the above-mentioned chlorinated aliphatic hydrocarbon compounds include dichloroethane, propyl chloride, isopropyl chloride, butyl chloride, isobutyl chloride, pentyl chloride, and isopentyl chloride.
Examples of the fluorine compounds mentioned above include _CHF3 , _CH2F2 , _{and CH3F} .
Examples of the above-mentioned hydrochlorofluorocarbon compounds include trichloromonofluoromethane, trichlorotrifluoroethane, and dichloromonofluoroethane (for example, HCFC141b (1,1-dichloro-1-fluoroethane), HCFC22 (chlorodifluoromethane), and HCFC142b (1-chloro-1,1-difluoroethane)).
Examples of the above-mentioned hydrofluorocarbons include HFC-245fa (1,1,1,3,3-pentafluoropropane) and HFC-365mfc (1,1,1,3,3-pentafluorobutane).
Examples of the ether compounds mentioned above include diisopropyl ether.
Examples of the above-mentioned hydrofluoroolefins include HFO-1233zd(E) (trans-1-chloro-3,3,3-trifluoropropene), HFO-1234yf (2,3,3,3-tetrafluoro-1-propene), HFO-1336mzz(Z) (cis-1,1,1,4,4,4-hexafluorobuta-2-ene), and HFO-1224yd(Z).

Among the above, hydrofluoroolefins and water are preferred as foaming agents, and it is preferable to use hydrofluoroolefins and water in combination. As for the water used as a foaming agent, for example, ion-exchanged water or distilled water can be used as appropriate.

The amount of foaming agent is preferably 5 to 50 parts by mass, more preferably 10 to 45 parts by mass, and even more preferably 20 to 40 parts by mass, per 100 parts by mass of polyol, from the viewpoint of density adjustment.
When using hydrofluoroolefin as a foaming agent, the hydrofluoroolefin content is preferably 5 to 50 parts by mass, more preferably 10 to 45 parts by mass, and even more preferably 20 to 40 parts by mass, per 100 parts by mass of polyol.
When water is used as a foaming agent, the water content is preferably 0.1 to 5 parts by mass, more preferably 0.1 to 2.5 parts by mass, and even more preferably 0.5 to 2 parts by mass, per 100 parts by mass of polyol.

<Catalyst>
The polyol composition of the present invention contains a catalyst. The catalyst may contain a trimerizing catalyst, a urethane catalyst, or both a trimerizing catalyst and a urethane catalyst. In particular, it is preferable that the catalyst contains both a trimerizing catalyst and a urethane catalyst.

(trimerization catalyst)
The catalyst included in the polyol composition of the present invention preferably contains a trimerizing catalyst. The trimerizing catalyst is a catalyst that reacts with the isocyanate groups contained in the polyisocyanate (described later) to trimerize them and promote the formation of an isocyanurate ring. The advantage of including a trimerizing catalyst is that a good polyurethane foam can be obtained by completing the reaction of unreacted isocyanate groups. Examples of trimerizing catalysts include metal catalysts and ammonium salts. Among these, the trimerizing catalyst preferably contains an ammonium salt, and more preferably contains a quaternary ammonium salt.
Examples of metal catalysts used as trimerization catalysts (trimerization metal catalysts) include potassium organic acids, preferably potassium octoates such as potassium 2-ethylhexanoate, potassium acetate, potassium propionate, potassium butanoate, potassium benzoate, and other potassium carboxylates having 2 to 8 carbon atoms.
As the ammonium salt, tertiary ammonium salts such as triethylammonium salt and triphenylammonium salt, and quaternary ammonium salts such as tetramethylammonium salt, tetraethylammonium salt, and tetraphenylammonium salt can be used, but among these, quaternary ammonium salts are preferred. The ammonium salt is, for example, an ammonium salt of a carboxylic acid. Examples of carboxylic acids in the ammonium salt include saturated fatty acids having 1 to 10 carbon atoms, preferably 2 to 8 carbon atoms. The hydrocarbon group of the saturated fatty acid may be linear or branched, but branching is preferred. Specific examples of carboxylic acids include 2-ethylhexanoic acid, 2,2-dimethylpropanoic acid, acetic acid, and formic acid, but among these, 2,2-dimethylpropanoic acid is preferred. The trimerization catalyst may be used alone or two or more may be used in combination.

The content of the trimerizing catalyst in the polyol composition is preferably 0.1 to 20 parts by mass, more preferably 1 to 16 parts by mass, and even more preferably 2 to 14 parts by mass, per 100 parts by mass of the polyol compound.

(Urethane catalyst)
Urethane catalysts are catalysts that promote the reaction between polyols and polyisocyanates.
The urethane catalyst preferably contains a metal catalyst (urethane metal catalyst). The inclusion of the metal catalyst facilitates the reaction between the polyol and the polyisocyanate. From the viewpoint of foaming properties, the urethane catalyst preferably contains at least one metal catalyst selected from the group consisting of bismuth-containing compounds and tin-containing compounds, and more preferably contains a bismuth-containing compound.

The above metal catalyst is preferably a metal salt selected from bismuth salts and tin salts, and more preferably a bismuth salt. The metal salt is preferably an organic acid metal salt, and more preferably a metal salt of a carboxylic acid having 5 or more carbon atoms. Having 5 or more carbon atoms in the carboxylic acid provides good stability against blowing agents, especially hydrofluoroolefins. Furthermore, from the viewpoint of catalytic activity, the number of carbon atoms in the carboxylic acid is preferably 18 or less, and more preferably 12 or less. The carboxylic acid is preferably an aliphatic carboxylic acid, and more preferably a saturated aliphatic carboxylic acid. The carboxylic acid may be linear or have a branched structure, but it is preferable to have a branched structure.
Specific examples of carboxylic acids include octyl acid, lauryl acid, versatic acid, pentanoic acid, and acetic acid, with octyl acid being preferred among these. In other words, the transition metal salt is preferably a metal salt of octyl acid. These carboxylic acids may be linear as described above, but they may also have a branched structure. An example of octyl acid having a branched structure is 2-ethylhexanoic acid.
Preferred metal salts of carboxylic acids include bismuth salts and tin salts of carboxylic acids, with bismuth salts of octic acid being particularly preferred. Alternatively, the metal salt of the carboxylic acid may be an alkyl metal carboxylic acid salt. For example, the tin salt of the carboxylic acid may be a dialkyltin carboxylic acid salt, and preferably a dioctyltin carboxylic acid salt.
Specific examples of metal salts of carboxylic acids include bismastrioctate, dioctyl tin versatate, dibutyl tin dilaurate, dioctyl tin dilaurate, and tin dioctylate, with bismastrioctate and dioctyl tin versatate being preferred, and bismastrioctate being more preferred.

The content of the above-mentioned metal catalyst is not particularly limited, but is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, and even more preferably 1 to 6 parts by mass, per 100 parts by mass of polyol.

The urethane catalyst preferably contains an imidazole derivative, and more preferably contains both the metal catalyst and the imidazole derivative.
Imidazole derivatives are less affected by hydrofluoroolefins and facilitate the reaction between polyols and polyisocyanates. Therefore, by including imidazole derivatives in addition to the metal catalysts mentioned above, the reactivity between the polyol and polyisocyanate is enhanced, resulting in even better foaming properties.
The imidazole derivative is preferably an imidazole in which the 1st and 2nd positions are independently substituted with alkyl groups having 8 or fewer carbon atoms, and the alkyl groups preferably have 6 or fewer carbon atoms, more preferably 4 or fewer carbon atoms. A suitable specific example of an imidazole derivative is represented by the following general formula (1).

(In general formula (1), ^R1 and ^R2 each independently represent an alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms.)

In general formula (1), ^R1 and ^R2 each independently represent an alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms. The alkyl group and alkenyl group may each be linear or have a branched structure.
Specific examples of alkyl groups include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, pentyl group, neopentyl group, isopentyl group, sec-pentyl group, hexyl group, heptyl group, octyl group, and the like.
Specific examples of alkenyl groups include vinyl, 1-propenyl, allyl, isopropenyl, 1-butenyl, 2-butenyl, pentenyl, hexenyl, heptenyl, and octenyl groups.
If the number of carbon atoms in the alkyl or alkenyl groups of ^R1 and ^R2 is greater than or equal to the lower limit, steric hindrance increases, making the reaction less susceptible to the effects of blowing agents such as hydrofluoroolefins, which is preferable. On the other hand, if the number of carbon atoms in the alkyl groups of ^R1 and ^R2 is less than or equal to the upper limit, steric hindrance does not increase excessively, allowing the reaction between the polyol and polyisocyanate to proceed rapidly, and resulting in good foaming properties.
From these viewpoints, ^R1 and ^R2 are each preferably alkyl groups having 1 to 6 carbon atoms, more preferably alkyl groups having 1 to 4 carbon atoms, and even more preferably methyl groups.

Examples of imidazole derivatives represented by general formula (1) include 1,2-dimethylimidazole, 1-ethyl-2-methylimidazole, 1-methyl-2-ethylimidazole, 1,2-diethylimidazole, and 1-isobutyl-2-methylimidazole. Among these, 1,2-dimethylimidazole and 1-isobutyl-2-methylimidazole are preferred from the viewpoint of improving catalyst activity in the presence of hydrofluoroolefins and promoting rapid reaction. Furthermore, 1,2-dimethylimidazole is even more preferred from the viewpoint of further enhancing stability.

The content of the imidazole derivative in the polyol composition is preferably 0.1 to 15 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 1.5 to 7 parts by mass, per 100 parts by mass of polyol. When the imidazole derivative content is above the lower limit, urethane bond formation is more likely to occur, the reaction proceeds rapidly, and foaming properties are good. On the other hand, when the imidazole derivative content is below the upper limit, the reaction rate is easier to control, which is preferable.

The content of the urethane catalyst in the polyol composition is preferably 0.2 to 25 parts by mass, more preferably 0.8 to 15 parts by mass, and even more preferably 3 to 20 parts by mass, per 100 parts by mass of polyol.

<Foam stabilizer>
The polyol composition of the present invention may contain a foam stabilizer. Suitable foam stabilizers include compounds having polar and non-polar portions within their molecule and exhibiting surfactant properties.
The foam stabilizer is not particularly limited, but examples include surfactants such as polyoxyalkylene foam stabilizers such as polyoxyalkylene alkyl ethers and silicone foam stabilizers such as organopolysiloxanes. As a silicone foam stabilizer, a graft copolymer of polyoxyalkylene glycol, which is a polymer of ethylene oxide or propylene oxide, and polydimethylsiloxane may also be used. Commercially available products can also be used, specifically foam stabilizers such as SH-193 (manufactured by Toray Dow Corning), B8467 (manufactured by Evonik), F501 (manufactured by Shin-Etsu Chemical Co., Ltd.), and SF-2937F (manufactured by Dow Toray).
When a foam stabilizer is used, the content of the foam stabilizer in the polyol composition is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 8 parts by mass, and even more preferably 0.5 to 5 parts by mass, per 100 parts by mass of polyol. The foam stabilizer may be used alone or two or more types may be used.

<Other ingredients>
The polyol composition in the present invention may, as necessary and without impairing the objectives of the present invention, contain one or more antioxidants such as phenolic, amine, and sulfur-based antioxidants, heat stabilizers, light stabilizers, metal damage inhibitors, antistatic agents, stabilizers, crosslinking agents, lubricants, softeners, pigments, dyes, etc.
There are no particular limitations on the method for producing the polyol composition of the present invention; for example, it can be produced by mixing each component.

<Polyisocyanate>
The urethane resin composition in the present invention contains the above-mentioned polyol composition and polyisocyanate.
As the polyisocyanate contained in the urethane resin composition, various polyisocyanate compounds such as aromatic, alicyclic, and aliphatic compounds having two or more isocyanate groups can be used. Preferably, liquid diphenylmethane diisocyanate (MDI) is used due to its ease of handling, rapid reaction, excellent physical properties of the resulting polyurethane foam, and low cost. Examples of liquid MDI include crude MDI (also called polymeric MDI). Specific commercially available liquid MDIs include "44V-10" and "44V-20" (manufactured by Sumika Covestro Urethane Co., Ltd.) and "Millionate MR-200" (manufactured by Nippon Polyurethane Industry Co., Ltd.). Alternatively, uretonimine-containing MDI (for example, "Millionate MTL" as a commercially available product: manufactured by Nippon Polyurethane Industry Co., Ltd.) may also be used. Furthermore, a polyisocyanate compound may be used that has been pre-treated to increase its affinity with polyols by reacting some of the isocyanate active groups within the polyisocyanate compound with a hydroxyl group-containing compound. In addition to liquid MDI, other polyisocyanates may be used in combination, and any polyisocyanate known in the field of polyurethanes can be used without limitation.

The isocyanate index of the urethane resin composition of the present invention is preferably 150 or higher, more preferably 200 or higher, and even more preferably 250 or higher, from the viewpoint of properly forming polyurethane foam and imparting good flame retardancy.
Furthermore, the isocyanate index of the urethane resin composition is preferably 800 or less, more preferably 600 or less, and even more preferably 500 or less. When the isocyanate index is below these upper limits, flame retardancy that is sufficiently commensurate with the manufacturing cost can be obtained.
The isocyanate index (INDEX) is calculated using the following method.

INDEX = Equivalents of polyisocyanate ÷ (Equivalents of polyol + Equivalents of water) × 100
Here,
Polyisocyanate equivalent = Number of polyisocyanates used × NCO content (%) × 100 / NCO molecular weight. Polyol equivalent = OHV × Number of polyols used ÷ Molecular weight of KOH, where OHV is the hydroxyl value of the polyol (mg KOH/g).
The equivalent amount of water = number of parts of water used × number of OH groups in water / molecular weight of water. In the above formula, the unit of the number of parts used is weight (g), the molecular weight of the NCO group is 42, the NCO content is the proportion of NCO groups in the polyisocyanate compound expressed as mass %, and for the sake of unit conversion in the above formula, the molecular weight of KOH is assumed to be 56100, the molecular weight of water is assumed to be 18, and the number of OH groups in water is assumed to be 2.

<Polyurethane foam>
The polyurethane foam in the present invention is formed from the above-described urethane resin composition, and more specifically, it is obtained by foaming and curing a urethane resin composition obtained by mixing a polyol composition and polyisocyanate. The polyol composition of the present invention used to form the polyurethane foam has suppressed hard caking as described above, making it easy to stir, and it has low viscosity and good workability.

[Application]
The polyol composition, urethane resin composition, and polyurethane foam formed from the present invention are not particularly limited in their applications, but can be used to fill cavities in structures such as buildings, furniture, automobiles, trains, and ships, or for spraying onto such structures. In particular, they are preferably used for spraying onto surfaces such as walls, ceilings, roofs, and floors, i.e., for spraying applications. Since the polyol composition of the present invention suppresses caking, when the composition is used for spraying applications, it mixes easily with polyisocyanate, resulting in good dispersibility of solid flame retardants and other components in the resulting polyurethane foam. Therefore, good flame retardancy is achieved.
Spraying can be carried out using a spraying device (e.g., GRACO A-25) and a spray gun (e.g., Gasmar D-gun). Spraying is performed by temperature-controlled mixing of the polyol composition and polyisocyanate in separate containers within the spraying device, causing them to collide and mix at the tip of the spray gun, and then atomizing the mixture using air pressure. The spraying device and spray gun are well-known and commercially available products can be used. Furthermore, the stock solution temperature settings and pressures can be the same as those for spraying polyurethane foam.

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

The details of each component used in each example and comparative example are as follows.
<Polyol>
A-1: p-phthalate-based polyester polyol (manufactured by Hitachi Chemical Co., Ltd., product name: SV-208, hydroxyl value = 235 mg KOH/g)
<Liquid Flame Retardant>
B-1: Phosphate ester-based flame retardant Tris(β-chloropropyl) phosphate (manufactured by Daihachi Chemical Co., Ltd., product name: TMCPP)

<Filler>
C-1: Ethylene-bis(pentabromophenyl) (manufactured by Albemarle, product name: SAYTEX 8010)
C-2: Ethylene-bis(tetrabromophthalimide) (manufactured by Albemarle, product name: BT93)
C-3: Tetrabromobisphenol A-bis(2,3-dibromo-2-methylpropyl ether) (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: Piroguard SR-130)
C-4: Dibenzyl (manufactured by Tokyo Chemical Industry Co., Ltd.)
C-5: Red phosphorus (manufactured by Phosphorus Chemical Industry Co., Ltd., product name: Nova Excel 140)
C-6: Ammonium polyphosphate (Clariant Corporation, product name: AP422)
C-7: Zinc borate (manufactured by Hayakawa Shoji Co., Ltd., product name: FirebrakeZB)
C-8: Hydrophobically treated silicon dioxide nanoparticles (manufactured by Nippon Aerosil Co., Ltd., product name: AEROSIL R976S)

C-1 and C-2 above correspond to "bromine-based fillers in which a group having two aromatic rings is bonded to both ends of a linking group having a linear hydrocarbon structure with two or more carbon atoms." C-5 to C-7 above correspond to "solid flame retardants." C-8 above corresponds to "metal oxide fine particles having hydrophobic groups on their surface."

<Foaming agent>
D-1: Trans-1-chloro-3,3,3-trifluoropropene (manufactured by Honeywell, product name: Solstice LBA)
D-2: Ion-exchanged water

<Trimerization catalyst>
E-1: Quaternary ammonium salt (manufactured by Evonik Japan, product name: DABCO TMR-7), concentration 45-55% by mass. E-2: Potassium 2-ethylhexanoate salt (manufactured by Evonik Japan, product name: K-15), concentration 70-80% by mass.

<Urethane catalyst>
F-1: 1,2-dimethylimidazole (manufactured by Kao Corporation, product name: Kaolizer No. 390), concentration 65-75% by mass
F-2: Bismuth 2-ethylhexanoate (manufactured by Nitto Chemical Co., Ltd., product name: Bi28), concentration 81-90% by mass

<Nucleophilic inhibitors>
G-1: Magnesium hydroxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name: Magnesium hydroxide)

[Examples 1-7, Comparative Examples 1-5]
Polyol compositions were prepared by mixing polyol, liquid flame retardant, filler, blowing agent, trimerizing catalyst, urethane catalyst, and nucleophilic inhibitor according to the formulations shown in Table 1. The polyol compositions prepared in each example and comparative example were evaluated as follows.

[viscosity]
The viscosity of the polyol composition was measured using a Type B viscometer under the following conditions: spindle LV-03, rotation speed 60 rpm, and temperature 25°C.

[Soft caking integral, hard caking integral]
450 g of the polyol composition was placed in a high-vessel container and centrifuged using a centrifuge at 500 rpm for 1520 min. The load was measured from above using a force gauge on the separated solid-liquid liquid. The integral over the load region of 2 N or less was defined as the "soft caking integral value," and the integral over the load region of 5 N to 20 N was defined as the "hard caking integral value." A relatively high soft caking value indicates that hard caking has been suppressed.

[judgement]
Based on the viscosity and soft caking integral values described above, the following criteria were used for evaluation.
◎: Viscosity is less than 700 mPa·s, and the soft caking value is greater than 1000.
○: Viscosity is less than 1000 mPa·s, and the soft caking value is greater than 900. (However, this excludes cases marked with ◎)
×: Viscosity is 1000 mPa·s or higher, or soft caking value is 900 or lower.

Note that the mass parts of each catalyst refer to the mass parts of the finished product.

The polyol compositions of each embodiment that satisfy the requirements of the present invention exhibited low viscosity and relatively high soft caking values, thereby suppressing hard caking.
In contrast, the polyol compositions of Comparative Examples 1 to 5, which did not contain specific bromine-based fillers or metal oxide fine particles, resulted in high viscosity or a tendency to form hard caking.

Claims (11)

A polyol composition comprising a polyol, a filler, a blowing agent, a catalyst, and a nucleophilic inhibitor,
The filler comprises at least metal oxide fine particles having hydrophobic groups on its surface, and a bromine-based filler in which a group having two aromatic rings is bonded to both ends of a linking group having a linear hydrocarbon structure with two or more carbon atoms .
A polyol composition in which the nucleophilic inhibitor is magnesium hydroxide, and the content of magnesium hydroxide is 0.2 to 80 parts by mass per 100 parts by mass of polyol, which is used by spraying it onto an object to be sprayed using a spraying device and a spray gun . The polyol composition according to claim 1, wherein the filler comprises a solid flame retardant. The polyol composition according to claim 1 or 2, wherein the metal oxide fine particles are metal oxide fine particles whose surface has been hydrophobized. The polyol composition according to claim 1 or 2, wherein the content of the bromine-based filler is 3 to 40 parts by mass per 100 parts by mass of polyol. The polyol composition according to claim 1 or 2, wherein the content of the metal oxide fine particles is 0.5 to 4 parts by mass per 100 parts by mass of polyol. The polyol composition according to claim 1 or 2, wherein the bromine-based filler is ethylenebis(pentabromophenyl). The polyol composition according to claim 1 or 2, wherein the catalyst comprises a trimerizing catalyst. The polyol composition according to claim 7 , wherein the trimerizing catalyst comprises a quaternary ammonium salt. The polyol composition according to claim 1 or 2, wherein the catalyst comprises a urethane catalyst. The polyol composition according to claim 9 , wherein the urethane catalyst comprises an imidazole derivative. The polyol composition according to claim 9 , wherein the urethane catalyst comprises at least one metal catalyst selected from bismuth-containing compounds and tin-containing compounds.