Polyol composition, foamable urethane resin composition, and polyurethane foam

Abstract

To provide a polyol composition that enables prevention of reduction in the expansion ratio of a polyurethane foam when a hydrofluoroolefin is employed as a blowing agent.SOLUTION: A polyol composition for obtaining a polyurethane foam by reacting with a polyisocyanate compound, the polyol composition comprises a polyol, a catalyst, a foaming agent, and a flame retardant, wherein the catalyst includes an ammonium carboxylate, and the carboxylic acid of the ammonium carboxylate includes 2 or fewer carbon atoms.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyol composition, a foamable urethane resin composition, and a polyurethane foam. [Background technology]

[0002] Taking advantage of their excellent heat insulating properties, polyurethane foams are used in practice for insulating and preventing condensation in building components such as ceilings, roofs, and walls of buildings such as apartment complexes, detached houses, commercial buildings, etc. Polyurethane foams are formed by spraying a flame-retardant urethane resin composition containing a polyol compound and a polyisocyanate compound onto the surface of each structure, followed by foaming and curing.

[0003] The raw materials for forming polyurethane foam may contain a trimerization catalyst to enhance the reactivity of isocyanurate bond formation, from the viewpoint of promoting the curing reaction at the interface of the structure when forming the polyurethane foam by, for example, spray application. For example, Patent Document 1 discloses a composition containing a trimerization catalyst, an organic metal phosphinate, red phosphorus, and the like, as a composition for polyurethane foams that has a low calorific value upon combustion and excellent self-extinguishing properties, and describes the use of a quaternary ammonium salt as the trimerization catalyst. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-54942 Summary of the Invention [Problem to be solved by the invention]

[0005] The use of a trimerization catalyst such as a quaternary ammonium salt improves the workability of spray application of polyurethane foam. However, when a blowing agent such as a hydrofluoroolefin (HFO) is present in the composition for forming the polyurethane foam, the catalyst is easily deactivated, which causes a problem of a decrease in the expansion ratio of the resulting polyurethane foam (i.e., an increase in density).

[0006] Therefore, an object of the present invention is to provide a polyol composition that can prevent a decrease in the expansion ratio of polyurethane foam even when a hydrofluoroolefin is used as a blowing agent. [Means for solving the problem]

[0007] As a result of extensive investigations, the present inventors have found that the above-mentioned problems can be solved by using, as a trimerization catalyst, an ammonium carboxylate salt in which the carboxylic acid contains two or less carbon atoms in a polyol composition containing a polyol, a catalyst, a blowing agent, and a flame retardant, and have completed the present invention.

[0008] That is, the present invention includes the following [1] to [9]. [1] A polyol composition for producing a polyurethane foam by reacting with a polyisocyanate compound, the polyol composition comprising a polyol, a catalyst, a blowing agent, and a flame retardant, the catalyst comprising an ammonium carboxylate salt, and the carboxylic acid of the ammonium carboxylate salt having 2 or less carbon atoms. [2] The polyol composition according to [1] above, wherein the ammonium carboxylate has at least two methyl groups bonded to a quaternary nitrogen atom. [3] The polyol composition according to the above [1] or [2], wherein the catalyst comprises an organic acid bismuth salt. [4] The polyol composition according to any one of the above [1] to [3], wherein the catalyst contains a heterocyclic compound having a nitrogen atom. [5] The polyol composition according to any one of the above [1] to [4], wherein the flame retardant contains a phosphorus-based compound. [6] A foamable urethane resin composition obtained by mixing the polyol composition according to any one of the above [1] to [5] with a polyisocyanate. [7] The foamable urethane resin composition according to [6] above, wherein the ratio of the foaming completion time to the curing time is 3 or more. [8] The foamable urethane resin composition according to [6] or [7] above, which has an isocyanate index of 250 or more. [9] A polyurethane foam formed by spray foaming the foamable urethane resin composition according to any one of [6] to [8] above. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a polyol composition that can prevent a decrease in the expansion ratio of polyurethane foam even when a hydrofluoroolefin is used as a blowing agent. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Polyol composition] The polyol composition of the present invention is a polyol composition for producing a polyurethane foam by reacting with a polyisocyanate compound, and contains a polyol, a catalyst, a blowing agent, and a flame retardant. Each component will be described in detail below.

[0011] <Catalyst> The polyol composition of the present invention contains a catalyst, which includes an ammonium carboxylate salt in which the carboxylic acid contains two or less carbon atoms (hereinafter, also referred to as an ammonium carboxylate salt having a specific structure). The polyol composition of the present invention, by containing such an ammonium carboxylate salt having a specific structure, can prevent a decrease in the expansion ratio of polyurethane foam even when a hydrofluoroolefin is used as a blowing agent. The reason for this is not clear, but it is presumed that the carboxylic acid has a structure containing two or less carbon atoms, so that foaming continues to a certain extent due to internal heat generation even after the catalyst is deactivated by the hydrofluoroolefin. The ammonium carboxylate having a specific structure functions as a trimerization catalyst that promotes the reaction of forming an isocyanurate bond, that is, the catalyst contained in the polyol composition contains a trimerization catalyst.

[0012] The ammonium carboxylate salt having a specific structure contained in the catalyst of the present invention is preferably a compound represented by formula (1). M + X - Formula (1) where M + is a quaternary ammonium cation, and X - is a carboxylate anion with two or fewer carbon atoms.

[0013] The quaternary ammonium cation M in formula (1) + is preferably of the following structure: [ka] In formula (1), R 1 ~R 4 are substituents bonded to the quaternary nitrogen atom, and each is independently a hydrogen atom or an organic group having 1 to 20 carbon atoms. R in Equation (1) 1 ~R 4 are preferably each independently an alkyl group having 1 to 20 carbon atoms or a hydroxyalkyl group having 1 to 20 carbon atoms. R 1 ~R 4 Among these, at least two are preferably alkyl groups having 1 to 20 carbon atoms, more preferably at least two are alkyl groups having 1 to 4 carbon atoms, and preferably at least two are alkyl groups having 1 carbon atom (methyl groups). That is, the ammonium carboxylate having a specific structure in the present invention preferably has at least two methyl groups bonded to the quaternary nitrogen atom.

[0014] In formula (1), from the viewpoint of suppressing a decrease in the expansion ratio of the polyurethane foam, R 1 ~R 4 All of the groups are methyl groups, or R 1 ~R 4 It is more preferable that two of the substituents are methyl groups and the remaining substituent is a hydroxyalkyl group having 1 to 20 carbon atoms. The hydroxyalkyl group having 1 to 20 carbon atoms is preferably a hydroxyalkyl group having 1 to 15 carbon atoms, more preferably a hydroxyalkyl group having 1 to 10 carbon atoms, and even more preferably a hydroxyalkyl group having 2 to 5 carbon atoms. Preferred hydroxyalkyl groups are hydroxyethyl groups such as a 2-hydroxyethyl group, and hydroxypropyl groups such as a 2-hydroxypropyl group.

[0015] The quaternary ammonium cation in formula (1) preferably has the structure of formula (1-1) or (1-2) below, from the viewpoint of suppressing a decrease in the expansion ratio when forming a polyurethane foam. [ka]

[0016] X in formula (1) - is a carboxylate anion having two or less carbon atoms. Here, the carboxylate anion having two or less carbon atoms is specifically a formate anion (HCOO - ) or acetate anion (CH3COO - ), and from the viewpoint of effectively suppressing the decrease in the expansion ratio, acetate anion (CHCOO - )

[0017] From the viewpoint of suppressing a decrease in the foaming ratio, the content of the ammonium carboxylate having a specific structure is preferably 1 to 30 parts by mass, more preferably 2 to 25 parts by mass, and even more preferably 3 to 15 parts by mass, relative to 100 parts by mass of the polyol. The ammonium carboxylate having a specific structure may be used alone or in combination of two or more.

[0018] The trimerization catalyst may contain a trimerization catalyst other than the ammonium carboxylate salt of the specific structure (hereinafter also referred to as "other trimerization catalyst"). Examples of other trimerization catalysts include metal catalysts and ammonium salts other than the ammonium carboxylate salt of the specific structure. Other metal catalysts (trimerization metal catalysts) used as trimerization catalysts include potassium organic acids, preferably potassium octylate such as potassium 2-ethylhexanoate, potassium acetate, potassium propionate, potassium butanoate, potassium benzoate, and other potassium carboxylates having 2 to 8 carbon atoms. Examples of ammonium salts other than the ammonium carboxylate salts having specific structures include ammonium carboxylate salts in which the carboxylic acid contains 3 or more carbon atoms. Specific examples of the carboxylic acid include 2-ethylhexanoic acid and 2,2-dimethylpropanoic acid.

[0019] The other trimerization catalyst preferably contains a metal catalyst, more preferably contains a potassium carboxylate having 2 to 8 carbon atoms, and even more preferably contains a potassium octoate such as potassium 2-ethylhexanoate. By using a carboxylic acid ammonium salt having a specific structure in combination with potassium octylate, it becomes easier to suppress a decrease in the foaming ratio. The other trimerization catalyst may not be used. That is, the content of the other trimerization catalyst relative to the total amount of catalyst may be 0% by mass. When the ammonium carboxylate salt of the specific structure and the other trimerization catalyst are used in combination, the content of the other trimerization catalyst is, for example, 10 to 100 parts by mass, preferably 20 to 80 parts by mass, relative to 100 parts by mass of the ammonium carboxylate salt of the specific structure.

[0020] (resinification catalyst) The catalyst may contain a resinification catalyst. The resinification catalyst preferably contains a heterocyclic compound having a nitrogen atom (hereinafter also referred to as a "nitrogen-containing heterocyclic compound"). When the resinification catalyst contains a nitrogen-containing heterocyclic compound and also contains the above-described ammonium carboxylate of the specific structure as a trimerization catalyst, it becomes easier to suppress a decrease in the expansion ratio when forming a polyurethane foam. Among the nitrogen-containing heterocyclic compounds, it is more preferable to contain an imidazole derivative. The imidazole derivative is less susceptible to the influence of the hydrofluoroolefin described below, and facilitates the reaction between the polyol and the polyisocyanate while increasing the stability of the polyol composition. Therefore, by including the imidazole derivative in the polyol composition, the reactivity between the polyol and the polyisocyanate is increased, and the foaming property is further improved. The imidazole derivative is preferably an imidazole substituted at the 1st and 2nd positions with an alkyl group having 8 or less carbon atoms, and the alkyl group preferably has 6 or less carbon atoms, more preferably 4 or less carbon atoms. A preferred specific example of the imidazole derivative is represented by the following general formula (2).

[0021] [ka] (In general formula (2), R 5 and R 6 each independently represents an alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms.

[0022] R in general formula (2) 5 and R 6 each independently represents an alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms. The alkyl group and the alkenyl group may each be linear or have a branched structure. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a hexyl group, a heptyl group, and an octyl group. Specific examples of the alkenyl group include a vinyl group, a 1-propenyl group, an allyl group, an isopropenyl group, a 1-butenyl group, a 2-butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, and an octenyl group. R 5 and R 6 When the number of carbon atoms in the alkyl group or alkenyl group in R is equal to or greater than the lower limit, steric hindrance increases, making the polymer less susceptible to the influence of blowing agents such as hydrofluoroolefins, which is preferable. 5 and R 6 When the number of carbon atoms in the alkyl group is equal to or less than the upper limit, the steric hindrance is not extremely large, so that the reaction between the polyol and the polyisocyanate can proceed quickly, and the foaming property is also good. From these perspectives, R 5 and R 6 are each independently preferably an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and further preferably a methyl group.

[0023] Examples of the imidazole derivative represented by general formula (2) include 1,2-dimethylimidazole, 1-ethyl-2-methylimidazole, 1-methyl-2-ethylimidazole, 1,2-diethylimidazole, and 1-isobutyl-2-methylimidazole. Among them, 1,2-dimethylimidazole and 1-isobutyl-2-methylimidazole are preferred from the viewpoint of improving the activity of the catalyst in the presence of hydrofluoroolefin and promoting the reaction rapidly. Furthermore, 1,2-dimethylimidazole is even more preferred from the viewpoint of further enhancing stability.

[0024] The content of the nitrogen-containing heterocyclic compound in the polyol composition is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 1 to 5 parts by mass, relative to 100 parts by mass of the polyol. When the content of the nitrogen-containing heterocyclic compound is equal to or greater than the lower limit, urethane bond formation is facilitated, the reaction proceeds rapidly, and foaming properties are improved. On the other hand, when the content of the nitrogen-containing heterocyclic compound is equal to or less than the upper limit, the reaction rate can be easily controlled, which is preferable.

[0025] The resinification catalyst may contain a metal catalyst. This metal catalyst is generally called a resinification metal catalyst. In the present invention, when the resinification metal catalyst is contained and the ammonium carboxylate having the specific structure described above is also contained as a trimerization catalyst, a decrease in the foaming ratio during formation of a polyurethane foam is more easily suppressed. Furthermore, by incorporating a resinified metal catalyst, it becomes easier to appropriately control the reaction rate between the polyol and the polyisocyanate. The resinified metal catalyst is preferably a bismuth compound containing bismuth or a tin compound containing tin, and more preferably a bismuth compound.

[0026] The resinified metal catalyst is preferably a metal salt selected from bismuth and tin, more preferably a bismuth salt. The metal salt is preferably an organic acid metal salt, more preferably a metal salt of a carboxylic acid having 5 or more carbon atoms. When the carboxylic acid has 5 or more carbon atoms, stability to blowing agents, particularly hydrofluoroolefins, is improved. Furthermore, from the viewpoint of catalytic activity, the number of carbon atoms in the carboxylic acid is preferably 18 or less, more preferably 12 or less. The carboxylic acid is preferably an aliphatic carboxylic acid, more preferably a saturated aliphatic carboxylic acid. The carboxylic acid may be linear or may have a branched structure, but preferably has a branched structure. Specific examples of carboxylic acids include octylic acid, lauric acid, versatic acid, pentanoic acid, and acetic acid, among which octylic acid is preferred. That is, the transition metal salt is preferably a metal salt of octylic acid. These carboxylic acids may be linear as described above, but may also have a branched structure. An example of an octylic acid having a branched structure is 2-ethylhexanoic acid. The metal salt of a carboxylic acid may be an alkyl metal carboxylate. For example, the tin carboxylate may be a dialkyltin carboxylate, preferably a dioctyltin carboxylate. Specific examples of metal salts of carboxylic acids include bismuth trioctate, dioctyltin versatate, dibutyltin dilaurate, dioctyltin dilaurate, and tin dioctylate, with bismuth trioctate and dioctyltin versatate being preferred, and bismuth trioctate being more preferred. As the organic acid metal salt described above, from the viewpoint of easily suppressing foaming after curing when combined with a hydroxyl group-containing ammonium carboxylate, an organic acid bismuth salt is preferred, a bismuth salt of a carboxylic acid is more preferred, and a bismuth salt of octylic acid is even more preferred.

[0027] The content of the resinified metal catalyst in the polyol composition is not particularly limited, but is preferably 0.1 to 5 parts by mass, more preferably 0.2 to 3 parts by mass, and even more preferably 0.3 to 1 part by mass, per 100 parts by mass of the polyol.

[0028] The total content of the resinification catalyst in the polyol composition is not particularly limited, but is preferably 0.2 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 1 to 5 parts by mass, per 100 parts by mass of the polyol compound.

[0029] <Polyol> Examples of polyols contained in the polyol composition of the present invention include polylactone polyols, polycarbonate polyols, polyester polyols, polymer polyols, and polyether polyols.

[0030] Examples of polylactone polyols include polypropiolactone glycol, polycaprolactone glycol, and polyvalerolactone glycol. Examples of polycarbonate polyols include polyols obtained by dealcoholization reaction of hydroxyl group-containing compounds such as ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, octanediol, and nonanediol with ethylene carbonate, propylene carbonate, and the like.

[0031] Examples of polyester polyols include polymers obtained by dehydration condensation of polybasic acids and polyhydric alcohols, and condensates of hydroxycarboxylic acids and the above-mentioned 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.

[0032] Examples of polymer polyols include polymers obtained by graft polymerizing an ethylenically unsaturated compound such as acrylonitrile, styrene, methyl acrylate, or methacrylate with an aromatic polyol, alicyclic polyol, aliphatic polyol, or polyester polyol, polybutadiene polyol, or hydrogenated products thereof.

[0033] Examples of polyether polyols include polymers obtained by ring-opening polymerization of an alkylene oxide having 2 to 6 carbon atoms, specifically at least one of ethylene oxide, propylene oxide, tetrahydrofuran, etc., in the presence of at least one low-molecular-weight active hydrogen compound having two or more active hydrogens, such as a polyhydric alcohol. Examples of the alkylene oxide include at least one of ethylene oxide and propylene oxide. Examples of low molecular weight active hydrogen compounds having two or more active hydrogens include diols such as bisphenol A, ethylene glycol, propylene glycol, butylene glycol, and 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 derivatives thereof; phloroglucinol; and cresol. polyols such as pyrogallol, catechol, hydroquinone, bisphenol A, bisphenol F, bisphenol S, 1,3,6,8-tetrahydroxynaphthalene, and 1,4,5,8-tetrahydroxyanthracene; polyfunctional (e.g., having 2 to 100 functional groups) polyols such as castor oil polyol, (co)polymers of hydroxyalkyl (meth)acrylate, and polyvinyl alcohol; condensates of phenol and formaldehyde (novolac), amines such as ethylenediamine, and butylenediamine.

[0034] The polyol used in the present invention is preferably a polyester polyol or a polyether polyol. Furthermore, a polyol having two hydroxyl groups is preferred. Among these, from the viewpoint of enhancing the flame retardancy of the polyurethane foam, an aromatic polyester polyol, which is a polyester polyol having an aromatic ring, is preferred. In this case, the weighted average aromatic concentration of the polyol is preferably 3% by mass or more, more preferably 5% by mass or more. The upper limit of the weighted average aromatic concentration of the polyol is not particularly limited, but is, for example, 30% by mass, preferably 25% by mass. Here, the aromatic concentration is obtained by the mass % of the total of carbon atoms and hydrogen atoms constituting the aromatic rings in the polyol, and the weighted average aromatic concentration is the aromatic concentration calculated by taking a weighted average of the respective contents of carbon atoms and hydrogen atoms in the aromatic rings. 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. Among these, from the viewpoint of improving the flame retardancy, particularly the flame spread resistance, of the polyurethane foam, the aromatic polyester polyol more preferably contains a phthalic acid-based polyester polyol which is a condensate of phthalic acid and a glycol, and even more preferably contains at least one selected from p-phthalic acid-based polyester polyol which is a condensate of p-phthalic acid and a glycol, and o-phthalic acid-based polyester polyol which is a condensate of o-phthalic acid and a glycol.

[0035] When the polyol contains an aromatic polyester polyol, the content thereof is not particularly limited, but is preferably 50 parts by mass or more, more preferably 70 parts by mass or more, and even more preferably 100 parts by mass, per 100 parts by mass of the polyol.

[0036] The weighted average hydroxyl value of the polyol is preferably 20 to 370 mgKOH / g, more preferably 50 to 320 mgKOH / g, and even more preferably 100 to 260 mgKOH / g. When the hydroxyl value of the polyol is equal to or less than the upper limit, the viscosity of the polyol composition tends to decrease, which is preferable from the viewpoint of handleability, etc. On the other hand, when the hydroxyl value of the polyol is equal to or more than the lower limit, the crosslink density of the polyurethane foam increases, thereby increasing the strength and improving the workability when sprayed. The hydroxyl value of the polyol can be measured in accordance with JIS K 1557-1:2007.

[0037] Here, the weighted average hydroxyl value of a polyol is calculated by multiplying the hydroxyl values ​​of the individual polyols constituting the polyol by the weight fraction of each polyol in the polyol. For example, when two types of polyol (d1) and polyol (d2) are used as the polyols, the weighted average hydroxyl value is expressed by the following formula, where X1 is the hydroxyl value of polyol (d1), m1 is the blending amount, and X2 is the hydroxyl value of polyol (d2), m2 is the blending amount. The blending amounts m1 and m2 are the parts by mass per 100 parts by mass of polyol. Weighted average hydroxyl value (mgKOH / g)=X1×(m1 / (m1+m2))+X2×(m2 / (m1+m2))

[0038] <Foaming agent> Specific examples of blowing agents include water, low-boiling hydrocarbons, chlorinated aliphatic hydrocarbon compounds, fluorine compounds, hydrochlorofluorocarbon compounds, hydrofluorocarbons, ether compounds, hydrofluoroolefins, etc. Further 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 point hydrocarbon include propane, butane, pentane, hexane, heptane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, and cycloheptane. Examples of the chlorinated aliphatic hydrocarbon compounds include dichloroethane, propyl chloride, isopropyl chloride, butyl chloride, isobutyl chloride, pentyl chloride, and isopentyl chloride. Examples of the fluorine compound include CHF3, CH2F2, and CH3F. Examples of the hydrochlorofluorocarbon compounds include trichloromonofluoromethane, trichlorotrifluoroethane, dichloromonofluoroethane (e.g., HCFC141b (1,1-dichloro-1-fluoroethane), HCFC22 (chlorodifluoromethane), and HCFC142b (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 compounds include diisopropyl ether. Examples of the hydrofluoroolefin 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-hexafluorobut-2-ene), and HFO-1224yd(Z).

[0039] Among the above, hydrofluoroolefins, water, and the like are preferred as the blowing agent, and it is more preferred to use hydrofluoroolefins and water in combination. In general, when a blowing agent containing a hydrofluoroolefin is used as described above, the expansion ratio of the polyurethane foam formed tends to decrease due to deactivation of the catalyst. However, in the present invention, even when a hydrofluoroolefin is used, the decrease in the expansion ratio can be suppressed. From the viewpoint of adjusting the density of the foam within a desired range, the content of the blowing agent is preferably 20 to 85 parts by mass, more preferably 30 to 70 parts by mass, and even more preferably 35 to 55 parts by mass, per 100 parts by mass of the polyol.

[0040] The amount of hydrofluoroolefin used as a blowing agent is preferably 20 to 70 parts by mass, more preferably 30 to 60 parts by mass, and even more preferably 33 to 50 parts by mass, per 100 parts by mass of polyol, from the viewpoint of achieving a polyurethane foam density within a desired range.

[0041] As the water used as a blowing agent, for example, ion-exchanged water, distilled water, etc. can be used appropriately. The amount of water per 100 parts by mass of polyol is preferably 0.1 to 15 parts by mass, more preferably 0.2 to 10 parts by mass, and even more preferably 0.3 to 5 parts by mass. By setting the water content within the above range, a good balance between flame retardancy and foaming properties can be achieved.

[0042] <Flame retardant> The polyol composition of the present invention contains a flame retardant. The flame retardant preferably contains a phosphorus-based compound, from the viewpoint of easily imparting excellent flame retardancy to the polyurethane foam. Examples of the phosphorus-based compound include compounds having a phosphorus atom, such as red phosphorus-based flame retardants, phosphate esters, phosphate salts, phosphazene compounds, and metal phosphinates.

[0043] (Red phosphorus flame retardant) The polyol composition of the present invention contains a red phosphorus-based flame retardant. The red phosphorus-based flame retardant may be red phosphorus alone, red phosphorus coated with a resin, metal hydroxide, metal oxide, or the like, or a mixture of red phosphorus with a resin, metal hydroxide, metal oxide, or the like. The resin used to coat or mix with the 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 to be used may be appropriately selected from those described below.

[0044] (phosphate ester) Examples of phosphate esters that can be used include monophosphate esters and condensed phosphate esters. Phosphate esters that are liquid at room temperature (25°C) and normal pressure (1 atm) are preferably used. A monophosphate ester is a phosphate ester having one phosphorus atom in the 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, cresyl diphenyl phosphate, and diphenyl(2-ethylhexyl)phosphate; and acidic phosphate esters such as monoisodecyl phosphate and diisodecyl phosphate.

[0045] Examples of the condensed phosphate ester include aromatic condensed phosphate esters such as trialkyl polyphosphate, resorcinol polyphenyl phosphate, bisphenol A polycresyl phosphate, and bisphenol A polyphenyl phosphate. Commercially available condensed phosphate esters include, for example, "CR-733S," "CR-741," and "CR747" manufactured by Daihachi Chemical Industry Co., Ltd., and "ADEKA STAB PFR" and "FP-600" manufactured by ADEKA Corporation.

[0046] The phosphate ester-based flame retardants may be used singly or in combination of two or more of the above-mentioned ones. Among them, from the viewpoint of easily adjusting the viscosity of the polyol composition to an appropriate level and improving the flame retardancy of the polyurethane foam, monophosphate esters are preferred, and halogen-containing phosphate esters such as tris(β-chloropropyl)phosphate are more preferred.

[0047] (phosphate) Specific examples of phosphates include monophosphates, polyphosphates, intumescent compounds, etc. The term "phosphate" as used herein includes not only orthophosphates but also phosphites, hypophosphites, etc. The same applies to polyphosphates. Examples of monophosphates 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; zinc salts such as zinc phosphate, zinc phosphite, and zinc hypophosphite; and aluminum salts such as aluminum monophosphate, aluminum diphosphate, aluminum triphosphate, aluminum phosphite, and aluminum hypophosphite. Examples of polyphosphates include ammonium polyphosphate, piperazine polyphosphate, melamine polyphosphate, ammonium amide polyphosphate, and aluminum polyphosphate.

[0048] Examples of intumescent compounds include phosphates containing a phosphorus-based component that promotes carbonization and a nitrogen-based component that promotes fire extinguishing and foaming. When combustion begins and heating occurs, intumescent compounds produce bubbles on the surface of the material, creating a foamy, adiabatic expansion layer that prevents heat from the surface of the material from being transferred to the interior, and also inhibits thermal decomposition and oxidation reactions by blocking the supply of oxygen, thereby fulfilling the role of a flame retardant.

[0049] Examples of phosphorus-based components constituting intumescent compounds include polyphosphoric acids such as pyrophosphoric acid and triphosphoric acid, and monophosphoric acids such as orthophosphoric acid (normal phosphoric acid).

[0050] Examples of nitrogen-based components constituting the intumescent compounds include aliphatic diamines such as N,N,N',N'-tetramethyldiaminomethane, ethylenediamine, N,N'-dimethylethylenediamine, N,N'-diethylethylenediamine, N,N-dimethylethylenediamine, N,N-diethylethylenediamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetraethylethylenediamine, 1,2-propanediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, and 1,10-diaminodecane; piperazine; trans-2,5-dimethylpiperazine; 1,4-bis(2-aminoethyl)piperazine; 1, Examples thereof include amine compounds containing a piperazine ring such as 4-bis(3-aminopropyl)piperazine, and amine compounds containing a triazine ring such as melamine, acetoguanamine, benzoguanamine, acrylguanamine, 2,4-diamino-6-nonyl-1,3,5-triazine, 2,4-diamino-6-hydroxy-1,3,5-triazine, 2-amino-4,6-dihydroxy-1,3,5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4-diamino-6-ethoxy-1,3,5-triazine, 2,4-diamino-6-propoxy-1,3,5-triazine, 2,4-diamino-6-isopropoxy-1,3,5-triazine, 2,4-diamino-6-mercapto-1,3,5-triazine, and 2-amino-4,6-dimercapto-1,3,5-triazine.

[0051] (Phosphazene compounds) A phosphazene compound is an organic compound in which phosphorus atoms and nitrogen atoms are alternately bonded. Examples of the phosphazene compound include cyclic phosphazene compounds, chain phosphazene compounds, and crosslinked phosphazene compounds crosslinked by a crosslinking group. Specific examples of the phosphazene compound include those containing a structural unit represented by the following general formula (3):

[0052] [ka] In the general formula (3), each X independently represents an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 12 carbon atoms, an amino group, or a halogen atom. In the general formula (3), examples of the substituent on the aryl group include an alkyl group, an amino group, and a halogen atom. Each X is preferably independently any one of a phenyl group, a substituted phenyl group, a phenyloxy group, and a substituted phenyl group, and more preferably any one of a phenyl group and a phenyloxy group.

[0053] (metal phosphinate) The metal phosphinate is a metal salt of an organic phosphinic acid. Specific examples of the metal phosphinate include aluminum trisdiethylphosphinate, aluminum trismethylethylphosphinate, aluminum trisdiphenylphosphinate, zinc bisdiethylphosphinate, zinc bismethylethylphosphinate, zinc bisdiphenylphosphinate, titanyl bisdiethylphosphinate, titanium tetrakisdiethylphosphinate, titanyl bismethylethylphosphinate, titanium tetrakismethylethylphosphinate, titanyl bisdiphenylphosphinate, and titanium tetrakisdiphenylphosphinate.

[0054] The content of the phosphorus-based compound in the polyol composition of the present invention is preferably 30 to 200 parts by mass, more preferably 45 to 150 parts by mass, and even more preferably 60 to 120 parts by mass, per 100 parts by mass of the polyol. When the content of the phosphorus-based compound is equal to or greater than the above-mentioned lower limit, good flame retardancy can be imparted to the polyurethane foam. On the other hand, when the content of the phosphorus-based compound is equal to or less than the above-mentioned upper limit, flame retardancy commensurate with the content of the phosphorus-based compound can be imparted. The phosphorus-based compounds may be used alone or in combination of two or more.

[0055] Of the above-mentioned phosphorus-based compounds contained as a flame retardant in the polyol composition of the present invention, at least one selected from red phosphorus-based flame retardants and phosphoric acid esters is preferred.

[0056] The content of the red phosphorus-based flame retardant in the polyol composition of the present invention is preferably 10 to 70 parts by mass, more preferably 15 to 50 parts by mass, and even more preferably 20 to 45 parts by mass, per 100 parts by mass of the polyol. When the content of the red phosphorus-based flame retardant is equal to or greater than the above-mentioned lower limit, good flame retardancy can be imparted to the polyurethane foam. On the other hand, when the content of the red phosphorus-based flame retardant is equal to or less than the above-mentioned upper limit, flame retardancy commensurate with the content of the red phosphorus-based flame retardant can be imparted.

[0057] The content of the phosphate ester-based flame retardant in the polyol composition is not particularly limited, but is preferably 20 to 150 parts by mass, more preferably 30 to 120 parts by mass, and even more preferably 40 to 100 parts by mass, per 100 parts by mass of the polyol. When the content of the phosphate ester-based flame retardant is equal to or greater than these lower limits, flame retardancy can be easily imparted to the polyurethane foam without excessively increasing the viscosity of the polyol composition. On the other hand, when the content of the phosphate ester-based flame retardant is equal to or less than these upper limits, foaming is not inhibited, and polyurethane foam can be easily produced.

[0058] The flame retardant may contain a flame retardant other than the above-mentioned phosphorus-based compounds. Examples of the flame retardant other than the phosphorus-based compounds include bromine-containing flame retardants, boron-containing flame retardants, antimony-containing flame retardants, and metal hydroxides. These flame retardants may be used alone or in combination of two or more.

[0059] <Foam stabilizer> The polyol composition of the present invention may contain a foam stabilizer. As the foam stabilizer, a compound having a polar portion and a non-polar portion in the molecule and having a surfactant effect can be suitably used. The foam stabilizer is not particularly limited, but examples thereof include surfactants such as polyoxyalkylene foam stabilizers (e.g., polyoxyalkylene alkyl ethers) and silicone foam stabilizers (e.g., organopolysiloxanes). Silicone foam stabilizers may also be graft copolymers of polyoxyalkylene glycols, which are polymers of ethylene oxide or propylene oxide, with polydimethylsiloxane. Commercially available products may also be used, including SH-193 (manufactured by Dow Corning Toray Co., Ltd.), S-824-02 (Nippon Unicar Co., Ltd.), SZ-1704 (Nippon Unicar Co., Ltd.), F501 (Shin-Etsu Chemical Co., Ltd.), and SF-2937F (manufactured by Dow Toray Co., Ltd.). The content of the foam stabilizer is preferably 0.1 to 15 parts by mass, more preferably 0.5 to 12 parts by mass, and even more preferably 1 to 8 parts by mass, relative to 100 parts by mass of the polyol.

[0060] <Other ingredients> The foamable urethane resin composition may contain one or more additives selected from phenolic, amine, sulfuric, and other antioxidants, heat stabilizers, light stabilizers, metal inhibitors, antistatic agents, stabilizers, crosslinking agents, lubricants, softeners, pigments, dyes, fillers, and the like, as needed, provided the object of the present invention is not impaired.

[0061] <Manufacturing method> There are no particular limitations on the method for producing the polyol composition of the present invention, and it can be produced, for example, by stirring the components at about room temperature using a mixer such as a homodisper for about 30 seconds to 20 minutes.

[0062] [Polyurethane resin composition, polyurethane foam] The foamable urethane resin composition of the present invention contains the above-mentioned polyol composition and a polyisocyanate. More specifically, the foamable urethane resin composition is obtained by mixing at least the above-mentioned polyol composition and a polyisocyanate.

[0063] <Polyisocyanate> The polyisocyanate contained in the foamable urethane resin composition of the present invention can be any of various polyisocyanate compounds, such as aromatic, alicyclic, and aliphatic polyisocyanates, having two or more isocyanate groups. Liquid diphenylmethane diisocyanate (MDI) is preferred because of its ease of handling, rapid reaction, excellent physical properties of the resulting polyurethane foam, and low cost. Examples of liquid MDI include polymeric MDI. Specific commercial liquid MDI products include "44V-10" and "44V-20" (manufactured by Sumika Covestro Urethane Co., Ltd.), "Millionate MR-200" (manufactured by Nippon Polyurethane Industry Co., Ltd.), and "PM200" (manufactured by Wanka Chemical Japan Co., Ltd.). Uretonimine-containing MDI (e.g., commercially available product "Millionate MTL" manufactured by Nippon Polyurethane Industry Co., Ltd.) may also be used. Alternatively, a polyisocyanate compound may be used in which some of the isocyanate active groups have been reacted with a hydroxyl group-containing compound to enhance its affinity with polyols. In addition to liquid MDI, other polyisocyanates may be used in combination, and any polyisocyanate known in the technical field of polyurethanes may be used without limitation.

[0064] The isocyanate index of the foamable urethane resin composition of the present invention is preferably 200 or more, more preferably 230 or more, even more preferably 250 or more, and even more preferably 260 or more, from the viewpoints of properly forming a polyurethane foam and imparting good flame retardancy. The isocyanate index of the foamable urethane resin composition is preferably not more than 650, more preferably not more than 550, even more preferably not more than 520, and still more preferably not more than 500. When the isocyanate index is not more than these upper limit values, flame retardancy that is sufficiently commensurate with the production cost can be obtained. The isocyanate index (INDEX) is calculated by the following method.

[0065] INDEX = number of equivalents of polyisocyanate ÷ (number of equivalents of polyol + number of equivalents of water) × 100 where: Polyisocyanate equivalents = number of parts of polyisocyanate used x NCO content (%) x 100 / NCO molecular weight Polyol equivalents = OHV x number of parts of polyol used ÷ molecular weight of KOH, where OHV is the hydroxyl value of the polyol (mgKOH / g). Equivalents of water = parts of water used x number of OH groups in water / molecular weight of water In the above formula, the unit 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 convenience of unit conversion in the above formula, the molecular weight of KOH is set to 56,100, the molecular weight of water is set to 18, and the number of OH groups in water is set to 2.

[0066] <Ratio of foaming completion time to curing time> The ratio of the foaming completion time to the curing time of the foamable urethane resin composition of the present invention is preferably 3 or more. When this ratio is 3 or more, a decrease in the expansion ratio of the formed polyurethane foam is easily suppressed. From this viewpoint, the ratio of the foaming completion time to the curing time of the foamable urethane resin composition is preferably 3.5 or more, more preferably 4 or more, and preferably 10 or less.

[0067] The curing time is the time from when the reaction between the polyol composition and the polyisocyanate compound starts (0 seconds) to when curing is completed (time until no uncured material remains). The time at which the reaction between the polyol composition and the polyisocyanate compound starts is, for example, the time at which stirring is started when mixing the polyol composition and the polyisocyanate compound. The time until curing is completed is the time until no uncured material adheres to the foam when pressed with a finger or the like during foaming.

[0068] The foaming completion time is the time from when the reaction between the polyol composition and the polyisocyanate compound starts (measurement start time (0 seconds)) until foaming is completed. The time when the reaction started is as described above. The time until foaming is completed is the time when the height change of the formed foam becomes 1 mm / 5 seconds or less.

[0069] [Method for manufacturing polyurethane foam] Although there are no particular limitations on the method for producing the polyurethane foam, it is preferable to produce the polyurethane foam by mixing the polyol composition with the polyisocyanate in a foaming machine or the like and reacting and foaming the resulting mixed liquid (foamable urethane resin composition). The polyurethane foam is preferably formed by spray foaming the foamable urethane resin composition, and specifically, it is preferable to use a spray device having a spray gun or the like. The polyol composition is preferably fed to a foaming machine and mixed by collision inside the foaming machine with a polyisocyanate fed from another container, etc. The mixed liquid (foamable urethane resin composition) is then discharged from a discharge port of a spray gun, etc., and a polyurethane foam is formed from the discharged foamable urethane resin composition.

[0070] [Application] The uses of the foamable urethane resin composition of the present invention and the polyurethane foam formed from the composition are not particularly limited, and they can be used for filling cavities in structures such as buildings, furniture, automobiles, trains, ships, etc., or for spraying onto such structures. Among these, use for spraying onto structures, i.e., spraying applications, is preferred, and use for spraying at building construction sites is more preferred. Spraying can be carried out using a spraying device (e.g., A-25 manufactured by GRACO) and a spray gun (e.g., D-gun manufactured by Gasmar). Spraying can be carried out by adjusting the temperature of the polyol composition and polyisocyanate contained in separate containers in the spraying device, causing them to collide and mix at the tip of the spray gun, and then 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. Furthermore, the temperature settings and pressure of the raw liquid can be set according to general spraying conditions for polyurethane foam. [Example]

[0071] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The components used in the examples and comparative examples are shown below.

[0072] <Polyol> Aromatic polyester polyol: p-phthalic acid-based polyester polyol (Kawasaki Chemical Industries, Ltd., product name: Maximol RLK-087, aromatic concentration 8%, hydroxyl value = 200 mg KOH / g)

[0073] <Polyisocyanate> 4,4'-Diphenylmethane diisocyanate (4,4'-MDI) (Manka Chemical Japan Co., Ltd., product name: PM200)

[0074] <Foam stabilizer> Silicone foam stabilizer (Toray Dow Corning SH-193)

[0075] <Flame retardant> Phosphate ester flame retardant: Tris(β-chloropropyl)phosphate (manufactured by Daihachi Chemical Co., Ltd., product name: TMCPP) Red phosphorus flame retardant (Rinkagaku Kogyo Co., Ltd., product name: NovaExcel 140)

[0076] <Foaming agent> ·water HFO-1233zd (hydrofluoroolefin) (Honeywell, product name: Solstice LBA)

[0077] <Catalyst> Trimerization catalyst: Triethylmethylammonium 2-ethylhexanoate, San-Apro Co., Ltd. "U-cat 18X", concentration approximately 100% by mass Trimerization catalyst: N-(2-hydroxyethyl)-N-(2-hydroxypropyl)-N,N-dimethylammonium acetate, Kao Corporation "Kao Raiser No. 410", concentration 100% by mass Trimerization catalyst: tetramethylammonium acetate, Tosoh "Toyocat-TRX", concentration 65% by mass Trimerization catalyst: 2-ethylhexanoic acid potassium salt, "DABCO K-15" manufactured by Air Products, Inc., concentration 70-80% by mass Resinification catalyst: bismuth trioctate, "Neostan U-600" manufactured by Nitto Kasei Co., Ltd., concentration 55-58% by mass Resinification catalyst: 1,2-dimethylimidazole, Tosoh Corporation "TOYOCAT-DM70", concentration 65-75% by mass

[0078] [Example 1] Polyol compositions and polyisocyanate compounds having the formulations shown in Table 1 were prepared and subjected to the following evaluations.

[0079] <Curing time> The liquid temperatures of the polyol composition and polyisocyanate compound listed in Table 1 were each adjusted to 10°C. Next, in a room at 23°C, the polyol composition adjusted to 10°C was poured into a 500 mL cup (Teraoka's "Descup 500 mL"). The polyisocyanate compound was then poured into the cup so that the total amount of the mixed solution was 80 g, at a mixing ratio that would result in an isocyanate index as shown in Table 1. The mixed solution was then immediately stirred at 8000 rpm for 2 seconds using a Lab-Iso Disper (PRIMIX Corporation's high-speed disperser, Homo Disper 2.5). The time when stirring began was designated the measurement start time (0 seconds). The foam was pressed with a finger during foaming, and the time until no uncured material adhered to the foam was measured, and this was designated the curing time.

[0080] <Foaming completion time> The liquid temperatures of the polyol composition and polyisocyanate compound listed in Table 1 were each adjusted to 10°C. Next, in a room at 23°C, the polyol composition adjusted to 10°C was poured into a 500 mL cup (Teraoka's "Descup 500 mL"). The polyisocyanate compound was then poured into the cup so that the total amount of the mixed solution was 80 g, at a mixing ratio that would result in an isocyanate index as shown in Table 1. The mixed solution was then immediately stirred at 8000 rpm for 2 seconds using a Labo Body Spa (PRIMIX Corporation's high-speed disperser, Homo Disper 2.5). The time when stirring began was defined as the measurement start time (0 seconds). The time (elapsed time from the measurement start time) when the height change of the formed foam became 1 mm / 5 seconds or less was defined as the foaming completion time.

[0081] <Form height (without curing)> In measuring the foaming completion time, when the height of the foamed product stopped changing, the height from the bottom of the cup to the top (highest point) of the foamed product was measured, and this was taken as the foam height (without curing).

[0082] <Foam height after curing at 55°C for 3 days> A polyol composition having the formulation shown in Table 1 was aged for 3 days at 55°C. Using the polyol composition aged in this manner, the foam height was measured in the same manner as above, and this was designated as the "foam height after aging at 55°C for 3 days." Note that when aging is performed as described above, the catalyst in the polyol composition is generally deactivated by the hydrofluoroolefin. Then, the foam height change rate after curing at 55°C for 3 days was calculated based on the following formula. Foam height change rate (%) after curing at 55°C for 3 days = 100 x (foam height (without curing) - foam height after curing at 55°C for 3 days) / foam height (without curing) Furthermore, if the foam height change rate after curing at 55°C for 3 days is small, it means that the foam expansion ratio of the polyurethane foam can be maintained and the density can be reduced even if the catalyst is deactivated. (judgement) ○: The foam height change rate after curing at 55℃ for 3 days is less than 10% ×: The foam height change rate after curing at 55°C for 3 days is more than 10%

[0083] [Examples 2 to 7, Comparative Examples 1 and 2] Each evaluation was carried out in the same manner as in Example 1, except that the formulation was changed as shown in Table 1.

[0084] [Table 1]

[0085] The polyol compositions in each example contain a polyol, a catalyst, a blowing agent, and a flame retardant, and also contain, as a trimerization catalyst, an ammonium carboxylate salt in which the carboxylic acid contains two or less carbon atoms. When polyurethane foams were produced using the polyol compositions, the foam height change rate after curing at 55°C for 3 days was low, and it was found that the polyurethane foams could maintain a high expansion ratio even when stored for a long period of time in the presence of a hydrofluoroolefin. In contrast, the polyol composition of Comparative Example 1 did not contain an ammonium carboxylate salt, and curing failure occurred during the production of polyurethane foam. The polyol composition of Comparative Example 2 contained an ammonium carboxylate salt, but the ammonium carboxylate salt did not contain a carboxylic acid having two or fewer carbon atoms, and therefore the foam height change rate after curing at 55°C for 3 days was high, and the expansion ratio was found to be low.

Claims

1. A polyol composition for reacting with a polyisocyanate compound to obtain a polyurethane foam, comprising: the polyol composition comprises a polyol, a catalyst, a blowing agent, and a flame retardant; the catalyst comprises an ammonium carboxylate salt; The polyol composition, wherein the carboxylic acid of the ammonium carboxylate contains 2 or less carbon atoms.

2. 2. The polyol composition of claim 1, wherein the ammonium carboxylate has at least two methyl groups attached to a quaternary nitrogen atom.

3. The polyol composition according to claim 1 or 2, wherein the catalyst comprises an organic acid bismuth salt.

4. The polyol composition according to claim 1 or 2, wherein the catalyst comprises a heterocyclic compound having a nitrogen atom.

5. The polyol composition according to claim 1 or 2, wherein the flame retardant comprises a phosphorus-based compound.

6. A foamable urethane resin composition obtained by mixing the polyol composition according to claim 1 or 2 with a polyisocyanate.

7. 7. The foamable urethane resin composition according to claim 6, wherein the ratio of the foaming completion time to the curing time is 3 or more.

8. 7. The foamable urethane resin composition according to claim 6, having an isocyanate index of 250 or more.

9. A polyurethane foam formed by spray foaming the foamable urethane resin composition according to claim 6.

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