JP7545203B2 - Polyol composition, foamable polyurethane composition, and polyurethane foam - Google Patents

Description

The present invention relates to a polyol composition, a foamable polyurethane composition containing the polyol composition, and a polyurethane foam formed from the foamable polyurethane composition.

Due to its excellent insulating and adhesive properties, polyurethane foam is used as an insulating material for buildings such as apartment complexes, detached houses, various school facilities, and commercial buildings. Polyurethane foam is obtained by mixing a polyol composition and a polyisocyanate at the construction site of a building, foaming the mixture, and spraying the mixture onto objects such as ceilings, walls, and roofs using a spray device.

Polyol compositions generally contain catalysts such as resinification catalysts and trimerization catalysts. Resinification catalysts promote the reaction between polyol compounds and polyisocyanates, while trimerization catalysts promote the production of polyisocyanurates by reacting polyisocyanates with each other, thereby increasing the proportion of polyisocyanurates. Nitrogen-containing aromatic compounds, alkali metal carboxylates, ammonium salts, etc. are used as trimerization catalysts, and amine catalysts, etc. are known to be used as resinification catalysts (see, for example, Patent Document 1).

JP 2018-80328 A

Conventional polyol compositions containing the above-mentioned catalysts are required to have good foaming properties from the viewpoint of ease of handling. On the other hand, when the polyol composition is stored before being used, for example, at a construction site of a building, the catalyst may react with the blowing agent in the polyol composition, causing a decrease in foaming properties, and it is therefore desirable to improve storage stability. In particular, hydrofluoroolefins (HFOs), which have a low global warming potential, have been widely used as blowing agents in recent years, but HFOs tend to react easily with catalysts, making them more susceptible to a decrease in storage stability.

Therefore, the objective of the present invention is to provide a polyol composition that has excellent foaming properties and storage stability.

As a result of intensive research, the present inventors have found that the above-mentioned problems can be solved by a polyol composition containing a polyol compound, a blowing agent, and a catalyst, and the catalyst contains a guanidine derivative, an imidazole derivative, and an alkali metal salt, and have completed the present invention. That is, the present invention provides the following [1] to [11].
[1] A polyol composition comprising a polyol compound, a blowing agent and a catalyst, the catalyst comprising a guanidine derivative, an imidazole derivative and an alkali metal salt.
[2] The polyol composition according to claim 1, wherein the guanidine derivative is a tetraalkylguanidine, the imidazole derivative is a di-substituted imidazole derivative, and the alkali metal salt is an alkali metal carboxylate.
[3] The polyol composition according to claim 1 or 2, wherein the alkali metal salt is a potassium salt.
[4] The polyol composition according to any one of claims 1 to 3, wherein the guanidine derivative is 1,1,3,3-tetramethylguanidine, the imidazole derivative is an imidazole derivative substituted with an alkyl group having 1 to 5 carbon atoms, and the alkali metal salt is a carboxylate having 6 to 10 carbon atoms.
[5] The polyol composition according to any one of claims 1 to 4, wherein the imidazole derivative comprises 1,2-dimethylimidazole, and the alkali metal salt comprises potassium 2-ethylhexanoate.
[6] The polyol composition according to any one of claims 1 to 5, comprising 0.5 to 30 parts by mass of the guanidine derivative, 0.5 to 30 parts by mass of the imidazole derivative, and 5 to 60 parts by mass of the alkali metal salt relative to 100 parts by mass of the polyol compound.
[7] The polyol composition according to any one of claims 1 to 6, wherein the blowing agent comprises a hydrofluoroolefin.
[8] The polyol composition according to any one of claims 1 to 7, comprising a filler, the content of the filler being 10 parts by mass or more relative to 100 parts by mass of the polyol compound.
[9] A foamable polyurethane composition comprising the polyol composition according to any one of claims 1 to 8 and a polyisocyanate.
[10] The foamable polyurethane composition according to claim 9, having an isocyanate index of 250 or more.
[11] A polyurethane foam obtained by reacting and foaming the foamable polyurethane composition according to claim 9 or 10.

The present invention provides a polyol composition with excellent foaming properties and storage stability.

[Polyol composition]
The polyol composition of the present invention comprises a polyol compound, a blowing agent, and a catalyst. Each component in the polyol composition of the present invention will be described in detail below.

[Polyol compound]
The polyol composition of the present invention contains a polyol compound that is a raw material for polyurethane foam. Examples of the polyol compound include polylactone polyol, polycarbonate polyol, aromatic polyol, alicyclic polyol, aliphatic polyol, polyester polyol, polymer polyol, and polyether polyol. The polyol compound is usually liquid at room temperature (23° C.) and normal pressure (1 atm).

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.

Examples of aromatic polyols include bisphenol A, bisphenol F, phenol novolac, and cresol novolac.
Examples of alicyclic polyols include cyclohexanediol, methylcyclohexanediol, isophoronediol, dicyclohexylmethanediol, and dimethyldicyclohexylmethanediol.
Aliphatic polyols include, for example, alkanediols such as ethylene glycol, propylene glycol, butanediol, pentanediol, and hexanediol.

Examples of polyester polyols include polymers obtained by dehydration condensation of polybasic acids and polyhydric alcohols, polymers obtained by ring-opening polymerization of lactones such as ε-caprolactone and α-methyl-ε-caprolactone, 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), and succinic acid, etc. 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, etc.
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-polymerizing ethylenically unsaturated compounds such as acrylonitrile, styrene, and methacrylate with aromatic polyols, alicyclic polyols, aliphatic polyols, and polyester polyols, polybutadiene polyols, and modified polyols of polyhydric alcohols, or hydrogenated products thereof.

Examples of modified polyols of polyhydric alcohols include those obtained by reacting a raw material polyhydric alcohol with an alkylene oxide to modify it.
Examples of polyhydric alcohols include trihydric alcohols such as glycerin and trimethylolpropane, and polyfunctional polyols (e.g., having 2 to 100 functional groups) such as pentaerythritol, sorbitol, mannitol, sorbitan, diglycerin, glucose, (co)polymers of hydroxyalkyl (meth)acrylates, and polyvinyl alcohol.

Although the method for modifying the polyhydric alcohol is not particularly limited, a method of adding an alkylene oxide (hereinafter also referred to as "AO") is preferably used. Examples of the AO include AOs having 2 to 6 carbon atoms, such as ethylene oxide (hereinafter also referred to as "EO"), 1,2-propylene oxide (hereinafter also referred to as "PO"), 1,3-propylene oxide, 1,2-butylene oxide, and 1,4-butylene oxide.
Among these, from the viewpoints of properties and reactivity, PO, EO and 1,2-butylene oxide are preferred, and PO and EO are more preferred. When two or more AOs are used (for example, PO and EO), the addition method may be block addition or random addition, or a combination of these may be used.

Examples of polyether polyols include polymers obtained by ring-opening polymerization of at least one alkylene oxide, such as ethylene oxide, propylene oxide, and tetrahydrofuran, in the presence of at least one low-molecular-weight active hydrogen compound having two or more active hydrogens. 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, and amines such as ethylenediamine and butylenediamine.

The polyol compound used in the present invention is not particularly limited, but polyester polyols are preferred from the viewpoint of foaming properties and reactivity. Among them, aromatic polyester polyols obtained by dehydration condensation of a polybasic acid having an aromatic ring, such as isophthalic acid (m-phthalic acid), and a dihydric alcohol, such as bisphenol A, are more preferred. The use of aromatic polyester polyols makes it easier to improve flame retardancy.

The hydroxyl value of the polyol is preferably 20 to 350 mgKOH/g, more preferably 50 to 300 mgKOH/g, and even more preferably 100 to 250 mgKOH/g. If 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 ease of handling. On the other hand, if 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. The hydroxyl value of the polyol can be measured according to JIS K 1557-1:2007.

[catalyst]
The polyol composition of the present invention contains a guanidine derivative, an imidazole derivative, and an alkali metal salt as a catalyst. By containing these compounds, the polyol composition of the present invention has excellent foaming properties and storage stability.

<Guanidine derivatives>
The guanidine derivative used in the present invention is a compound having a guanidine skeleton, and a specific example thereof is tetraalkylguanidine, which is a 1,1,3,3-tetraalkylguanidine in which a total of four hydrogen atoms bonded to the nitrogen atoms at positions 1 and 3 are each independently substituted with an alkyl group.
Specific examples of tetraalkylguanidine include compounds represented by the following general formula (1). In the present invention, by using a guanidine derivative in addition to an imidazole derivative and an alkali metal salt, the reaction between polyol and isocyanate can be started and progressed early, and the cream time can be shortened and the gel time can be set to an appropriate speed. As described below, even if the isocyanate index is increased or a trimerization catalyst with high catalytic activity is used, the trimerization catalyst and the urethane reaction occur in a well-balanced manner, unreacted polyol is less likely to remain, and the foaming property is also good. Therefore, for example, dripping when spraying at the construction site of a building can be prevented. In addition, the activation of the above reaction makes it easier to generate reaction heat, and such reaction heat promotes not only the urethane reaction but also the trimerization reaction of polyisocyanate without using an excessive amount of a trimerization catalyst (alkali metal salt), thereby improving the flame retardancy of the polyurethane foam. In addition, since the tetraalkylguanidine is not taken into the polyurethane foam and volatilizes, it can be prevented from causing odors after construction.

(In formula (1), R ¹ , R ² , R ³ and R ⁴ each independently represent an alkyl group.)

The alkyl group of R ¹ , R ² , R ³ , and R ⁴ is, for example, an alkyl group having 1 to 16 carbon atoms, and preferably has 1 to 4 carbon atoms. The alkyl group may be linear, branched, or have a cyclic 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 cyclopentyl group, a hexyl group, a cyclohexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, etc. Among these, from the viewpoints of stability and foaming property, a methyl group is preferred, and 1,1,3,3-tetramethylguanidine in which the above four alkyl groups are all methyl groups is more preferred.

The content of the guanidine derivative is preferably 0.5 to 30 parts by mass, more preferably 2 to 25 parts by mass, and even more preferably 5 to 18 parts by mass, per 100 parts by mass of the polyol compound. By setting the content of the guanidine derivative at or above the lower limit, the reaction proceeds sufficiently immediately after mixing, reaction heat is generated, and the trimerization reaction and the urethanization reaction occur in a well-balanced manner, further improving the foamability. In addition, as described below, even if a relatively large amount of filler is blended, the foamability is maintained well. On the other hand, by setting the content at or below the upper limit, an effect commensurate with the content can be obtained, and the urethanization reaction can be prevented from proceeding excessively.

<Imidazole derivatives>
The imidazole derivative used in the polyol composition of the present invention is a compound having an imidazole skeleton, and a disubstituted imidazole derivative is preferred. The imidazole derivative is preferably an imidazole compound substituted with an alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms, and more preferably an imidazole derivative substituted with an alkyl group having 1 to 5 carbon atoms. The imidazole derivative is less susceptible to the influence of hydrofluoroolefin, and makes it easier to react the polyol compound with the polyisocyanate while increasing the stability of the polyol composition. A specific example of the imidazole derivative is represented by the following general formula (2).

(In formula (2), ^R5 and ^R6 each independently represent an alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms.)

In the general formula (2), ^R5 and ^R6 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 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.
When the carbon numbers of the alkyl or alkenyl groups of ^R5 and ^R6 are within the above range, the reaction between the polyol compound and the polyisocyanate can be rapidly promoted while minimizing the influence of the blowing agent such as hydrofluoroolefin due to moderate steric hindrance. From these viewpoints, ^R5 and ^R6 are each independently preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and further preferably a methyl group.
Specific 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 these, 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 from the viewpoint of rapidly progressing the reaction. Furthermore, 1,2-dimethylimidazole is more preferred from the viewpoint of further increasing stability.

The content of the imidazole derivative in the polyol composition is preferably 0.5 to 30 parts by mass, more preferably 2.0 to 20 parts by mass, and even more preferably 4.5 to 12 parts by mass, per 100 parts by mass of the polyol compound. If the content of the imidazole derivative is equal to or greater than the lower limit, urethane bonds are more likely to be formed, and the reaction proceeds quickly. Furthermore, as described below, even if a relatively large amount of filler is blended, the reaction proceeds quickly and good foamability is maintained. On the other hand, if the content of the imidazole derivative is equal to or less than the upper limit, the reaction rate is easier to control, which is preferable.

<Alkali metal salt>
The catalyst in the polyol composition of the present invention contains an alkali metal salt in addition to the guanidine derivative and the imidazole derivative. By containing the alkali metal salt, when the polyol composition is mixed with a polyisocyanate, not only foaming is promoted but also the trimerization of the polyisocyanate is promoted, thereby improving the flame retardancy of the polyurethane foam.

As the alkali metal salt, from the viewpoint of foaming property, an alkali metal carboxylate is preferred. Examples of the alkali metal carboxylate include lithium salt, sodium salt, potassium salt, rubidium salt, cesium salt, and francium salt, and among these, potassium salt is preferred.

Examples of the carboxylic acid used in the alkali metal salt include saturated aliphatic carboxylic acids, unsaturated aliphatic carboxylic acids, hydroxy acids, aromatic carboxylic acids, dicarboxylic acids, tricarboxylic acids, oxocarboxylic acids, etc. The number of carbon atoms in the carboxylic acid is preferably 1 to 20, more preferably 3 to 15, and even more preferably 6 to 10. The carboxylic acid may be either linear or branched, but is preferably branched.
The saturated aliphatic carboxylic acid is a monocarboxylic acid, and examples thereof include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, 2-ethylhexanoic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, margaric acid, and stearic acid.
Examples of unsaturated aliphatic carboxylic acids include oleic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, and sorbic acid.
Hydroxy acids include, for example, lactic acid, malic acid, and citric acid.
Examples of aromatic carboxylic acids include benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, mellitic acid, and cinnamic acid.
Examples of dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, and maleic acid.
An example of the tricarboxylic acid is aconitic acid.
Examples of oxocarboxylic acids include pyruvic acid and oxaloacetic acid.
As the carboxylic acid of the alkali metal salt used in the present invention, from the viewpoints of stability, flame retardancy, etc., a saturated aliphatic carboxylic acid is preferred, and a saturated aliphatic carboxylic acid having 6 to 10 carbon atoms is more preferred.
Specific preferred examples of the alkali metal salt include potassium 2-ethylhexanoate and potassium acetate, with potassium 2-ethylhexanoate being particularly preferred.

The content of the potassium carboxylate is preferably 5 to 60 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 compound. By setting the content to be equal to or greater than the lower limit, the trimerization of the polyisocyanate is sufficiently promoted, making it easier to obtain good flame retardancy. Furthermore, as described below, even if a relatively large amount of filler is blended, the trimerization proceeds sufficiently. On the other hand, by setting the content to be equal to or less than the upper limit, the trimerization of the polyisocyanate is prevented from proceeding excessively, and unreacted polyol is prevented from remaining, resulting in good mechanical properties of the polyurethane foam.

[Foaming agent]
The polyol composition of the present invention preferably contains a hydrofluoroolefin as a blowing agent from the viewpoint of environmental protection and foaming property. In the present invention, even when a hydrofluoroolefin is used as a blowing agent, the storage stability is high and the catalytic activity is not easily decreased. Examples of the hydrofluoroolefin include fluoroalkenes having about 3 to 6 carbon atoms. The hydrofluoroolefin may be a hydrochlorofluoroolefin having a chlorine atom, and therefore may be a chlorofluoroalkene having about 3 to 6 carbon atoms.
More specific examples include trifluoropropene, tetrafluoropropenes such as HFO-1234, pentafluoropropenes such as HFO-1225, chlorotrifluoropropenes such as HFO-1233, chlorodifluoropropene, chlorotrifluoropropene, and chlorotetrafluoropropene. More specific examples include 1,3,3,3-tetrafluoropropene (HFO-1234ze), 1,1,1,2,3-pentafluoropropene (HFO-1225yez), 1-chloro-3,3,3-trifluoropropene (HFO-1233zd), and 1,1,1,4,4,4-hexafluorobut-2-ene. Of these, HFO-1233zd is preferred.
These hydrofluoroolefins may be used alone or in combination of two or more kinds.

The content of the hydrofluoroolefin is preferably 20 to 70 parts by mass, more preferably 25 to 60 parts by mass, and even more preferably 30 to 50 parts by mass, per 100 parts by mass of the polyol compound. When the content of the hydrofluoroolefin is equal to or greater than the lower limit, foaming is promoted and the density of the resulting polyurethane foam can be reduced. On the other hand, when the content of the hydrofluoroolefin is equal to or less than the upper limit, excessive foaming can be suppressed.

The polyol composition of the present invention may contain a blowing agent other than hydrofluoroolefin.The blowing agent other than hydrofluoroolefin may include, for example, water, organic physical blowing agent, inorganic physical blowing agent, etc.The organic physical blowing agent may include low boiling point hydrocarbons such as propane, butane, dimethyl ether, and cyclopropane, chlorinated aliphatic hydrocarbon compounds such as dichloroethane and propyl chloride, and ether compounds such as diisopropyl ether.The inorganic physical blowing agent may include oxygen gas, argon gas, and carbon dioxide gas.
Of the above compounds, water is preferred from the viewpoints of adjusting the isocyanate index and ease of handling.

The content of water in the polyol composition is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.5 to 3 parts by mass, per 100 parts by mass of the polyol compound. When the content of the blowing agent is equal to or greater than the lower limit, foaming is promoted, and the density of the resulting polyurethane foam can be reduced. On the other hand, when the content of the blowing agent is equal to or less than the upper limit, excessive foaming can be suppressed.

[Filler]
The polyol composition of the present invention preferably contains a filler. In the present invention, by including a filler, various physical properties such as flame retardancy and mechanical properties of the resulting polyurethane foam can be easily improved. In addition, in the present invention, even if a filler is included, the reaction between the polyol and the isocyanate can be initiated and progressed early by using the above-mentioned combination of catalysts.
The filler is usually in a state of being dispersed in the polyol composition as a powder component and constitutes at least a part of the solid content (insoluble content). The filler is a component that becomes solid at room temperature (23° C.) and normal pressure (1 atm).
Specific examples of the filler include solid flame retardants. Specific examples of the solid flame retardants include red phosphorus-based flame retardants, phosphate-containing flame retardants, bromine-containing flame retardants, chlorine-containing flame retardants, antimony-containing flame retardants, boron-containing flame retardants, needle-shaped fillers, and metal hydroxides. These may be used alone or in combination of two or more.

<Red phosphorus-based flame retardants>
The red phosphorus-based flame retardant may be made of red phosphorus alone, may be red phosphorus coated with a resin, a metal hydroxide, a metal oxide, or may be red phosphorus mixed with a resin, a metal hydroxide, a metal oxide, or the like. The resin that coats the red phosphorus or mixes with the red phosphorus is not particularly limited, but examples thereof include thermosetting resins such as phenol resin, epoxy resin, unsaturated polyester resin, melamine resin, urea resin, aniline resin, and silicone resin. From the viewpoint of flame retardancy, metal hydroxides are preferred as the compound to be coated or mixed. The metal hydroxide to be used may be appropriately selected from those described below.

The content of the red phosphorus-based flame retardant in the polyol composition is preferably 5 to 40 parts by mass, more preferably 12 to 35 parts by mass, even more preferably 15 to 32 parts by mass, and even more preferably 20 to 28 parts by mass, per 100 parts by mass of the polyol compound. By making the content of the red phosphorus-based flame retardant equal to or greater than these lower limits, the effect of including the red phosphorus-based flame retardant is easily exhibited. On the other hand, by making the content equal to or less than the upper limits, foaming is not inhibited by the red phosphorus-based flame retardant.

<Phosphate-containing flame retardants>
Specific examples of phosphate-containing flame retardants include phosphates formed from salts of various phosphoric acids and at least one metal or compound selected from the group consisting of metals in Groups IA to IVB of the periodic table, ammonia, aliphatic amines, aromatic amines, and heterocyclic compounds containing nitrogen in the ring.
The phosphoric acid is not particularly limited, but examples thereof include monophosphoric acid, pyrophosphoric acid, and polyphosphoric acid.
Examples of metals in 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, piperazine, etc. Examples of aromatic amines include aniline, o-triidine, 2,4,6-trimethylaniline, anisidine, 3-(trifluoromethyl)aniline, etc. Examples of heterocyclic compounds containing nitrogen in the ring include pyridine, triazine, melamine, etc.

Specific examples of the phosphate-containing flame retardant include monophosphate, pyrophosphate, polyphosphate, etc. Here, the polyphosphate is not particularly limited, but examples thereof include ammonium polyphosphate, piperazine polyphosphate, melamine polyphosphate, ammonium amide polyphosphate, aluminum polyphosphate, etc.
The phosphate-containing flame retardant may be used alone or in combination of two or more of the above-mentioned compounds.

The content of the phosphate-containing flame retardant in the polyol composition is not particularly limited, but 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 the polyol compound. By making the content of the phosphate-containing flame retardant equal to or greater than these lower limits, the effect of including the phosphate-containing flame retardant is easily exhibited. On the other hand, by making the content equal to or less than the upper limits, foaming is not inhibited by the phosphate-containing flame retardant.

<Bromine-containing flame retardants>
The bromine-containing flame retardant is not particularly limited as long as it contains bromine in its molecular structure and is a solid at room temperature and pressure. Examples of the bromine-containing flame retardant include brominated aromatic ring-containing aromatic compounds.
Examples of the brominated aromatic ring-containing aromatic compound include monomeric organic bromine compounds such as hexabromobenzene, pentabromotoluene, hexabromobiphenyl, decabromobiphenyl, decabromodiphenyl ether, bis(pentabromophenoxy)ethane, ethylene bis(pentabromophenyl), and ethylene bis(tetrabromophthalimide).

In addition, the brominated aromatic ring-containing aromatic compound may be a bromine compound polymer.Specific examples thereof include brominated polycarbonates such as polycarbonate oligomers produced from brominated bisphenol A as a raw material, copolymers of the polycarbonate oligomers and bisphenol A, and diepoxy compounds produced by the reaction of brominated bisphenol A and epichlorohydrin.Furthermore, examples thereof include brominated epoxy compounds such as monoepoxy compounds obtained by the reaction of brominated phenols and epichlorohydrin, brominated phenol condensates of brominated polyphenylene ether, brominated bisphenol A and cyanuric chloride, and brominated polystyrenes such as uncrosslinked or crosslinked brominated polystyrene.
In addition, compounds other than brominated aromatic ring-containing aromatic compounds such as hexabromocyclododecane may be used.
These bromine-containing flame retardants may be used alone or in combination of two or more.
Among the above, brominated aromatic ring-containing aromatic compounds are preferred, and among these, monomeric organic bromine compounds such as ethylenebis(pentabromophenyl) are preferred.

The content of the bromine-containing flame retardant in the polyol composition is preferably 3 to 45 parts by mass, more preferably 14 to 40 parts by mass, even more preferably 18 to 38 parts by mass, and even more preferably 23 to 32 parts by mass, per 100 parts by mass of the polyol compound. By making the content of the bromine-containing flame retardant equal to or greater than these lower limits, the effect of including the bromine-containing flame retardant is easily exerted. On the other hand, by making the content equal to or less than the upper limits, foaming is not inhibited by the bromine-containing flame retardant.

<Chlorine-containing flame retardants>
Chlorine-containing flame retardants include those commonly used in polyurethane foams, such as polychlorinated naphthalenes, chlorendic acid, and dodecachlorododecahydrodimethanodibenzocyclooctene, sold under the trade name "Dechlorane Plus."
The content of the chlorine-containing flame retardant in the polyol composition is not particularly limited, but 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, relative to 100 parts by mass of the polyol compound. By making the content of the chlorine-containing flame retardant equal to or greater than these lower limits, the effect of containing the chlorine-containing flame retardant is easily exhibited. On the other hand, by making the content equal to or less than the upper limits, foaming is not inhibited by the chlorine-containing flame retardant.

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

The content of the antimony-containing flame retardant in the polyol composition is not particularly limited, but is preferably 1 to 40 parts by mass, more preferably 2 to 35 parts by mass, and even more preferably 3 to 30 parts by mass, per 100 parts by mass of the polyol compound. By making the amount of the antimony-containing flame retardant equal to or greater than these lower limits, the effect of the inclusion of the antimony-containing flame retardant is more easily exerted, and flame retardancy is improved. On the other hand, by making the amount equal to or less than the upper limits, foaming is not inhibited by the antimony-containing flame retardant.

<Boron-containing flame retardants>
Examples of boron-containing flame retardants include borax, boron oxide, boric acid, borates, etc. Examples of boron oxide include diboron trioxide, boron trioxide, diboron dioxide, tetraboron trioxide, and tetraboron pentoxide.
Examples of borates include borates of alkali metals, alkaline earth metals, elements of Groups 4, 12, and 13 of the periodic table, and ammonium. Specific examples 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.
The boron-containing flame retardants may be used alone or in combination of two or more.
The boron-containing flame retardant used in the present invention is preferably a borate, more preferably zinc borate.

The content of the boron-containing flame retardant in the polyol composition is not particularly limited, but is preferably 1 to 40 parts by mass, more preferably 3 to 20 parts by mass, even more preferably 5 to 15 parts by mass, and even more preferably 7 to 13 parts by mass, per 100 parts by mass of the polyol compound. By making the content of the boron-containing flame retardant equal to or greater than these lower limits, the effect of the inclusion of the boron-containing flame retardant is more easily exerted, and flame retardancy is improved. On the other hand, by making the content equal to or less than the upper limits, foaming is not inhibited by the boron-containing flame retardant.

<Needle filler>
Examples of the needle-like filler include potassium titanate whiskers, aluminum borate whiskers, silicon-containing whiskers, wollastonite, sepiolite, zonolite, elestadite, boehmite, asbestos fibers, carbon fibers, graphite fibers, slag fibers, silica fibers, alumina fibers, zirconia fibers, boron nitride fibers, stainless steel fibers, etc. The aspect ratio (length/diameter) of the needle-like filler is preferably in the range of 5 to 50, and more preferably in the range of 10 to 40.

The content of the needle-shaped filler in the polyol composition is not particularly limited, but is preferably 20 to 90 parts by mass, more preferably 30 to 85 parts by mass, and even more preferably 45 to 75 parts by mass, per 100 parts by mass of the polyol compound. By making the content of the needle-shaped filler equal to or greater than these lower limits, the effect of including the needle-shaped filler is more easily exerted, and flame retardancy is improved. On the other hand, by making the content equal to or less than the upper limits, foaming is not inhibited by the needle-shaped filler.

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

The content of the metal hydroxide in the polyol composition is preferably 0.2 to 30 parts by mass, more preferably 0.3 to 20 parts by mass, and even more preferably 0.5 to 15 parts by mass, per 100 parts by mass of the polyol compound. By making the content of the metal hydroxide equal to or greater than these lower limits, the effect of including the metal hydroxide is more easily exhibited, and flame retardancy is improved. On the other hand, by making the content equal to or less than the upper limits, foaming is not inhibited by the metal hydroxide.

As the filler, inorganic fillers other than the above-mentioned solid flame retardants may be used. Examples of such inorganic fillers include alumina, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, ferrites, basic magnesium carbonate, calcium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, dawsonite, hydrotalcite, calcium sulfate, barium sulfate, gypsum fiber, calcium silicate, talc, clay, mica, montmorillonite, bentonite, activated clay, seviolite, imogolite, sericite, glass beads, silica balloon, aluminum nitride, boron nitride, silicon nitride, graphite, carbon balloon, charcoal powder, various metal powders, potassium titanate, magnesium sulfate, lead zirconate titanate, molybdenum sulfide, silicon carbide, various magnetic powders, and fly ash.

The content of the filler in the polyol composition is preferably 10 parts by mass or more relative to 100 parts by mass of the polyol compound. In the present invention, by making the content of the filler equal to or more than the above lower limit, it becomes easier to impart various functions such as flame retardancy to the polyurethane foam. From these viewpoints, the content of the filler in the polyol composition is more preferably 30 parts by mass or more, even more preferably 40 parts by mass or more, and even more preferably 50 parts by mass or more relative to 100 parts by mass of the polyol compound.
The content of the filler in the polyol composition is preferably 120 parts by mass or less, more preferably 100 parts by mass or less, and even more preferably 90 parts by mass or less, relative to 100 parts by mass of the polyol compound. By setting the content of the filler to the above upper limit or less, the content of the catalyst can be appropriately adjusted to maintain good foamability.

As the filler, it is preferable to use the above-mentioned solid flame retardant. By using the solid flame retardant, the flame retardancy of the obtained polyurethane foam is further improved. Among the above-mentioned solid flame retardants, at least one selected from bromine-containing flame retardants, boron-containing flame retardants, and needle-shaped fillers is preferable from the viewpoints of flame retardancy, foamability, handling, etc.
As the filler, a solid flame retardant may be used alone, or a solid flame retardant may be used in combination with a filler other than the solid flame retardant. The content of the solid flame retardant relative to the total amount of the filler is, for example, 50 to 100 mass%, preferably 70 to 100 mass%, more preferably 90 to 100 mass%.

[Liquid flame retardant]
The polyol composition may contain a liquid flame retardant as a flame retardant. The liquid flame retardant is preferably used in combination with a solid flame retardant. The liquid flame retardant is a flame retardant that is liquid at room temperature and normal pressure. A specific example of the liquid flame retardant is a phosphoric acid ester. By including a liquid flame retardant in the polyol composition, the flame retardancy of the polyol composition is easily improved, and by using a solid flame retardant and a liquid flame retardant in combination, the flame retardancy is further easily improved.

As the phosphate ester, for example, monophosphate ester, condensed phosphate ester, etc. can be used. A monophosphate ester is a phosphate ester that has one phosphorus atom in the molecule. There are no particular limitations on the phosphate ester as long as it is liquid at room temperature and normal pressure, but specific examples include trialkyl phosphates such as trimethyl phosphate, halogen-containing phosphate esters such as tris(β-chloropropyl)phosphate, trialkoxyphosphates such as tributoxyethyl phosphate, and aromatic ring-containing phosphate esters such as tricresyl phosphate.

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.

The liquid flame retardants may be used alone or in combination of two or more of the above. Among these, monophosphate esters are preferred from the viewpoint of making it easier to adjust the viscosity of the polyol composition to an appropriate level and from the viewpoint of improving the flame retardancy of the polyurethane foam, and halogen-containing phosphate esters such as tris(β-chloropropyl)phosphate are more preferred.

When the polyol composition contains a liquid flame retardant, the content of the liquid flame retardant in the polyol composition is preferably 15 to 80 parts by mass, more preferably 20 to 70 parts by mass, and even more preferably 30 to 60 parts by mass, per 100 parts by mass of the polyol compound. By making the content of the liquid flame retardant equal to or greater than these lower limits, the effect of including the liquid flame retardant is easily exerted. Furthermore, by making the content equal to or less than the upper limits, the liquid flame retardant does not inhibit the foaming of the foamable polyurethane composition.

[Foam stabilizer]
The polyol composition of the present invention may contain a foam stabilizer. By containing a foam stabilizer, the foamability of the polyurethane foam can be improved, and for example, foaming can be promoted when reacting with a polyisocyanate during spraying.
The foam stabilizer may be specifically a surfactant, more specifically a polyoxyalkylene foam stabilizer such as polyoxyalkylene alkyl ether, or a silicone foam stabilizer such as organopolysiloxane. The foam stabilizer used in the present invention is not particularly limited, but from the viewpoint of foaming property, a silicone foam stabilizer is preferred. The foam stabilizer may be used alone or in combination of two or more kinds.

The content of the foam stabilizer in the polyol composition of the present invention is preferably 0.1 to 10 parts by mass, more preferably 1 to 8 parts by mass, and even more preferably 2 to 6 parts by mass, per 100 parts by mass of the polyol compound. If the content of the foam stabilizer is equal to or greater than the lower limit, foaming is facilitated when the polyol composition and the polyisocyanate are reacted, making it possible to obtain a homogeneous polyurethane foam. If the content of the foam stabilizer is equal to or less than the upper limit, an effect that is sufficiently commensurate with the production cost can be obtained.

[Other additives]
The polyol composition may contain additives other than those described above, provided that the purpose of the present invention is not impaired. Examples of such additives include phenol-based, amine-based, and sulfur-based antioxidants, heat stabilizers, metal inhibitors, antistatic agents, stabilizers, crosslinking agents, lubricants, softeners, and additives such as tackifier resins, and tackifiers such as polybutene and petroleum resins.

[Foamable Polyurethane Composition and Polyurethane Foam]
The foamable polyurethane composition of the present invention contains the polyol composition of the present invention and a polyisocyanate, and is obtained by mixing them. The polyurethane foam of the present invention is a reaction product obtained by reacting and foaming the foamable polyurethane composition.

[Polyisocyanate]
The polyisocyanate to be reacted with the polyol composition of the present invention may be any known polyisocyanate used in the formation of polyurethane foams. Examples of the polyisocyanate include aromatic polyisocyanates, alicyclic polyisocyanates, and aliphatic polyisocyanates.

Examples of aromatic polyisocyanates include phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, dimethyldiphenylmethane diisocyanate, triphenylmethane triisocyanate, naphthalene diisocyanate, and polymethylene polyphenyl polyisocyanate (polymeric MDI).

Examples of the alicyclic polyisocyanate include cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and dimethyldicyclohexylmethane diisocyanate.
Examples of the aliphatic polyisocyanate include methylene diisocyanate, ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, and hexamethylene diisocyanate.

Among these, from the viewpoints of ease of use and availability, aromatic polyisocyanates are preferred, and diphenylmethane diisocyanate, polymeric MDI, or a mixture thereof is more preferred. The polyisocyanates may be used alone or in combination of two or more types.

[Isocyanate Index]
The isocyanate index in the foamable polyurethane composition of the present invention is not particularly limited, but is preferably 250 or more. If the isocyanate index is equal to or more than the lower limit, the amount of polyisocyanate relative to the polyol becomes excessive, and isocyanurate bonds due to the trimer of polyisocyanate are easily formed, resulting in improved flame retardancy of the polyurethane foam. Furthermore, if the isocyanate index is equal to or more than the lower limit, it is easy to produce a polyurethane foam having sufficient isocyanurate bonds, that is, a polyurethane foam having both flame retardancy and heat insulation at a high level, in combination with the above-mentioned alkali metal salt, imidazole derivative, and guanidine derivative. From these viewpoints, the isocyanate index is more preferably 300 or more, more preferably 350 or more, and even more preferably 400 or more.
The isocyanate index is preferably not more than 1000, more preferably not more than 800, and even more preferably not more than 600. When the isocyanate index is not more than the upper limit, flame retardancy that is sufficiently commensurate with the production cost can be obtained.

The isocyanate index can be calculated by the following method.
Isocyanate index = equivalents of polyisocyanate ÷ (equivalents of polyol + equivalents of water) × 100
Here, each equivalent number can be calculated as follows:
Equivalent number of polyisocyanate = Amount of polyisocyanate used (g) × NCO content (mass%) / Molecular weight of NCO (mol) × 100
Equivalent number of polyol = OHV x amount of polyol used (g) ÷ molecular weight of KOH (mmol)
OHV is the hydroxyl value of the polyol (mg KOH/g).
Number of water equivalents = amount of water used (g) / molecular weight of water (mol) × number of OH groups in water In each of the above formulas, the molecular weight of NCO is 42 (mol), the molecular weight of KOH is 56,100 (mmole), the molecular weight of water is 18 (mol), and the number of OH groups in water is 2.

[Method of producing polyurethane foam]
The method for producing the polyurethane foam of the present invention is not particularly limited, but it is preferable to mix a polyisocyanate with a polyol composition to obtain a foamable polyurethane composition, and then foam and react the mixture. Specifically, it is preferable to mix the polyisocyanate with the polyol composition by collision using a spray device or the like, and then spray the mixture.
In the present invention, the polyurethane foam may be obtained by mixing the polyisocyanate and the polyol composition, pouring the mixture into a container such as a mold or a frame, and curing the mixture.

[Uses of polyurethane foam]
The uses of the polyurethane foam of the present invention are not particularly limited, but since it has excellent flame retardancy and heat insulation, it can be suitably used for the walls, ceilings, roofs, floors, etc. of buildings. It can also be suitably used as a member for filling any openings that occur in buildings, including joints and holes that occur between structural materials of buildings.

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

[Materials used]
<Polyisocyanate>
4,4'-Diphenylmethane diisocyanate (4,4'-MDI) (manufactured by Manka Chemical Japan Co., Ltd., product name: PM200)
<Polyol Compound>
p-Phthalic acid polyester polyol (manufactured by Kawasaki Chemical Industries, Ltd., product name: Maximol RLK-087, hydroxyl value = 200 mg KOH/g)
<Catalyst>
Guanidine derivative: 1,1,3,3-tetramethylguanidine (manufactured by Evonik Japan Co., Ltd., product name: POLYCAT 201, a mixture of water and ethylene glycol (1,1,3,3-tetramethylguanidine 60% by mass, ethylene glycol 32% by mass, water 8% by mass)
Imidazole derivatives (1)
1,2-Dimethylimidazole (manufactured by Tosoh Corporation, product name: TOYOCAT (registered trademark)-DM70, mixture with ethylene glycol (1,2-dimethylimidazole: 65 to 75% by mass, ethylene glycol: 25 to 35% by mass)
Imidazole derivatives (2)
1-Isobutyl-2-methylimidazole (manufactured by Evonik Japan Ltd., product name: NCIM, concentration: approximately 98% by mass)
Potassium carboxylate (1)
Potassium 2-ethylhexanoate (manufactured by Evonik Japan Ltd., product name: DABCO K-15, potassium 2-ethylhexanoate 70 to 80% by mass, diethylene glycol 20 to 30% by mass)
Potassium carboxylate (2)
Potassium acetate (manufactured by Evonik Japan Ltd., product name: POLYCAT 46, potassium acetate 38% by mass, ethylene glycol 62% by mass)
Comparative catalyst: N,N,N',N'',N''-pentamethyldiethylenetriamine (manufactured by Tosoh Corporation, product name: TOYOCAT (registered trademark)-TT)

<Foaming Agent>
Hydrofluoroolefin (manufactured by Honeywell Japan, product name: Solstice LBA, HFO-1233zd)
・Water (foam stabilizer)
Silicone foam stabilizer (Toray Dow Corning Co., Ltd., product name: SH-193)

<Liquid flame retardant>
Tris(β-chloropropyl)phosphate (manufactured by Daihachi Chemical Industry Co., Ltd., product name: TMCPP)
<Filler>
Wollastonite ( _SiO2.CaO ) (Kinsei Matec Co., Ltd., product name: SH-1250)

[Examples 1 to 9, Comparative Examples 1 to 5]
Each component was mixed according to the formulation shown in Table 1 to prepare a polyol composition, and the foaming property and storage stability were evaluated as described below. The polyol composition used in each evaluation was adjusted so that the polyol was 25 g.

[Foaming evaluation]
(Cream Time (CT), Gel Time (GT))
The polyol composition (25 g of polyol in the composition) prepared in each Example and Comparative Example was diluted with 150 g of TMCPP, and 75 g of isocyanate was further added and mixed, and the time from the completion of mixing to the start of the liquid level rising due to foaming was measured as the cream time. In addition, the time from the completion of mixing to the time when the resin becomes threaded around the metal rod or the hole pierced by the metal rod becomes closed when a metal rod is pierced into the foam during reaction was measured as the gel time.
As a result of the above measurements, a cream time (CT) of 1 to 10 seconds and a gel time (GT) of 10 to 70 seconds was evaluated as "good", and a cream time (CT) of 3 to 7 seconds and a gel time (GT) of 20 to 50 seconds was evaluated as "good". On the other hand, a case that did not meet the above criteria was evaluated as "poor".

[Storage stability evaluation]
The polyol compositions prepared in each of the Examples and Comparative Examples were stored in a thermostatic chamber at 60° C. for 7 days, and then the cream time (CT) and gel time (GT) were measured in the same manner as in the foaming property evaluation, and the compositions were evaluated according to the same evaluation criteria.

*The amount of each catalyst is the amount used in the product.

The polyurethane compositions of Examples 1 to 9 all had excellent foaming properties and storage stability. In contrast, the polyol compositions of Comparative Examples 1 to 3 had low foaming properties and storage stability. If any one of the guanidine derivative, the imidazole derivative, and the alkali metal salt was not contained, both the foaming properties and the storage stability were impaired.
The storage stability was not good for the polyol compositions of Comparative Examples 4 and 5. In the presence of an amine catalyst, the foaming property was good, but it is presumed that the decomposition of the hydrofluoroolefin was promoted by the amine catalyst during storage, and the storage stability was impaired.

Claims (10)

a polyol compound, a blowing agent, and a catalyst, the catalyst comprising a guanidine derivative, an imidazole derivative, and an alkali metal salt;
A polyol composition for spraying for forming a polyurethane foam used as a thermal insulating material for buildings, comprising 0.5 to 30 parts by mass of the guanidine derivative, 0.5 to 30 parts by mass of the imidazole derivative, and 5 to 60 parts by mass of the alkali metal salt relative to 100 parts by mass of the polyol compound (excluding those containing a tertiary amine catalyst having an isocyanate reactive group) . 2. The spray polyol composition of claim 1, wherein said guanidine derivative is a tetraalkylguanidine, said imidazole derivative is a disubstituted imidazole derivative, and said alkali metal salt is an alkali metal carboxylate. 3. The spray polyol composition of claim 1 or 2, wherein the alkali metal salt is a potassium salt. The polyol composition for spraying according to any one of claims 1 to 3, wherein the guanidine derivative is 1,1,3,3-tetramethylguanidine, the imidazole derivative is an imidazole derivative substituted with an alkyl group having 1 to 5 carbon atoms, and the alkali metal salt is a carboxylate having 6 to 10 carbon atoms. The spray polyol composition of any one of claims 1 to 4, wherein the imidazole derivative comprises 1,2-dimethylimidazole and the alkali metal salt comprises potassium 2-ethylhexanoate. The spray polyol composition of any one of claims 1 to 5, wherein the blowing agent comprises a hydrofluoroolefin. The polyol composition for spraying according to any one of claims 1 to 6, which contains a filler and the content of the filler is 10 parts by mass or more based on 100 parts by mass of the polyol compound. A foamable polyurethane composition for spray application , comprising the polyol composition for spray application according to any one of claims 1 to 7 and a polyisocyanate. 9. The foamable polyurethane composition for spray application according to claim 8, having an isocyanate index of 250 or more. 10. A polyurethane foam for spray application used as a thermal insulating material for buildings, which is obtained by reacting and foaming the foamable polyurethane composition for spray application according to claim 8 or 9.