Novel polyurethane foam catalysts with improved storage stability.

Abstract

The present invention relates to a polyol mixture comprising: a) 10% to 99.7% by weight of at least one polyol as component A; b) 0.1% to 30% by weight of a hydrohaloolefin blowing agent as component B; c) 0.1% to 10% by weight of water as component C; d) 0.1% to 10% by weight of a catalyst as component D; and e) optionally 0% to 80% by weight of one or more further additives as one or more further components E, wherein catalyst D comprises an imidazolium salt of general formula (I) [Formula (I)], wherein R1 and R2 are independently an aliphatic, alicyclic, araliphatic, or aromatic group having 1 to 20 carbon atoms, which group may further contain one or more heteroatoms, and A- represents a carboxylate anion having 1 to 20 carbon atoms, which anion may also contain one or more further heteroatoms. [Formula 1] TIFF2025526207000009.tif28170

Description

[Technical Field]

[0001] The present invention relates to polyol mixtures comprising a polyol, a hydrohaloolefin blowing agent, water, and an imidazolium salt catalyst, a process for making rigid polyurethane foams, and the use of imidazolium salts as catalysts. [Background technology]

[0002] Rigid polyurethane foams have been known for a long time and have been described in many different ways. They are primarily used for thermal insulation, for example in refrigeration equipment, transport or buildings, and also for the production of building elements, in particular sandwich elements.

[0003] It is important that the rigid polyurethane foam fills the cavity evenly and without gaps, forming a stable structure with the best possible connection to the outer layer, ensuring good insulation. To prevent foam failure, the foamable PU reaction mixture must be introduced into the cavity to be insulated within a short time. Low-pressure or, preferably, high-pressure machines are usually used to foam such objects.

[0004] A comprehensive review of the production of rigid polyurethane foams and their use as outer or core layers in composite elements, as well as their application as insulating layers in cooling or heating technology, is found, for example, in "Polyurethane" [Polyurethanes], Kunststoff-Handbuch [Plastics Handbook], volume 7, 3rd edition 1993, edited by Dr. Günter Oertel, Carl-Hanser-Verlag, Munich / Vienna.

[0005] Suitable rigid polyurethane foams can be prepared in known manner by reacting an organic polyisocyanate with one or more compounds containing at least two reactive hydrogen atoms in the presence of a blowing agent, a catalyst, and optionally auxiliaries and / or additives.

[0006] The compounds having at least two hydrogen atoms reactive with isocyanate groups used in the preparation of polyurethanes are preferably polyether alcohols and / or polyester alcohols. The choice of polyol is based, inter alia, on cost and the desired properties of use (see, for example, EP-A 1632511, U.S. Pat. No. B 6,495,722, WO 2006 / 108833).

[0007] Polyurethane foam compositions are typically produced by reacting an isocyanate with a premix containing an isocyanate-reactive component such as a polyol, preferably a polyether alcohol and / or a polyester alcohol. The premix optionally contains additional components such as water, a flame retardant, a blowing agent, a foam-stabilizing surfactant, and a catalyst, which promotes the reaction of the isocyanate with the polyol to form urethane, and the reaction of the isocyanate with water to form urea and release CO2. The blowing agent in the premix is usually a liquid with a sufficiently low boiling point that it vaporizes due to the heat generated during the polymerization reaction. Examples of blowing agents used in the production of insulating polyurethane foam include hydrofluorocarbons, hydrofluoroolefins, hydrofluorochloroolefins, hydrochlorofluorocarbons, formates, and hydrocarbons. In some applications, the premix is stored for up to one year before being converted into polyurethane foam using an isocyanate. This is common in spray foam applications, where drums of premix and isocyanate are supplied for on-site use. Therefore, it is desirable for the premix to be chemically and physically stable. However, catalysts suitable for accelerating the polyurethane reaction can undergo or induce undesired reactions with blowing agents present in the premix, thereby reducing the storage stability of the premix. Such undesired reactions occur when halogen-containing blowing agents are used, particularly unsaturated halogenated blowing agents. Typical amine catalysts suitable for producing polyurethane foams include tertiary amines, such as N,N,N',N'',N''-pentamethyldiethylenetriamine or 1,4-diazabicyclo[2.2.2]octane. The reaction of tertiary amines with halogen-containing organic compounds occurs more rapidly when the halogen atom is attached to an olefinic carbon, because halogen-substituted olefins are susceptible to nucleophilic attack by the tertiary amine, resulting in rapid deactivation of the tertiary amine catalyst.

[0008] EP 3091044 A1 discloses a polyol premix composition comprising a hydrohaloolefin blowing agent, at least one polyol, water, at least 10% by weight of tetramethylguanidine, and 10 to 90% by weight of a catalyst comprising one or more tertiary amines having an isocyanate-reactive group selected from 2-[N-(dimethylaminoethoxyethyl)-N-methylamino]ethanol and N,N,N'-trimethyl-N'-3-aminopropylbis(aminoethyl)ether.

[0009] European Patent Application Publication No. 2504372A1 states: (A) at least one polyisocyanate obtained by reacting at least one monomeric isocyanate; (B) at least one compound having at least two isocyanate-reactive groups, a number average molecular weight Mn of at least 1000 g / mol and an OH value of 40 to 350 mg KOH / g; (C) at least one imidazolium salt; (D) optionally a solvent; (E) optionally, a further urethanization catalyst different from (C); and (F) optionally further typical coating ingredients and / or additives; The present invention discloses a coating composition comprising: Summary of the Invention [Means for solving the problem]

[0010] It is an object of the present invention to provide a polyurethane blowing catalyst that is storage stable and does not deactivate in polyol mixtures containing hydrohaloolefin blowing agents.

[0011] The purpose of this is to a) at least one polyol as component A; b) a hydrohaloolefin blowing agent as component B; c) water as component C; d) a catalyst as component D; e) optionally one or more further additives as one or more further components E; Including, Catalyst D is an imidazolium salt of general formula (I) [ka] (wherein R1 and R2 are independently an aliphatic, alicyclic, araliphatic, or aromatic group having 1 to 20 carbon atoms, which may further contain one or more heteroatoms; A- is a carboxylate anion having 1 to 20 carbon atoms, which may further contain one or more additional heteroatoms.

[0012] The heteroatoms can be selected from oxygen, nitrogen, sulfur, and phosphorus. For example, R1, R2 can contain 1 to 5 heteroatoms, and A- can contain 1 to 5 additional heteroatoms.

[0013] The polyol mixture comprises at least one polyol as component A. In a preferred embodiment, the polyol component comprises a polyol typically used in the production of rigid PIR / PUR (polyisocyanurate and / or polyurethane) foams. Such polyols include, but are not limited to, polyalkylene ether and polyester polyols. In one embodiment, the polyalkylene ether includes poly(alkylene oxide) polymers, such as poly(ethylene oxide) polymers and poly(propylene oxide) polymers, and copolymers having terminal hydroxyl groups derived from polyhydric compounds including diols and triols, such as, among others, ethylene glycol, propylene glycol, butane-1,3-diol, butane-1,4-diol, hexane-1,6-diol, neopentyl glycol, diethylene glycol, dipropylene glycol, pentaerythritol, glycerol, diglycerol, trimethylolpropane, cyclohexanediol, sugars such as sucrose, and similar low molecular weight polyols, or combinations thereof. In another embodiment, the polyol component comprises an amine polyether polyol that can be produced when an amine, such as ethylenediamine, diethylenetriamine, tolylenediamine, diphenylmethanediamine, triethanolamine, or the like, is reacted with ethylene oxide or propylene oxide. In one embodiment for spray foam formulations, the polyol component comprises a polyether polyol, which results in improved reactivity of the polyurethane composition.

[0014] In one embodiment, the polyether polyol is prepared by the condensation of phenol with formaldehyde in the presence of a hydroxyl-containing amine, such as diethanolamine, ethanolamine, etc.

[0015] Polyether polyols are prepared from one or more alkylene oxides having 2 to 4 carbon atoms in the alkylene group by known processes, for example, by anionic polymerization using an alkali metal hydroxide, such as sodium hydroxide or potassium hydroxide, or an alkali metal alkoxide, such as sodium methoxide, sodium methoxide, or potassium isopropoxide, as catalyst, with the addition of at least one starter molecule having 2 to 8, preferably 2 to 6, reactive hydrogen atoms, or by cationic polymerization using a Lewis acid, such as, in particular, antimony pentachloride, boron fluoride etherate, or fuller's earth, as catalyst. Suitable polyether polyols can also be prepared using DMC catalysts.

[0016] Examples of suitable alkylene oxides are tetrahydrofuran, 1,3-propylene oxide, 1,2- and 2,3-butylene oxide, styrene oxide, preferably ethylene oxide and 1,2-propylene oxide. The alkylene oxides may be used individually, alternating successively, or as mixtures. Preferred alkylene oxides are propylene oxide and ethylene oxide; propylene oxide is particularly preferred.

[0017] Examples of useful starter molecules include: water, organic dicarboxylic acids such as succinic acid, adipic acid, phthalic acid and terephthalic acid, aliphatic and aromatic, optionally N-monoalkyl-, and N,N- and N,N'-dialkyl-substituted diamines having 1 to 4 carbon atoms in the alkyl group, such as optionally mono- and dialkyl-substituted ethylenediamine, diethylenetriamine, triethylenetetramine, propylene-1,3-diamine, butylene-1,3- or -1,4-diamine, hexamethylene-1,2-, -1,3-, -1,4-, -1,5- and -1,6-diamine, phenylenediamine, tolylene-2,3-, -2,4- and -2,6-diamine and 4,4'-, 2,4'- and 2,2'-diaminodiphenylmethane.

[0018] Useful starter molecules further include: alkanolamines, such as ethanolamine, N-methyl- and N-ethylethanolamine, dialkanolamines, such as diethanolamine, N-methyl- and N-ethyldiethanolamine, and trialkanolamines, such as triethanolamine, and ammonia.

[0019] It is preferred to use dihydric or polyhydric alcohols such as ethanediol, propane-1,2- and -1,3-diol, diethylene glycol, dipropylene glycol, butane-1,4-diol, hexane-1,6-diol, glycerol, trimethylolpropane, pentaerythritol, sorbitol and sucrose, and in particular the above-mentioned primary amines, such as tolylene-2,3-diamine.

[0020] The polyether polyols, preferably polyoxypropylene polyols and / or polyoxyethylene polyols, preferably have a functionality of 2 to 6, in particular 2 to 5, and a number average molecular weight of 150 to 3000, preferably 200 to 1500, in particular 250 to 750.

[0021] Suitable polyester polyols can be prepared, for example, from organic dicarboxylic acids having 2 to 12 carbon atoms, preferably aromatic dicarboxylic acids, or mixtures of aromatic and aliphatic dicarboxylic acids, and polyhydric alcohols having 2 to 12 carbon atoms, preferably 2 to 6 carbon atoms, preferably diols. Examples of useful dicarboxylic acids include succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, and terephthalic acid. The dicarboxylic acids can be used alone or in mixtures. Instead of the free dicarboxylic acids, it is also possible to use corresponding dicarboxylic acid derivatives, such as dicarboxylic acid esters of alcohols having 1 to 4 carbon atoms or dicarboxylic acid anhydrides. The aromatic dicarboxylic acids used are preferably phthalic acid, phthalic anhydride, terephthalic acid, and / or isophthalic acid, either alone or in mixtures. The aliphatic dicarboxylic acid used is preferably a dicarboxylic acid mixture of succinic acid, glutaric acid, and adipic acid, for example in a quantitative ratio of 20-35:35-50:20-32 parts by weight, especially adipic acid. Examples of di- and polyhydric alcohols, especially diols, are ethanediol, diethylene glycol, propane-1,2- and -1,3-diol, dipropylene glycol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, decane-1,10-diol, glycerol, trimethylolpropane, and pentaerythritol. It is preferred to use ethanediol, diethylene glycol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, or a mixture of at least two of the aforementioned diols, especially a mixture of butane-1,4-diol, pentane-1,5-diol, and hexane-1,6-diol. It is also possible to use polyester polyols derived from lactones, such as ε-caprolactone, or from hydroxycarboxylic acids, such as ω-hydroxycaproic acid.

[0022] For the preparation of polyester polyols, biobased starting materials and / or their derivatives, such as castor oil, palm oil, polyhydroxy fatty acids, ricinoleic acid, hydroxy-modified oils, grapeseed oil, black cumin oil, pumpkin seed oil, borage seed oil, soybean oil, wheat germ oil, rapeseed oil, sunflower seed oil, peanut oil, apricot kernel oil, pistachio nut oil, almond oil, olive oil, macadamia nut oil, avocado oil, sea buckthorn, It is also possible to use hydroxy-modified fatty acids and fatty acid esters based on oil, sesame oil, hemp oil, hazelnut oil, evening primrose oil, wild rose oil, safflower oil, walnut oil, myristoleic acid, palmitoleic acid, stearic acid, palmitic acid, oleic acid, vaccenic acid, petroselinic acid, gadoleic acid, erucic acid, nervonic acid, linoleic acid, α- and γ-linolenic acid, stearidonic acid, arachidonic acid, thymnodonic acid, clupanodonic acid and cervonic acid.

[0023] Preferred polyester polyols are prepared from adipic acid, phthalic anhydride and / or terephthalic anhydride as dicarboxylic acids, propylene glycol, dipropylene glycol, ethylene glycol, diethylene glycol, glycerol and / or trimethylolpropane as alcohol components, and oleic acid or castor oil, and have an OH number of 150 to 400 and a functionality of 2 to 4.5.

[0024] The polyol mixture comprises as catalyst D an imidazolium salt of general formula (I).

[0025] R1 and R2 in formula (I) are each independently an aliphatic, alicyclic, araliphatic, or aromatic organic group having 1 to 10 carbon atoms. Examples of the hydrocarbon group include a phenyl group, a benzyl group, a phenyl group or a benzyl group substituted with one or more C1-C4 alkyl groups such as a mesityl group, as well as alkyl and alkenyl groups, particularly alkyl groups.

[0026] Preferably, R1 and R2 are independently a C1-C18 alkyl group, preferably a C1-C16 alkyl group, more preferably a C1-C14 alkyl group, even more preferably a C1-C12 alkyl group, particularly preferably a C1-C10 alkyl group. Very particularly preferably, R1 and R2 are independently a C1-C6 alkyl group, especially a C1-C4 alkyl group. Particularly preferably, R1 and R2 are independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl or tert-butyl, of which methyl, ethyl, n-propyl and n-butyl are particularly preferred.

[0027] Examples of imidazolium ions include 1,3-dimethylimidazolium (DMIM), 1-benzyl-3-methylimidazolium, 3-ethyl-1-methylimidazolium (EMIM), 1-propyl-3-methylimidazolium, 3-n-butyl-1-methylimidazolium, 1-hexyl-3-methylimidazolium, 1-methyl-3-octylimidazolium, 1-decyl-3-methylimidazolium, 1-dodecyl-3-methylimidazolium, 1,3-diethylimidazolium (DEIM), 1,3-diisopropylimidazolium, 1,3-di-n-butylimidazolium, and 1,3-dihexylimidazolium.

[0028] Preferred imidazolium ions are 1,3-dimethylimidazolium (DMIM), 3-ethyl-1-methylimidazolium (EMIM), and 1,3-diethylimidazolium (DEIM), with 1,3-dimethylimidazolium (DMIM) and 1,3-diethylimidazolium (DEIM) being particularly preferred.

[0029] The carboxylate anion A- in formula (I) may be the anion of an aliphatic or aromatic carboxylic acid having 1 to 20 carbon atoms, preferably the anion of an aliphatic carboxylic acid having 1 to 20 carbon atoms.

[0030] Examples of anions of aromatic carboxylic acids are benzoate, salicylate, and nicotinate. The alkanoate anion, i.e., the anion of an alkanecarboxylic acid, may be linear or branched, preferably linear. The parent alkanecarboxylic acid has 1 to 20 carbon atoms, preferably 2 to 18, and more preferably 2 to 12 carbon atoms.

[0031] Examples of alkanoate anions are formate, acetate, propionate, 2,2-dimethylpropionate (pivalate), n-butanoate, isobutanoate, n-pentanoate, n-hexanoate, n-heptanoate, n-octanoate, 2-ethylhexanoate, isooctanoate, n-nonanoate, isononanoate, n-decanoate, 3-propylheptanoate, These include n-dodecanoate, tetradecanoate, hexadecanoate, stearate, n-eicosanoate, with acetate, formate, propionate, n-butanoate, isobutanoate, n-pentanoate, 2,2-dimethylpropionate (pivalate) and n-hexanoate being preferred, with acetate, formate and propionate being particularly preferred, and acetate being especially preferred.

[0032] The catalysts used in accordance with the present invention are suitable for the production of rigid insulating foams, particularly for spray foam applications, equipment insulation, insulating building panels, and other insulation products composed of closed-cell rigid polyurethane foam. The present invention encompasses foams having an Isocyanate Index of 70 to 500, 90 to 270, and typically 100 to 150. The catalysts used in accordance with the present invention may be used in combination with any halogenated blowing agent to provide improved system stability, and are particularly suitable for improving the stability of systems containing hydrohaloolefin blowing agents, particularly HFCO-1234ze (trans-1,3,3,3-tetrafluoroprop-1-ene) and HFCO-1233zd (1-chloro-3,3,3-trifluoropropene).

[0033] As one or more additives E, the polyol mixture may include a cell stabilizer, a chain extender, a pigment, a filler, an organic acid or diacid, a flame retardant, an additional urethane gelling catalyst, an additional urethane foam catalyst, a transition metal catalyst, or a combination thereof.

[0034] Suitable foam stabilizers include silicone surfactants, anionic surfactants, cationic surfactants, zwitterionic surfactants, nonionic surfactants, and combinations thereof. In one embodiment, the foam stabilizer is a silicone surfactant, such as a polyalkylsiloxane, a polyoxyalkylene polyol-modified dimethylpolysiloxane, or an alkylene glycol-modified dimethylpolysiloxane. In another embodiment, the foam stabilizer is an anionic surfactant, such as a salt of a fatty acid, a salt of a sulfate ester, a salt of a phosphoric acid ester, a salt of a sulfonic acid, or a combination thereof. Suitable cationic surfactants include quaternary ammonium salts (pH-dependent or permanently charged), such as cetyltrimethylammonium chloride, cetylpyridinium chloride, polyethoxylated tallowamine, benzalkonium chloride, benzethonium chloride, and the like. Suitable zwitterionic or amphoteric surfactants include sultaines, amino acids, imino acids, betaines, and phosphates. Suitable nonionic surfactants include fatty alcohols, polyoxyethylene glycol alkyl ethers, polyoxypropylene glycol alkyl ethers, glucosides (e.g., decyl, lauryl, and octyl glucoside), polyoxyethylene glycol alkyl phenol ethers, glycol alkyl esters, etc. The polyol mixture may also include a foam stabilizer in an amount of, for example, 0.1% to 20% by weight.

[0035] Suitable pigments are organic pigments, inorganic pigments, or combinations thereof. In certain embodiments where the pigment is an organic pigment, the pigment is an azo / diazo dye, a phthalocyanine, a dioxazine, carbon black, or a combination thereof. In other embodiments where the pigment is an inorganic pigment, the pigment is titanium dioxide, iron oxide, chromium oxide, or a combination thereof. The polyol mixture may include, for example, an amount of pigment ranging from 0.1% to 10% by weight.

[0036] Suitable fillers increase the density and load-bearing capacity of the polyurethane foam. In certain embodiments, the filler is barium sulfate, calcium carbonate, or a combination thereof. The polyol mixture may include the filler in an amount of, for example, 0.1% to 20% by weight.

[0037] Suitable flame retardants include, for example, chlorinated phosphate esters, phosphate esters, chlorinated paraffins, melamine powders, or combinations thereof. The polyol mixture may contain, for example, 0.1% to 30% by weight of the flame retardant.

[0038] The polyol mixture generally comprises: a) as component A, 10% by weight to 99.7% by weight, preferably 35% by weight to 97% by weight, of at least one polyol; b) 0.1% to 30% by weight, preferably 1% to 15% by weight, of a hydrohaloolefin blowing agent as component B; c) 0.1% by weight to 10% by weight, preferably 0.5% by weight to 5% by weight of water as component C; d) 0.1% by weight to 10% by weight, preferably 0.5% by weight to 5% by weight of an imidazolium salt catalyst of general formula (I) as component D; e) optionally, one or more components E in an amount of 0% to 80% by weight, preferably 1% to 40% by weight, of one or more further additives.

[0039] The present invention further comprises: (i) an organic or modified organic polyisocyanate, (ii) Polyol Mixture of the Present Invention and a method for producing a rigid polyurethane foam by reacting the

[0040] Useful organic polyisocyanates (i) are the aliphatic, cycloaliphatic, araliphatic, and preferably aromatic polyfunctional isocyanates known per se. The organic polyisocyanates may optionally be modified.

[0041] Specific examples include: alkylene diisocyanates having 4 to 12 carbon atoms in the alkylene group, such as dodecane 1,12-diisocyanate, 2-ethyltetramethylene 1,4-diisocyanate, 2-methylpentamethylene 1,5-diisocyanate, tetramethylene 1,4-diisocyanate, and preferably hexamethylene 1,6-diisocyanate; alicyclic diisocyanates, such as cyclohexane 1,3- and 1,4-diisocyanate, as well as mixtures of these isomers, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (IPDI), hexahydrotolylene 2,4- and 2,6-diisocyanate, as well as the corresponding isomer mixtures, dicyclohexane Examples of suitable organic diisocyanates include 4,4'-, 2,2'-, and 2,4'-diisocyanates, as well as corresponding isomer mixtures, and preferably aromatic di- and polyisocyanates, such as tolylene 2,4- and 2,6-diisocyanate and corresponding isomer mixtures, diphenylmethane 4,4'-, 2,4'-, and 2,2'-diisocyanate and corresponding isomer mixtures, mixtures of diphenylmethane 4,4'- and 2,2'-diisocyanates, polyphenylpolymethylene polyisocyanates, mixtures of diphenylmethane 2,4'-, 2,4'-, and 2,2'-diisocyanates and polyphenylpolymethylene polyisocyanates (crude MDI), and mixtures of crude MDI and tolylene diisocyanate. The organic diisocyanates and polyisocyanates may be used alone or in the form of mixtures thereof.

[0042] Preferred polyisocyanates are tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and especially mixtures of diphenylmethane diisocyanate and polyphenylene polymethylene polyisocyanate (polymeric MDI or PMDI).

[0043] Modified polyfunctional isocyanates, i.e., products obtained by chemical reaction of organic polyisocyanates, are also commonly used. Examples include polyisocyanates containing ester, urea, biuret, allophanate, carbodiimide, isocyanurate, uretdione, carbamate, and / or urethane groups.

[0044] It is very particularly preferred to use polymeric MDI for the production of the rigid polyurethane foams of the present invention.

[0045] The present invention also relates to the use of the imidazolium salts of general formula (I) as catalysts for producing rigid polyurethane foams in polyol mixtures containing hydrohaloolefin blowing agents.

[0046] The present invention will be clarified in more detail by the following examples. [Example]

[0047] Ingredients used: Lupranol 3300: Polyether triol with an OH value of 400 mg KOH / g Foam stabilizer: Silicone Blowing agent: R-1233zd(E) = 1-chloro-3,3,3-trifluoro-1-propene Lupranat M20S: Polymer MDI, NCO 31.5%, viscosity 210 mPa·s

[0048] Method 1 A polyol mixture is prepared by mixing 100 g of Lupranol 3300, 4 g of water, and 2 g of foam stabilizer. 15 g of this mixture, plus 1 wt. % of catalyst, is mixed with 17.1 g of Lupranat M20S in a 0.5 L plastic beaker using a propeller stirrer at 2000 rpm for 5 seconds and measured.

[0049] The following parameters were measured: Cream time: the time it takes for the PU mixture to start foaming; Half height: time to reach half the height of the beaker (7 cm); time to reach the edge of the beaker; Time to end of foaming; Form height.

[0050] The results are shown in Table 1.

[0051] Method 2 For this purpose, a stock solution consisting of Lupranol 3300, foam stabilizer, and water was prepared. This stock solution, containing 50 g of Lupranol 3300, 1 g of foam stabilizer, and 1 g of water, was weighed into 500 mL pressure-resistant laboratory glass bottles (52 g per bottle), to which 1 g of catalyst and 7.5 g of blowing agent R-1233zd(E) were added. The bottles were stored at 45°C for 2 and 4 weeks. From each bottle, 17 g of the polyol mixture was mixed with 17.1 g of Luprat M20S in a 0.5 L plastic beaker using a propeller stirrer at 2000 rpm for 5 seconds and then measured.

[0052] The following parameters were measured: Foaming start time: the time it takes for the PU mixture to start foaming; Half height: time to reach half the height of the beaker (7 cm); time to reach the edge of the beaker; Time to end of foaming; Form height.

[0053] The results are shown in Table 2.

[0054] As can be seen from Table 2, BDMAEE exhibits poor storage stability in the presence of R-1233zd(E).

[0055] DMI is not completely harmless from a toxicological point of view (skin sensitization).

[0056] [Table 1]

[0057]

Table 2

[0058]

Table 3

[0059]

Table 4

Claims

1. a) as component A, 10% to 99.7% by weight of at least one polyol; b) 0.1 wt. % to 30 wt. % of a hydrohaloolefin blowing agent as component B; c) 0.1% by weight to 10% by weight of water as component C; d) 0.1% by weight to 10% by weight of a catalyst as component D; e) optionally, as one or more further components E, from 0% to 80% by weight of one or more further additives; Including, Catalyst D is an imidazolium salt of general formula (I) 【Chemical 1】 wherein R1 and R2 are independently an aliphatic, alicyclic, araliphatic, or aromatic group having 1 to 20 carbon atoms, which may further contain one or more heteroatoms; A- is a carboxylate anion having 1 to 20 carbon atoms, which may further contain one or more additional heteroatoms.

2. 2. The polyol mixture of claim 1, wherein the hydrohaloolefin blowing agent comprises trans-1-chloro-3,3,3-trifluoropropene.

3. 3. The polyol mixture according to claim 1, wherein R1 and R2 in the general formula (I) are selected from methyl and ethyl.

4. 4. The polyol mixture according to claim 1, wherein the carboxylate anion A- is selected from the group consisting of formate, acetate, propionate, 2,2-dimethylpropionate (pivalate), n-butanoate, isobutanoate, n-pentanoate, n-hexanoate, n-heptanoate, n-octanoate, 2-ethylhexanoate, isooctanoate, n-nonanoate, isononanoate, n-decanoate, 3-propylheptanoate, n-dodecanoate, tetradecanoate, hexadecanoate, stearate, and n-eicosanoate.

5. 5. The polyol mixture according to claim 1, wherein the carboxylate anion A- is acetate.

6. The polyol mixture of any one of claims 1 to 5, wherein polyol A comprises a polyether polyol and optionally a polyester polyol.

7. 7. The polyol mixture of claim 1, wherein the one or more further additives E are selected from a cell stabilizer, a chain extender, a pigment, a filler, an organic acid or diacid, a flame retardant, an additional urethane gelling catalyst, an additional urethane foam catalyst, a transition metal catalyst, or a combination thereof.

8. Use of the polyol mixture according to any one of claims 1 to 7 for spray foam applications.

9. 9. Use according to claim 8 for producing rigid insulating foams.

10. 10. Use according to claim 9 for equipment insulation.

11. 1. A method for producing a rigid polyurethane foam having an isocyanate index of 70 to 500, comprising: (i) an organic or modified organic polyisocyanate, (ii) The polyol mixture according to any one of claims 1 to 7 A method by reacting with

12. Imidazolium salts of general formula (I) 【Chemistry 2】 wherein R1 and R2 are independently an aliphatic, alicyclic, araliphatic, or aromatic group having 1 to 20 carbon atoms, which may further contain one or more heteroatoms; A- is a carboxylate anion having 1 to 20 carbon atoms, which may further contain one or more additional heteroatoms; 8. Use as a catalyst in a polyol mixture according to any one of claims 1 to 7 containing a hydrohaloolefin blowing agent for producing rigid polyurethane foams.

13. The use of claim 12, wherein the hydrohaloolefin blowing agent comprises trans-1-chloro-3,3,3-trifluoropropene.

14. The use according to claim 12 or 13, wherein R1 and R2 in the general formula (I) are selected from methyl and ethyl.

15. A in formula (I) － The use according to any one of claims 12 to 14, wherein is acetate.

16. Use according to any one of claims 12 to 15 in spray foam applications.

17. 17. Use according to claim 16 for producing rigid insulating foams.

18. 18. Use according to claim 17 for equipment insulation.

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