Improving storage stability of hydrofluoroolefins in amine-containing polyol components for polyurethane production

Abstract

The present invention relates to a polyol component for producing polyurethane foam, the polyol component comprising: (a) a compound having at least two isocyanate-reactive hydrogen atoms; (b) at least one polyurethane catalyst (b1) containing at least one tertiary nitrogen atom, the tertiary nitrogen atom being part of an aliphatic or aromatic ring and / or bonded to at least one secondary carbon atom; and at least one polyurethane catalyst (b2) selected from the group consisting of cyclic amides, wherein the polyurethane catalysts (b1) and (b2) do not have a dimethylamino group bonded to a primary carbon atom; (c) a blowing agent comprising a hydrofluoroolefin; and (d) optional additives. The present invention also relates to a process for producing polyurethane foam, which comprises mixing the polyol component with an isocyanate component comprising at least one polyisocyanate to form a reaction mixture and convert the resulting mixture into a polyurethane, and to the polyurethane foam obtained by such a process.

Description

[Technical Field]

[0001] The present invention provides a polyol component for producing polyurethane foams, comprising: (a) a compound having at least two isocyanate-reactive hydrogen atoms; (b) at least one polyurethane catalyst (b1) containing at least one tertiary nitrogen atom, the tertiary nitrogen atom being part of an aliphatic or aromatic ring and / or bonded to at least one secondary carbon atom; and at least one polyurethane catalyst (b2) selected from the group consisting of cyclic amides, wherein the polyurethane catalysts (b1) and (b2) do not have a dimethylamino group bonded to a primary carbon atom; and (c) at least one aliphatic halogenated hydrocarbon compound (c11) of the general formula (1): [ka] [In the formula, the group R 1 ~R 4 represent, in each case independently of one another, a hydrogen group, a fluoride group, a chloride group, a methyl group or an ethyl group, the hydrogen atoms of the methyl or ethyl groups being completely or partially substituted by chloride or fluoride, with the proviso that the compound according to formula (1) consists of 2 to 5 carbon atoms, at least one hydrogen atom and at least two halogen atoms selected from fluorine and chlorine atoms, and the group R 1 and R 4 and at least one of the groups R 2 and R 3wherein at least one of the carbon-carbon double bonds has at least one halogen atom, and the carbon atom of the carbon-carbon double bond having a methyl or ethyl group further has a hydrogen atom, and (d) optionally an additive. The present invention further includes a method for producing polyurethane foam, which comprises mixing such a polyol component with an isocyanate component comprising at least one polyisocyanate to form a reaction mixture and converting the polyol component into a polyurethane, and the polyurethane foam obtained by such a method.

[0002] The production of polyurethane foams, particularly polyurethane foams, is well known. In polyurethane production, the reaction of an isocyanate with a polyol is typically carried out in the presence of a catalyst, particularly a strongly basic amine catalyst, a blowing agent, and additional auxiliaries and additives. The starting materials are often combined by a supplier, usually a chemical company, to tailor the materials to the application and achieve the desired polyurethane properties. For this purpose, an isocyanate component containing an isocyanate and a polyol component containing an isocyanate-reactive component are typically blended together, so that the user simply mixes the two components to initiate the reaction and form the desired polyurethane.

[0003] Blowing agents are used to produce polyurethane foams. Chemical blowing agents, such as water or carboxylic acids, and physical blowing agents can be used. Physical blowing agents are often used in combination with chemical blowing agents, particularly for the production of rigid polyurethane foams. Chemical blowing agents are compounds that react with isocyanates to form gas (usually carbon dioxide). Physical blowing agents are usually low-boiling liquids that evaporate due to the heat of reaction during the reaction between isocyanates and polyols, thereby causing foaming of the reaction mixture. Due to the high reactivity of isocyanates, physical blowing agents are also added to the polyol component to avoid side reactions.

[0004] Chlorofluorocarbons were once the primary physical blowing agents. However, these have now been banned in many parts of the world due to their ozone-depleting effects. Currently, fluorinated hydrocarbons (HFCs) and low-boiling hydrocarbons such as pentane are the primary physical blowing agents. One criterion for this is the storage stability of each component.

[0005] Due to the non-polar nature of hydrocarbons, mainly pentane, these blowing agents have limited solubility in polyurethane systems, and therefore in many polyurethane systems the polyol component tends to separate, so that it is advantageous to meter in the blowing agent only shortly before the foaming process to avoid the problem of short storage stability of the polyol component with added blowing agent, but this increases the complexity for the user.

[0006] Another problem with using alkanes as blowing agents is their flammability, which increases the flammability of the resulting polyurethane foam. Furthermore, the components containing alkanes as blowing agents, usually the polyol components, are also highly flammable. This necessitates special care when storing and processing systems containing alkanes as blowing agents. Furthermore, partial release of alkanes can occur during the foaming process. The resulting explosion hazard requires significant investments in safety equipment.

[0007] When the investment in safety equipment for using hydrocarbons as physical blowing agents is too expensive or not feasible due to capital constraints, fluorinated hydrocarbons (HFCs) are used. HFCs have the added advantage over hydrocarbons that they can provide foams with higher thermal insulation. However, HFCs have been criticized from an environmental perspective due to their contribution to global warming, i.e., their high "global warming potential," and therefore their use is currently being reduced and potentially banned in the EU through regulatory requirements.

[0008] Therefore, preferred physical blowing agents have low global warming potential. This is an advantage of halogenated olefins, also known as HFOs (hydrofluoroolefins). A drawback of HFO-containing polyol components, especially those containing special HFOs such as HFO-1234ze and / or HCFO-1233zd, is the storage stability of the polyol component. For example, even short-term storage of HFO-containing polyol components can result in significant changes in the reaction profile, resulting in significantly reduced foam quality and even foam collapse. The poor storage stability is due to the decomposition of the blowing agent in the polyol component. This is described, for example, in WO 2009048807. The decomposition reaction of HFO blowing agents can be delayed by using certain catalysts, such as imidazole derivatives, but this limits formulation flexibility and significantly impairs, if not makes it impossible, to achieve optimal catalyst settings.

[0009] There are several approaches to improve the storage stability of polyol components containing halogenated olefins as blowing agents. Most approaches are based on either blocking the amine catalyst or using alternative catalysts, such as metal catalysts. Furthermore, optimized amine catalysts that have only a slight effect on the storage stability of polyol components, for example, due to steric hindrance, have also been described. One example is WO2009048807, which discloses a polyol component containing a sterically hindered amine catalyst. However, in most cases, such catalysts are expensive.

[0010] WO 2018170107 discloses the use of metal catalysts as a substitute for strongly basic amine catalysts. However, metal catalysts are strong gel catalysts and cannot be used to optimize the reaction profile as a substitute for blowing catalysts, so using metal catalysts instead of amine catalysts is not advisable. Furthermore, many metal catalysts are not sufficiently stable against hydrolysis, so they have poor storage stability in polyol components containing water, and some metal catalysts can only be used in limited applications due to regulatory requirements.

[0011] WO 2009048826 describes the use of blocked amine catalysts, and U.S. Patent Application Publication No. 20190119461 discloses the use of imidazole-based catalysts. The drawbacks of these catalysts are that they often have low activity, and furthermore, blocked catalysts usually only unblock at relatively high temperatures. This requires an additional step of heating the reaction mixture, limiting the flexibility to tailor the reaction profile.

[0012] The object of the present invention was to provide a storage-stable polyol component which does not have the above-mentioned drawbacks and which contains an HFO blowing agent and which has a catalyst which is particularly inexpensive and capable of catalyzing a balanced gelling reaction and a blowing reaction.

[0013] The object of the present invention is to provide a polyol component for producing polyurethane foam, comprising: (a) a compound having at least two isocyanate-reactive hydrogen atoms; (b) at least one polyurethane catalyst (b1) containing at least one tertiary nitrogen atom, the tertiary nitrogen atom being part of an aliphatic or aromatic ring and / or bonded to at least one secondary carbon atom; and at least one polyurethane catalyst (b2) selected from the group consisting of cyclic amides, wherein the polyurethane catalysts (b1) and (b2) do not have a dimethylamino group bonded to a primary carbon atom; and (c) at least one aliphatic halogenated hydrocarbon compound (c11) of general formula (1): [ka] [In the formula, the group R 1 ~R 4represent, in each case independently of one another, a hydrogen group, a fluoride group, a chloride group, a methyl group or an ethyl group, the hydrogen atoms of the methyl or ethyl groups being completely or partially substituted by chloride or fluoride, with the proviso that the compound according to formula (1) consists of 2 to 5 carbon atoms, at least one hydrogen atom and at least two halogen atoms selected from fluorine and chlorine atoms, and the group R 1 and R 4 and at least one of the groups R 2 and R 3 wherein at least one of the carbon-carbon double bonds has at least one halogen atom, and the carbon atom of the carbon-carbon double bond having a methyl or ethyl group further has a hydrogen atom, and (d) optionally an additive. The present invention further encompasses a method for producing a polyurethane foam, which comprises mixing such a polyol component with an isocyanate component including at least one polyisocyanate to form a reaction mixture and converting the polyol component into a polyurethane, and a polyurethane foam obtainable by such a method.

[0014] Polyurethanes in the sense of the present invention include all known polyisocyanate polyaddition products. These include addition products of isocyanates and alcohols, as well as modified polyurethanes that may contain isocyanurate structures, allophanate structures, urea structures, carbodiimide structures, uretonimine structures, biuret structures, and further isocyanate addition products. Polyurethanes are polyurethane foams. These polyurethane foams according to the present invention include, in particular, flexible foams, semi-rigid foams, rigid foams, or molded foams.

[0015] In the context of the present invention, polyurethane foams are understood to mean foams according to DIN 7726. Flexible polyurethane foams according to the present invention have a compressive stress or compressive strength at 10% compression according to DIN 53 421 / DIN EN ISO 604 of 15 kPa or less, preferably 1 to 14 kPa, in particular 4 to 14 kPa. Semi-rigid polyurethane foams according to the present invention have a compressive stress at 10% compression according to DIN 53 421 / DIN EN ISO 604 of more than 15 kPa but less than 80 kPa. According to DIN ISO 4590, semi-rigid and flexible polyurethane foams according to the present invention preferably have an open cell content of more than 85%, particularly preferably more than 90%. Further details regarding the polyurethane flexible and polyurethane semi-rigid foams according to the invention can be found in "Kunststoffhandbuch, Band 7, Polyurethane", Carl Hanser Verlag, 3. Auflage 1993, Kapitel 5.

[0016] The polyurethane rigid foams according to the invention have a compressive stress at 10% compression of at least 80 kPa, preferably at least 120 kPa, particularly preferably at least 150 kPa. Furthermore, the polyurethane rigid foams have a closed cell content of more than 80%, preferably more than 90%, according to DIN ISO 4590. Further details regarding the polyurethane rigid foams according to the invention can be found in "Kunststoffhandbuch, Band 7, Polyurethane", Carl Hanser Verlag, 3. Auflage 1993, Kapitel 6.

[0017] In the context of this invention, elastomeric polyurethane foam is understood to mean a polyurethane foam according to DIN 7726 which, after a short deformation of 50% of its thickness according to DIN 53 577, does not show a permanent deformation of more than 2% of its initial thickness after 10 minutes. This can be, for example, a polyurethane flexible foam.

[0018] Polyurethane molded foams are polyurethane foams according to DIN 7726 that, due to the shaping process, have skins or edge zones that are denser than the core. The average bulk density of the entire core and edge zones can range from 15 to 800 g / L. Molded foams with a density of more than 100 g / L are usually called integral foams. Polyurethane molded foams within the meaning of the present invention can be polyurethane rigid foams, polyurethane semi-rigid foams, or polyurethane flexible foams. Further details regarding polyurethane integral foams according to the present invention can be found in "Kunststoffhandbuch, Band 7, Polyurethane," Carl Hanser Verlag, 3. Auflage 1993, Kapitel 7. The polyurethane according to the present invention is preferably a polyurethane foam, particularly preferably a polyurethane rigid foam, polyurethane semi-rigid foam, or polyurethane flexible foam, and especially a polyurethane rigid foam.

[0019] The isocyanate-reactive compound (a) can be any compound known in polyurethane chemistry that has an isocyanate-reactive group, preferably one having at least one hydroxyl, -NH, or -NH2, or carboxylic acid group, and more preferably one having at least one NH2 or OH group, in particular one having at least one -OH group. The functionality of the isocyanate group can be in the range of 1 to 8, preferably 2 to 8. The isocyanate-reactive compound can be a polyether polyol (a1), a polyester polyol (a2), or a mixture thereof, preferably polyesterol (a2), or a mixture of polyetherol (a1) and polyesterol (a2). The polyetherol (a1) and polyesterol (a2) preferably have a number-average molecular weight of 150 to 15,000 g / mol, preferably 150 to 5,000 g / mol, and particularly preferably 200 to 2,000 g / mol. In addition to the polyetherols and polyesterols, low molecular weight chain extenders and / or crosslinkers known, for example, in polyurethane chemistry, can also be used. Advantageously, compound (a) has a number-average molecular weight of 62 to 15,000 g / mol. Advantageously, compound (a) has a number-average functionality of at least 1.7, particularly preferably at least 2.0. According to the present invention, polyetherols (a1) and / or polyesterols (a2) have a number-average functionality of at least 1.7, more preferably at least 2.0.

[0020] The polyetherols (a1) are prepared, for example, from epoxides such as propylene oxide and / or ethylene oxide, or tetrahydrofuran, with hydrogen-active starter compounds such as aliphatic alcohols, phenols, amines, carboxylic acids, water, or compounds based on natural substances such as sucrose, sorbitol, or mannitol, using a catalyst, such as a basic catalyst or a double metal cyanide catalyst, as described in PCT / EP2005 / 010124, EP 90444, or WO 05 / 090440.

[0021] Polyesterols (a2) are prepared, for example, from aliphatic or aromatic dicarboxylic acids and polyhydric alcohols, polythioether polyols, polyesteramides, hydroxyl-containing polyacetals and / or hydroxyl-containing aliphatic polycarbonates, preferably in the presence of an esterification catalyst. Further possible polyols are described, for example, in "Kunststoffhandbuch, Band 7, Polyurethane", Carl Hanser Verlag, 3. Auflage 1993, Kapitel 3.1.

[0022] According to the present invention, the isocyanate-reactive compound (a) comprises at least one polyether polyol (a1) and / or at least one polyester polyol (a2), advantageously at least one polyester polyol (a2), optionally in combination with at least one polyether polyol (a1). Advantageously, the weight proportion of polyether polyol (a1) is 0 to 30% by weight, particularly preferably 0 to 20% by weight, and in particular 1 to 15% by weight, and the weight proportion of polyester polyol (a2) is advantageously 70 to 100% by weight, particularly preferably 80 to 100% by weight, and in particular 85 to 99% by weight, in each case based on the total weight of polyether polyol (a1) and polyester polyol (a2). In the context of the present disclosure, the terms "polyester polyol" and "polyester polyol" have the same meaning as the terms "polyether polyol" and "polyether polyol".

[0023] Polyetherols (a1) can be obtained by anionic polymerization of alkylene oxides in the presence of a catalyst, for example, by adding at least one starter molecule containing 1 to 8, preferably 2 to 6, reactive hydrogen atoms, or a mixture of starter molecules containing an average of 1.5 to 8, preferably 2 to 6, reactive hydrogen atoms in all starters present. If a mixture of starter molecules with different functionalities is used, partial functionality can be achieved. For example, the influence of side reactions on functionality is not taken into account in the nominal functionality. Catalysts that can be used include alkali metal hydroxides such as sodium hydroxide or potassium hydroxide, alkali metal alcoholates such as sodium methylate, sodium or potassium ethylate, or potassium isopropylate, or, in the case of cationic polymerization, Lewis acids such as antimony pentachloride, boron trifluoride etherate, or bleaching earth. Aminic alkoxylation catalysts such as dimethylethanolamine (DMEOA), imidazole, and imidazole derivatives can also be used. Furthermore, double metal cyanide compounds, so-called DMC catalysts, can also be used as catalysts.

[0024] Advantageously, the alkylene oxide used is one or more compounds having 2 to 4 carbon atoms in the alkylene group, such as tetrahydrofuran, 1,2-propylene oxide, ethylene oxide, 1,2- or 2,3-butylene oxide, in each case alone or in the form of a mixture. Advantageously, ethylene oxide and / or 1,2-propylene oxide, particularly preferably ethylene oxide, is used.

[0025] Examples of starter molecules include hydroxyl group-containing or amine group-containing compounds, such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, bisphenol A, bisphenol F, glycerin, trimethylolpropane, pentaerythritol, sugar derivatives such as sucrose, hexitol derivatives such as sorbitol, methylamine, ethylamine, isopropylamine, butylamine, benzylamine, aniline, toluidine, and toluenediamine (TD). Suitable co-starters include naphthylamine, ethylenediamine, methylenedianiline, 2,2'-diaminodiphenylmethane (2,2-MDA), 2,4'-diaminodiphenylmethane (2,4-MDA), 4,4'-diaminodiphenylmethane (4,4-MDA), diethylenetriamine, 4,4'-methylenedianiline, 1,3-propanediamine, 1,6-hexanediamine, ethanolamine, diethanolamine, triethanolamine, and other dihydric or polyhydric alcohols or monohydric or polyhydric amines, or water. Because highly functional compounds often exist in solid form under typical alkoxylation reaction conditions, they are typically alkoxylated with a co-starter. Suitable co-starters include, for example, water, polyfunctional lower alcohols such as glycerin, trimethylolpropane, pentaerythritol, diethylene glycol, ethylene glycol, propylene glycol, and their homologues. Further co-starters that come into consideration are, for example, organic fatty acids or monofunctional fatty alcohols, fatty acid monoesters or fatty acid methyl esters, such as oleic acid, stearic acid, oleic acid methyl ester, stearic acid methyl ester or biodiesel, which serve to improve the solubility of the blowing agent in the production of polyisocyanurate rigid foams.

[0026] Preferred starter molecules (a1) for the preparation of polyether polyols are sorbitol, sucrose, ethylenediamine, TDA, trimethylolpropane, pentaerythritol, glycerin, biodiesel, nonylphenol, ethylene glycol, and diethylene glycol. Further preferred starter molecules are all starters or starter mixtures with an average total functionality of ≦3, particularly preferred are glycerin, trimethylolpropane, biodiesel, nonylphenol, ethylene glycol, diethylene glycol, propylene glycol, and bisphenol A, especially preferred are ethylene glycol, diethylene glycol, and glycerin.

[0027] The polyether polyols used in the context of component (a1) advantageously have an average functionality of 1.5 to 6, in particular 2.0 to 4.0, and a number-average molecular weight of 150 to 3000, particularly preferably 150 to 1500, in particular 250 to 800 g / mol. The OH number of the polyether polyols of component (a1) is advantageously 1200 to 50, advantageously 600 to 100, in particular 300 to 150 mg KOH / g.

[0028] Suitable polyester polyols (a2) can be prepared from organic dicarboxylic acids having 2 to 12 carbon atoms, preferably aromatic dicarboxylic acids, or mixtures of aromatic and aliphatic dicarboxylic acids with polyhydric alcohols, preferably diols, having 2 to 12 carbon atoms, preferably 2 to 6 carbon atoms.

[0029] Dicarboxylic acids that come into consideration are, in particular, 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. Dicarboxylic acids can be used individually or in mixtures. Instead of free dicarboxylic acids, corresponding dicarboxylic acid derivatives, such as dicarboxylic acid esters of alcohols having 1 to 4 carbon atoms or dicarboxylic acid anhydrides, can also be used. As aromatic dicarboxylic acids or acid derivatives, phthalic acid, phthalic anhydride, terephthalic acid, and / or isophthalic acid are preferably used alone or in mixtures. As aliphatic dicarboxylic acids, dicarboxylic acid mixtures of succinic acid, glutaric acid, and adipic acid, for example, in a ratio of 20-35:35-50:20-32 parts by weight, especially adipic acid, are preferably used. Particularly preferably, polyesterols (a2) obtained exclusively from aromatic dicarboxylic acids or their derivatives are used. Preferably used as aromatic dicarboxylic acid is at least one compound selected from the group consisting of terephthalic acid, dimethyl terephthalate (DMT), polyethylene terephthalate (PET), phthalic acid, phthalic anhydride (PSA) and isophthalic acid, particularly preferably at least one compound selected from the group consisting of terephthalic acid, dimethyl terephthalate (DMT), polyethylene terephthalate (PET) and phthalic anhydride (PSA), in particular at least one compound from phthalic acid and / or phthalic anhydride.

[0030] Examples of dihydric and polyhydric alcohols, especially diols, are monoethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, 1,2- or 1,3-propanediol, dipropylene glycol, polypropylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, glycerin, trimethylolpropane, and pentaerythritol, as well as alkoxylates of the same starters. Advantageously, monoethylene glycol, diethylene glycol, triethylene glycol, 1,2- or 1,3-propanediol, dipropylene glycol, and ethoxylates of the same starters, such as ethoxylated glycerin, or mixtures of at least one of the aforementioned diols are used. In particular, monoethylene glycol, diethylene glycol, glycerin, and ethoxylates of the same starters, or mixtures of at least two of the aforementioned diols, particularly diethylene glycol, are used. Furthermore, polyester polyols from lactones, such as ε-caprolactone, or hydroxycarboxylic acids, such as ω-hydroxycaproic acid, can also be used.

[0031] To prepare the polyester polyols (a2), aliphatic and aromatic polycarboxylic acids and / or derivatives and polyhydric alcohols can be polycondensed without a catalyst or, preferably, in the presence of an esterification catalyst, suitably in an inert gas atmosphere such as nitrogen, in the melt at temperatures of 150 to 280°C, preferably 180 to 260°C, optionally under reduced pressure, until the desired acid number is reached, advantageously less than 10, preferably less than 2. Suitable esterification catalysts include, for example, iron, cadmium, cobalt, lead, zinc, antimony, magnesium, titanium, and tin catalysts in the form of metals, metal oxides, or metal salts. However, polycondensation can also be carried out in the liquid phase in the presence of diluents and / or azeotropic additives, such as benzene, toluene, xylene, or chlorobenzene, for azeotropic removal of condensed water.

[0032] To prepare the polyester polyols (a2), organic polycarboxylic acids and / or derivatives and polyhydric alcohols are polycondensed, preferably in a molar ratio of 1:1 to 2.2, advantageously 1:1.05 to 2.1, particularly preferably 1:1.1 to 2.0.

[0033] Generally, the polyester polyols (a2) obtained have a number average molecular weight of 200-3000, advantageously 300-1000, in particular 400-800.

[0034] Advantageously, the polyester polyol (a2) comprises at least one polyesterol (a2a), which is (a2a1) A dicarboxylic acid composition, (a2a11) 20 to 100 mol % of one or more aromatic dicarboxylic acids or derivatives thereof based on the dicarboxylic acid composition; (a2a12) 0 to 80 mol % of one or more aliphatic dicarboxylic acids or derivatives thereof based on the dicarboxylic acid composition 10 to 80 mol% of a dicarboxylic acid composition comprising: (a2a2) 0 to 30 mol% of one or more fatty acids and / or fatty acid derivatives; (a2a3) 2 to 70 mol % of one or more aliphatic or alicyclic diols having 2 to 18 C atoms or alkoxylates thereof, (a2a4) 0 to 80 mol % of an alkoxylation product of at least one starter molecule having an average functionality of at least 2, obtained by esterification of Each component is based on the total amount of components (a2a1) to (a2a4) in each case, and the sum of components (a2a1) to (a2a4) is 100 mol %.

[0035] Advantageously, the polyester polyols of component (a2) have a number-weighted average functionality of 1.7 or greater, preferably 1.8 or greater, particularly preferably 2.0 or greater, and especially greater than 2.2, which results in a high crosslink density in the polyurethanes produced therewith and thus improved mechanical properties of the polyurethane foams.

[0036] Furthermore, component (a) may contain a chain extender and / or a crosslinker, for example, to modify mechanical properties, such as hardness. Examples of chain extenders and / or crosslinkers include diols and / or triols, as well as amino alcohols having a molecular weight of less than 150 g / mol, preferably 60 to 130 g / mol. For example, aliphatic, cycloaliphatic, and / or araliphatic diols having 2 to 8, preferably 2 to 6, carbon atoms, such as ethylene glycol, 1,2-propylene glycol, diethylene glycol, dipropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, o-, m-, and p-dihydroxycyclohexane, and bis-(2-hydroxyethyl)hydroquinone, are also contemplated. Aliphatic and cycloaliphatic triols, such as glycerin, trimethylolpropane, and 1,2,4- and 1,3,5-trihydroxycyclohexane, are also contemplated.

[0037] If chain extenders, crosslinkers or mixtures thereof are used for the production of polyurethane rigid foams, they are suitably used in an amount of 0 to 15% by weight, preferably 0 to 5% by weight, based on the total weight of component (a). Advantageously, component (a) comprises less than 10% by weight, particularly preferably less than 7% by weight, and in particular less than 5% by weight, of chain extenders and / or crosslinkers.

[0038] As catalysts (b) for the production of polyurethane foams, in particular compounds are used which significantly accelerate the reaction of compounds of component (a) containing reactive hydrogen atoms, in particular hydroxyl groups, with polyisocyanates.

[0039] Suitably, basic polyurethane catalysts, for example tertiary amines such as triethylamine, tributylamine, dimethylbenzylamine, dicyclohexylmethylamine, dimethylcyclohexylamine, N,N,N',N'-tetramethyldiaminodiethyl ether, bis-(dimethylaminopropyl)urea, N-methyl or N-ethylmorpholine, N-cyclohexylmorpholine, N,N,N',N'-tetramethylethylenediamine, N,N,N,N-tetramethylbutanediamine, N,N,N,N-tetramethylhexanediamine-1,6, pentamethyldiethylenetriamine, bis(2-dimethylaminoethyl)ether, dimethylpiperazine , N-dimethylaminoethylpiperidine, 1,2-dimethylimidazole, 1-azabicyclo(2.2.0)octane, 1,4-diazabicyclo(2.2.2)octane (Dabco), and alkanolamine compounds such as triethanolamine, triisopropanolamine, N-methyl- and N-ethyldiethanolamine, dimethylaminoethanol, 2-(N,N-dimethylaminoethoxy)ethanol, N,N',N''-tris(dialkylaminoalkyl)hexahydrotriazines such as N,N',N''-tris(dimethylaminopropyl)-s-hexahydrotriazine, and triethylenediamine are used. However, metal salts such as iron(II) chloride, zinc chloride, lead octoate, and tin salts such as tin dioctoate, tin diethylhexanoate, and dibutyltin dilaurate, as well as mixtures of tertiary amines and organic tin salts, are also suitable.

[0040] Furthermore, suitable catalysts include amidines such as 2,3-dimethyl-3,4,5,6-tetrahydropyrimidine, tetraalkylammonium hydroxides such as tetramethylammonium hydroxide, alkali metal hydroxides such as sodium hydroxide, and alkali metal alcoholates such as sodium methylate and potassium isopropylate, alkali metal carboxylates and alkali metal salts of long-chain fatty acids having 8 to 20 carbon atoms and optionally a side OH group.

[0041] Furthermore, amines that can be incorporated as catalysts are considered, i.e., advantageously amines having OH, NH, NH2 functional groups, such as, for example, ethylenediamine, triethanolamine, diethanolamine, ethanolamine and dimethylethanolamine. The catalysts that can be incorporated can be considered as compounds of both component (b) and component (a).

[0042] Additionally, catalysts for the trimerization reaction of excess NCO groups may be catalysts for the formation of isocyanurate groups, such as ammonium ion salts or alkali metal salts, particularly ammonium carboxylates or alkali metal carboxylates, either alone or in combination with tertiary amines. The formation of isocyanurates results in the production of flame-retardant PIR foams, which are preferably used in industrial rigid foams, for example as insulation panels or sandwich elements in the building industry.

[0043] According to the present invention, catalyst (b) comprises at least one polyurethane catalyst (b1) containing at least one tertiary nitrogen atom, which is part of an aliphatic or aromatic ring and / or is bonded to at least one secondary carbon atom. Furthermore, catalyst (b) comprises at least one polyurethane catalyst (b2) selected from the group consisting of cyclic amides. It is essential to the present invention that polyurethane catalysts (b1) and (b2) do not have a dimethylamino group bonded to a primary carbon atom. In the context of the present invention, a primary carbon atom is understood to mean one directly bonded to only one additional carbon atom, a secondary carbon atom is understood to mean one directly bonded to exactly two additional carbon atoms, and a tertiary carbon atom is understood to mean one directly bonded to exactly three additional carbon atoms.

[0044] The polyurethane catalyst (b1) advantageously has at least one tertiary nitrogen atom directly bonded to at least one cycloaliphatic or aromatic hydrocarbon, a preferred example being N,N-dimethylcyclohexylamine. In a preferred embodiment, the catalyst (b1) comprises N,N-dimethylcyclohexylamine, and particularly preferably, the catalyst (b1) consists of N,N-dimethylcyclohexylamine.

[0045] The cyclic amide (b2) can be a lactam. In the context of the present invention, lactam is understood to mean an optionally substituted cyclic amide. The amide bond is located in the ring, and preferably there is only one amide group in the ring. Examples of lactams according to the present invention are β-propiolactam, 2-pyrrolidone, N-methylpyrrolidone, γ-butyrolactam, δ-valerolactam (2-piperidone) and ε-lactam (ε-caprolactam).

[0046] Advantageously, the cyclic amide is selected from the group consisting of at least one lactam, such as caprolactam and / or valerolactam, at least one cyclic urea or mixtures thereof, and particularly preferably, catalyst (b2) consists of caprolactam and / or valerolactam.

[0047] In a particularly preferred embodiment, the cyclic amide (b2) is represented by the general formula 2: [ka] wherein -X- is an optionally substituted 1- to 6-membered, advantageously 2- to 4-membered, particularly preferably 3-membered group. This results in a cyclic urea structure according to formula 2, the ring of which has 4 to 9, especially 6, members, including the urea structure -NH-C(O)-NR-. Advantageously, the constituents of the group X are -NR 1 -, -O-, -CR 2 R 3 -, -N= and -CR 4 The group -CR is selected from the group consisting of: 4In the case of = or -N=, the adjacent component is also -CR 4 = or -N= moieties, so that a double bond can be formed between the two moieties. 1 ~R 4 are, in each case, independently of one another, hydrogen, an alkyl group, advantageously ethyl or methyl, or a halogen, such as a fluoride or chloride group. In a highly preferred embodiment, X represents -(CH2)3-. The group R according to formula 2 represents a substituted or unsubstituted alkyl or heteroalkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted alkyl-aryl or heteroalkyl-aryl group. Substituents that come into consideration include, for example, a halide group, an alkyl group, a hydroxyl group, or an amine group. In a preferred embodiment of the present invention, R contains at least one isocyanate-reactive hydrogen atom, such as an -OH or -NH2 group. Advantageously, R represents methyl, ethyl, propyl, pentyl, hexyl, one or more alkylene oxide units, such as oxyethylene, oxypropylene, or a mixture of oxyethylene and oxypropylene, and phenyl, or phenyl ether. Particularly preferably, R represents -methyl, ethyl, oxyethylene, oxypropylene, or phenyl methoxy ester, and very preferably represents methyl. Similarly, a bridged cyclic urea structure in which two cyclic urea structures are bridged via a group R can also be used as the cyclic urea compound.

[0048] In one embodiment, R has a reactive group selected from an isocyanate-reactive group, advantageously a terminal —OH or NH group. In a further especially preferred embodiment, it is unsubstituted.

[0049] Highly preferably, R represents a linear unsubstituted hydrocarbon group selected from methyl, ethyl, propyl, pentyl and hexyl, and in particular R represents a methyl group.

[0050] The cyclic urea structure according to Formula 2 is known and has already been described many times, for example, in US Patent Publication No. 2013281451. Synthesis can be carried out, for example, starting from an N-halogenalkyl-3-alkylurea, such as 1-(2-chloroethyl)-3-methylurea. These urea compounds are cyclized in the presence of sodium hydride. This synthesis is also described in US Patent Publication No. 2013281451. Alternatively, synthesis can be carried out starting from urea and diamine, for example, as described in EP Patent Publication No. 976796, or by the reaction of dialkyl carbonate with diamine, for example, as described in EP Patent Publication No. 2548869.

[0051] Advantageously, 0.001 to 10 parts by weight, particularly preferably 0.1 to 8 parts by weight, in particular 0.5 to 5 parts by weight of the catalyst combination are used, based on 100 parts by weight of component (a). Advantageously, the catalyst does not contain metal catalysts and alkali metal carboxylates. Particularly preferably, the proportion of catalysts (b1) and (b2), based on the total weight of catalyst (b), is at least 80% by weight, particularly preferably at least 90% by weight, more preferably at least 95% by weight, and in particular, no further amine catalysts are contained in addition to catalysts (b1) and (b2).

[0052] The blowing agent (c) according to the present invention comprises at least one aliphatic halogenated hydrocarbon compound (c11) of the general formula (1) [ka] [In the formula, the group R 1 ~R 4 represent, in each case independently of one another, a hydrogen group, a fluoride group, a chloride group, a methyl group or an ethyl group, the hydrogen atoms of the methyl or ethyl groups being completely or partially substituted by chloride or fluoride, with the proviso that the compound according to formula (1) consists of 2 to 5 carbon atoms, at least one hydrogen atom and at least two halogen atoms selected from fluorine and chlorine atoms, and the group R 1and R 4 and at least one of the groups R 2 and R 3 at least one of which has at least one halogen atom, and the carbon atom of the carbon-carbon double bond having the methyl group or ethyl group further has a hydrogen atom.

[0053] Suitable compounds (c1) include trifluoropropenes and tetrafluoropropenes, such as (HFO-1234), pentafluoropropenes, such as (HFO-1225), chlorotrifluoropropenes, such as (HFO-1233), chlorodifluoropropenes and chlorotetrafluoropropenes, as well as mixtures of one or more of these components. Particularly preferred are tetrafluoropropenes, pentafluoropropenes and chlorotrifluoropropenes whose terminal unsaturated carbon atoms have more than one chlorine or fluorine substituent. Examples are 1,3,3,3-tetrafluoropropene (HFO-1234ze); 1,1,3,3-tetrafluoropropene, 1,2,3,3,3-pentafluoropropene (HFO-1225ye); 1,1,1-trifluoropropene; 1,1,1,3,3-pentafluoropropene (HFO-1225zc); 1,1,1,3,3,3-hexafluorobut-2-ene, 1,1,2,3,3-pentafluoropropene (HFO-1225yc); 1,1,1,2,3-pentafluoropropene (HFO-1225yez); 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd); 1,1,1,4,4,4-hexafluorobut-2-ene, or a mixture of two or more of these components.

[0054] Particularly preferably, the aliphatic halogenated hydrocarbon compound of general formula (1) has 3 carbon atoms and at least 4 halogen atoms. Examples of such particularly preferred compounds (c1) are hydroolefins selected from the group consisting of trans-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(E)), cis-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(Z)), trans-1,3,3,3-tetrafluoroprop-1-ene (HFO-1234ze(E)), cis-1,3,3,3-tetrafluoroprop-1-ene (HFO-1234ze(Z)), or a mixture of one or more of these components, in particular HFO 1233zd(E), 1234ze(E), or a mixture thereof.

[0055] Furthermore, blowing agents used to produce polyurethane foams according to the present invention preferably include water, formic acid, and mixtures thereof. These react with isocyanate groups to form carbon dioxide, or in the case of formic acid, carbon dioxide and carbon monoxide. These blowing agents are called chemical blowing agents because they release gas by chemical reaction with the isocyanate groups. In addition, physical blowing agents, such as low-boiling hydrocarbons, can also be used. Particularly suitable are liquids that are inert to the isocyanates used and have a boiling point below 100°C, preferably below 50°C at atmospheric pressure, and therefore evaporate under the influence of the exothermic polyaddition reaction. Examples of such liquids that are advantageously used are aliphatic or cycloaliphatic hydrocarbons having 4 to 8 carbon atoms, such as heptane, hexane, and isopentane, preferably n-pentane and isopentane, technical mixtures of n-butane and isobutane with propane, cycloalkanes such as cyclopentane and / or cyclohexane, ethers such as furan, dimethyl ether, and diethyl ether, ketones such as acetone and methyl ethyl ketone, alkyl carboxylic acid esters such as methyl formate, dimethyl oxalate, and ethyl acetate, and halogenated hydrocarbons such as methylene chloride, dichlorofluoromethane, difluoromethane, trifluoromethane, difluoroethane, tetrafluoroethane, chlorodifluoroethane, 1,1-dichloro-2,2,2-trifluoroethane, 2,2-dichloro-2-fluoroethane, and heptafluoropropane. Mixtures of these low-boiling liquids with each other and / or with other substituted or unsubstituted hydrocarbons can also be used.

[0056] In the context of the present invention, physical blowing agents that do not fall within the definition of (c1) are called physical blowing agents (c2), and chemical blowing agents are called chemical blowing agents (c3).

[0057] Furthermore, suitable chemical blowing agents (c3) are organic carboxylic acids, such as acetic acid, oxalic acid, ricinoleic acid, and carboxyl-containing compounds. Advantageously, halogenated hydrocarbons are not used as blowing agents in addition to compound (c1). Advantageously, water, formic acid-water mixtures, or formic acid are used as chemical blowing agents (c3), with water or formic acid-water mixtures being particularly preferred.

[0058] Preferably, in addition to component (c1), at least one chemical blowing agent (c3) is used.

[0059] The amount of blowing agent or blowing agent mixture used is generally 1 to 30% by weight, advantageously 1.5 to 20% by weight, particularly preferably 2.0 to 15% by weight, in each case based on the sum of components (a) to (d). If water or a formic acid-water mixture is used as blowing agent, it is advantageously added to the polyol component in an amount of 0.2 to 6% by weight, particularly preferably 1 to 4% by weight, based on the total weight of the polyol component.

[0060] Examples of auxiliary and / or additive (d) that can be used include surface-active substances, foam stabilizers, cell regulators, external and internal mold release agents, fillers, pigments, dyes, flame retardants, antistatic agents, aromatic amine reducing substances, such as lactams, hydrolysis inhibitors, and fungistatic and bacteriostatic active substances. In particular, the use of lactams, such as ε-caprolactam, together with the cyclic ureas of formula 2 according to the present invention leads to a reduction of aromatic amines in the polyurethane.

[0061] Further information on the starting materials used can be found, for example, in Kunststoffhandbuch, Band 7, Polyurethane, edited by Güenter Oertel, Carl-Hanser-Verlag, München, 3. Auflage 1993, Kapitel 5, Polyurethanweichschaumstoffe.

[0062] The present invention further relates to a method for producing polyurethane foam, comprising mixing a polyol component according to the present invention with an isocyanate component containing at least one polyisocyanate to form a reaction mixture and converting the mixture into polyurethane foam. According to the present invention, polyurethane foam is produced by mixing a polyol component with an isocyanate component containing a polyisocyanate to form a reaction mixture and reacting the reaction mixture to form polyurethane foam. In the context of the present invention, the reaction mixture refers to a mixture of an isocyanate and an isocyanate-reactive compound (a) having a reaction conversion of less than 90% based on the isocyanate groups. Advantageously, a two-component process is used in which all starting materials are included in either the isocyanate component or the polyol component. Advantageously, all materials capable of reacting with isocyanates are added to the polyol component, while starting materials that are not isocyanate-reactive can be added to either the isocyanate component or the polyol component. Advantageously, the isocyanate component contains only isocyanates.

[0063] Generally, the equivalent ratio of NCO groups to the sum of reactive hydrogen atoms of the polyisocyanate is 0.75 to 1.5:1, preferably 0.80 to 1.25:1. If the polyurethane contains at least some isocyanurate groups, the polyisocyanate (a) is usually used in a ratio of NCO groups to the sum of reactive hydrogen atoms of 1.5 to 20:1, preferably 1.5 to 8:1. A ratio of 1:1 corresponds to an isocyanate index of 100. If polyurethane flexible foams are to be produced, the mixing ratio is chosen so that the isocyanate index is advantageously 50 to 95, particularly preferably 60 to 80, and in particular 65 to 75.

[0064] The polyurethanes of the present invention are preferably produced according to a one-shot process, for example, using high-pressure or low-pressure techniques. The polyurethanes of the present invention are produced, for example, on a belt or, preferably, in a mold. Molded polyurethane foams can be produced, for example, in open or closed metal molds.

[0065] The polyol component and the polyisocyanate component are preferably mixed at a temperature in the range of 15 to 120°C, preferably 20 to 80°C, and brought into a mold or on a conveyor line. The temperature in the mold is usually in the range of 15 to 120°C, preferably 30 to 80°C.

[0066] The polyisocyanates used to prepare the polyurethanes according to the invention include all polyisocyanates known for the preparation of polyurethanes. These include aliphatic, cycloaliphatic, and aromatic di- or polyisocyanates known from the prior art, as well as any mixtures thereof. Examples include 2,2'-, 2,4'-, and 4,4'-diphenylmethane diisocyanate, mixtures of monomeric and higher-nuclear homologues of diphenylmethane diisocyanate (polymeric MDI), isophorone diisocyanate (IPDI) or its oligomers, 2,4- or 2,6-toluylene diisocyanate (TDI) or mixtures thereof, tetramethylene diisocyanate or its oligomers, hexamethylene diisocyanate (HDI) or its oligomers, naphthylene diisocyanate (NDI) or mixtures thereof.

[0067] These advantageously include toluene diisocyanate isomers (TDI isomers) and isomers of methylene diphenyl diisocyanate and their higher nuclear homologues (MDI). Particularly preferred aromatic polyisocyanates include mixtures containing 2,4'-MDI, 4,4'-MDI, and higher nuclear homologues of MDI (hereinafter referred to as "polymeric MDI" or "PMDI"). Furthermore, modified isocyanates can be used, for example, isocyanates in which polyisocyanates are formed by incorporating groups starting from isocyanate groups. Examples of such groups are allophanate groups, carbodiimide groups, uretonimine groups, isocyanurate groups, urea groups, and biuret groups. In a preferred embodiment, the proportion of 2,4'-diphenylmethane diisocyanate is advantageously 5 to 30% by weight, and the proportion of 4,4'-diphenylmethane diisocyanate is advantageously 40 to 80% by weight, in each case based on the total weight of aromatic polyisocyanate (a). In a preferred embodiment, the proportion of higher nuclear homologues of diphenylmethane diisocyanate is 3 to 30% by weight, particularly preferably 5 to 25% by weight.

[0068] The aromatic polyisocyanates can also be used in the form of prepolymers. For this purpose, the aromatic polyisocyanates are reacted in excess with compounds having isocyanate-reactive groups. The isocyanate-reactive groups are preferably those listed under (a) having at least two isocyanate-reactive hydrogen atoms. When isocyanate prepolymers are used as aromatic isocyanates, they preferably have an NCO content of 16 to 31% by weight.

[0069] Finally, the present invention encompasses polyurethane foams obtainable according to the process of the present invention. The density of such foams according to the present invention is advantageously between 10 and 150 g / L, particularly preferably between 15 and 100 g / L, more preferably between 20 and 70 g / L, and in particular between 25 and 60 g / L.

[0070] The polyol component according to the present invention is characterized by improved storage stability both at room temperature and at elevated temperatures, e.g., 70°C. In this case, inexpensive catalysts can be used, which achieve the reaction profile typically found in commercial systems. Thus, advantageously, the reaction mixture according to the present invention has an initiation time in the range of 10-20 seconds, a cure time of 50-80 seconds, and a tack-free time of 120-200 seconds.

[0071] In particular, when the isocyanate index is less than 100 and the water content is more than 1%, the method according to the invention can significantly reduce the concentration of aromatic amines, for example at the surface of polyurethane foam.

[0072] The present invention will now be more clearly illustrated by the following examples.

[0073] In the examples, the following materials were used: [Table 1]

[0074] The polyol components used in the systems are listed in Table 1, the amounts being expressed in parts by weight. System 1 is a reference system, while systems 2 to 4 are according to the invention. The aim is to achieve a longer storage stability compared to the reference systems by adapting the catalysis. To this end, the following work was carried out in the laboratory:

[0075] [Table 2]

[0076] In each case, 1000 g of polyol component batches consisting of polyol, stabilizer, catalyst, and blowing agent were mixed in a Vollrath laboratory mixer according to Table 1. 200 g of the mixture was then filled into 250 mL laboratory glasses, which were tightly capped. For each polyol component, two glasses were stored at 23°C and two glasses at 40°C. The remaining polyol components were used as they were for the tests.

[0077] This series of experiments aimed to investigate the effects of storage time and storage temperature. Series 2 to 5 were adjusted to have comparable cure times and densities to those of Series 1. This was done by adjusting the amount of catalyst. The laboratory values ​​on day 0 were used as initial values.

[0078] The test was carried out as follows: The polyol component listed in Table 1 and the isocyanate component consisting of Isocyanate 1 were heated to 20±1°C. The polyol component was placed in a paper cup, and the isocyanate component was added. The polyol component and isocyanate component were mixed in a 100:116 ratio. A Vollrath stirrer with a Lenart disc was used for mixing. The stirring speed was 1400 rpm. A stopwatch was started once stirring began. The foam set time, needle height, tack-free time, and foam density were subsequently measured. These values ​​for systems 1 to 5 are shown in Tables 2 to 6 both immediately after preparation of the polyol component and after storage for 28 and 71 days at 23 and 40°C, respectively.

[0079] [Table 3]

[0080] [Table 4]

[0081] [Table 5]

[0082] [Table 6]

[0083] [Table 7]

[0084] The setting time is defined as the time from the start of mixing until the foam mass becomes threadable with a rod during the reaction process. At the same time as the setting time is reached, a needle is pierced into the foam just above the rim of the cup. After the foam has finished expanding in volume, a ruler is used to measure the distance traveled by the needle. In addition, the tack-free time is also measured. This is defined as the time interval from the start of mixing until no adhesion is observed between the foam surface and the pipette when touching it with the pipette. After the foam has set, the crown of the foam is cut off above the rim of the cup. The contents of the cup are weighed and the density is measured.

[0085] The onset and rise times are determined by a foam qualification system, the Foamat measuring device from Format Messtechnik. The onset time is defined as the time from the start of stirring to the start of the volume expansion of the reaction mixture due to foam formation. The rise time is defined as the time from the start of stirring to the end of the volume expansion.

[0086] It is clear that the reaction parameters change only slightly after storage in the examples according to the present invention. In contrast, the reaction times, such as initiation time, cure time, rise time, and tack-free time, increase significantly in the comparative example according to system 1, and foams are no longer obtainable after 71 days of storage at 40°C. In contrast, the comparative example according to system 5, 2, shows a very slow initiation time and an undesirably large needle height. Therefore, the strong expansion of the foam after curing may lead to the destruction of the internal foam structure.

[0087] Figure 1 again clearly shows graphically the change in setting time based on storage time at 23°C and 40°C. [Brief explanation of the drawings]

[0088] [Figure 1] FIG. 1 clearly shows the change in setting time based on storage time at 23° C. and 40° C.

Claims

1. 1. A polyol component for producing a polyurethane foam, comprising: a) a compound having at least two isocyanate-reactive hydrogen atoms; b) a catalyst, b1) at least one polyurethane catalyst (b1) containing at least one tertiary nitrogen atom, said tertiary nitrogen atom being part of an aliphatic or aromatic ring and / or said tertiary nitrogen atom being bonded to at least one at least secondary carbon atom; and b2) at least one polyurethane catalyst selected from the group consisting of cyclic amides (b2) It encompasses The polyurethane catalysts (b1) and (b2) do not have a dimethylamino group bonded to a primary carbon atom. A catalyst; c) at least one aliphatic halogenated hydrocarbon compound (c11) of general formula (1) 【Chemistry 1】 [In the formula, the group R １ ~R ４ represent, in each case independently of one another, a hydrogen group, a fluoride group, a chloride group, a methyl group or an ethyl group, the hydrogen atoms of which may be completely or partially substituted by chloride or fluoride, with the proviso that the compound according to formula (1) consists of 2 to 5 carbon atoms, at least one hydrogen atom and at least two halogen atoms selected from fluorine and chlorine atoms, and the group R １ and R ４ and at least one of the groups R ２ and R ３ at least one of them has at least one halogen atom, and the carbon atom of the carbon-carbon double bond having the methyl group or ethyl group further has a hydrogen atom. A blowing agent comprising at least one physical blowing agent (c1) comprising: d) optionally additives; A polyol component comprising:

2. 2. The polyol component of claim 1, wherein said aliphatic halogenated hydrocarbon compound of general formula (1) has 3 carbon atoms and at least 4 halogen atoms.

3. 3. The polyol component according to claim 1 or 2, wherein the aliphatic halogenated hydrocarbon compound of general formula (1) is HFO 1233zd(E) or 1234ze(E).

4. 4. The polyol component according to claim 1, wherein the polyurethane catalyst (b1) has at least one tertiary nitrogen atom directly bonded to at least one cycloaliphatic or aromatic hydrocarbon.

5. The polyol component of claim 4, wherein the polyurethane catalyst (b1) comprises N,N-dimethylcyclohexylamine.

6. 6. The polyol component according to claim 1, wherein the cyclic amide (b2) is selected from the group consisting of caprolactam, valerolactam or at least one cyclic urea.

7. 7. The polyol component according to claim 1, wherein the cyclic amide (b2) is ε-caprolactam and / or valerolactam.

8. The cyclic amide (b2) is represented by the general formula 2: 【Chemistry 2】 wherein -X- represents a substituted or unsubstituted 1- to 6-membered group, and R represents a group selected from a substituted or unsubstituted alkyl or heteroalkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted alkyl-aryl or heteroalkyl-aryl group.

7. The polyol component according to claim 1, wherein the polyol component is a cyclic urea of ​​the formula:

9. X is -(CH ２ ) ３ The polyol component according to claim 8, characterized in that it represents -.

10. R is an —OH group or —NH ２ The polyol component according to claim 8 or 9, characterized in that it has a group.

11. 11. The polyol component according to claim 1, wherein in addition to the catalysts (b1) and (b2), no further amine catalysts are contained.

12. The polyol component according to any one of claims 1 to 11, characterized in that it comprises water.

13. 13. A method for producing a polyurethane foam, comprising combining the polyol component of any one of claims 1 to 12 with an isocyanate component comprising at least one polyisocyanate to form a reaction mixture and converting the resulting mixture into a polyurethane foam.

14. A polyurethane foam obtainable by the method of claim 13.

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