PROCESS FOR PRODUCING POLYOXYALKYLENE POLYESTER POLYOLS

Description

[0001] The present invention relates to a process for producing polyoxyalkylene polyester polyols with calculated OH numbers of 320 mg (KOH) / g to 530 mg (KOH) / g by reacting a starter compound containing alcoholic hydroxyl groups and / or aminic protons and a fatty acid ester with an alkylene oxide. Further subjects of the invention are polyoxyalkylene polyester polyols resulting from the process and a production process for polyurethanes by reacting the polyoxyalkylene polyester polyols of the invention with polyisocyanates.

[0002] Polyols based on renewable raw materials such as fatty acid triglycerides, sugar, sorbitol, glycerol, and dimer fatty alcohols are already used in a variety of ways as raw materials in the production of polyurethane materials. The use of such components will continue to increase in the future, as products from renewable sources are rated favorably in life cycle assessments and the availability of petrochemical-based raw materials will decrease in the long term. Through the targeted use of fatty acid esters in the production of alkylene oxide addition products based on starters with Zerewitinoff-active hydrogen atoms, polyetherester polyols can also be obtained. These polyols are characterized by improved solubility for blowing agents based on (partially halogenated) hydrocarbons typically used in rigid foam formulations, or generally by increased hydrophilicity of the materials produced from them.

[0003] EP 1923417 A1 discloses a one-step process for the production of polyetherester polyols by reacting starter compounds containing Zerewitinoff-active hydrogen atoms ("H-functional starter compounds") with alkylene oxides under base catalysis in the presence of fatty acid esters as a renewable raw material. The fatty acid residues of the fatty acid esters do not contain any free OH groups. These polyetherester polyols are used as components in formulations with other polyols in the production of PUR / PIR rigid foams. These PUR / PIR systems are characterized by good demolding behavior.

[0004] WO 2013 / 016263 A2 describes a process for producing amine-initiated polyether polyols, partially using renewable raw materials, as well as the use of such polyether polyols in the production of rigid polyurethane foams. The process comprises reacting an amine-based alkoxylation adduct with a triglyceride and optionally a polysaccharide, both of which originate from renewable sources.

[0005] EP 2177555 A2 relates to a process for producing polyetherester polyols starting from fatty acid esters and starter compounds with Zerewitinoff-active hydrogen atoms, and their use for producing solid or foamed polyurethane materials. The process ensures smooth uptake of the metered alkylene oxides, allowing them to be added continuously. This process is particularly suitable for producing polyetherester polyols based on starter compounds with a melting point close to or above the usual reaction temperature, i.e., with a melting point above 100°C, or for producing polyetherester polyols based on starter compounds that tend to decompose at the usual reaction temperature.

[0006] EP 2807199 A1 discloses a process for producing a polyoxyalkylene polyetherester polyol by reacting a Zerwitinoff-active starter compound with fatty acid esters and alkylene oxides using basic imidazole catalysts. The production is additionally carried out in the presence of a cyclic anhydride of dicarboxylic acids. The resulting polyetherester polyols are also used in the production of rigid foams. It is assumed that the presence of the aromatic dicarboxylic acid units in the final polyoxyalkylene polyester polyol product leads to improved flame-retardant properties.

[0007] WO 2021 / 122401 A1 discloses a process for preparing polyoxyalkylene polyester polyols by reacting a starter compound containing Zerewitnoff-active H atoms, a cyclic dicarboxylic acid anhydride and a fatty acid ester with an alkylene oxide in the presence of a basic catalyst, resulting in less discolored products.

[0008] However, the processes proposed in the prior art prove problematic when highly hydrophobic polyoxyalkylene polyester polyols based on starter compounds that are solid at room temperature and based on fatty acid esters with maximum OH numbers of 100 mg (KOH) / g are to be produced, especially those polyoxyalkylene polyester polyols with a fatty acid ester content of 40 mass % or more. It turns out that cloudy or even multiphase end products often result, even when the process proposed in EP 2177555 A2 is used.

[0009] Surprisingly, the object was achieved by a process for producing a polyoxyalkylene polyester polyol having a calculated OH number of 320 mg KOH / g to 530 mg KOH / g, preferably of 350 mg KOH / g to 500 mg KOH / g, by reacting an H-functional starter compound (1) having n(1) mol of alcoholic hydroxyl groups and / or aminic protons, preferably having n(1) mol of alcoholic hydroxyl groups, and a fatty acid ester (2) having n(2) mol of fatty acid ester groups with an alkylene oxide (3), optionally in the presence of a basic catalyst (4) and optionally in a solvent (5), wherein the H-functional starter compound (1) comprises one or more compounds, wherein at least one H-functional starter compound (1) has a melting point of > 50.0 °C, preferably > 55.0 °C, wherein the fatty acid ester (2) has an OH number of less than 100 mg KOH / g,wherein the proportion of the fatty acid ester (2) is at least 40% by mass, based on the total mass of the H-functional starter compound (1), the fatty acid ester (2) and the alkylene oxide (3) used, the process comprising the following steps: (i) Providing a system (i) comprising the H-functional starter compound (1) optionally the basic catalyst (4) optionally in a solvent (5) in a reaction vessel, (ii) Adding n(3-1) mol of a first portion of the alkylene oxide (3) to the system (i) over a period t 1 to form an intermediate (ii), (iii) Removing any solvent (5) present from the intermediate (ii) to form an intermediate (iii), (iv) Adding the fatty acid ester (2) to the intermediate (ii) or to the intermediate (iii) to form the intermediate (iv), wherein n(2) mol of fatty acid ester groups are added to the intermediate (ii) or the intermediate (iii), (v) Adding n(3-2) mol of a second portion of the alkylene oxide (3) to the intermediate (iv) over a period t 2 to form the polyoxyalkylene polyester polyol, where (n(3-2) / n(2)) • t 2 / [h] ≥ 1.0; preferably 1.0 ≤ (n(3-2) / n(2)) • t 2 / [h] ≤ 10.0; particularly preferably 1.0 ≤ (n(3-2) / n(2)) • t 2 / [h] ≤ 8.0, where n(2) / n(3-2) ≥ 1.05; preferably 1.05 ≤ n(2) / n(3-2) ≤ 10.0; particularly preferably 1.25 ≤ n(2) / n(3-2) ≤ 6, and where n(3-1) / n(1) ≥ 0.43; preferably 0.43 ≤ n(3-1) / n(1) ≤ 0.92, particularly preferably 0.44 ≤ n(3-1) / n(1) ≤ 0.80.

[0010] The expression "t 2 / [h]" denotes the numerical value of the period t 2 specified in hours.

[0011] In the context of the present invention, Polyoxyalkylene polyester polyolsare to be understood as products of the reaction of starter compounds (1), fatty acid esters (2), and alkylene oxides (3), whereby ester units are obtained by the reaction of the fatty acid esters (2), and the ring-opening products of the alkylene oxides (3) can also lead to ether bonds. In such a process, polyoxyalkylene polyester polyols with hydroxyl end groups are formed from the starter compound (1) with n(1) mol of alcoholic hydroxyl groups and / or aminic protons, preferably with n(1) mol of alcoholic hydroxyl groups.

[0012] Under aminic protons are understood to mean protons of ammonia, primary, and secondary amines, where a primary amine with an NH 2 group provides two aminic protons, resulting in two alcoholic hydroxy groups by addition of alkylene oxides according to common technical knowledge. Analogously, a secondary amine provides one aminic proton and ammonia three aminic protons.

[0013] According to the invention, alcoholic hydroxy groups Hydroxy groups of an alcohol of the formula R-OH, where R is an alkyl, aryl, or cycloalkyl group and R is not H (hydrogen). The alcoholic hydroxy group provides an alcoholic proton, which in turn results in an alcoholic hydroxy group by addition of alkylene oxides according to common technical knowledge. The number of n(1) mol of alcoholic hydroxy groups introduced by the starter compound is calculated as follows: n 1 = ∑ i = 1 i = n n i × F i with: ni = number of moles of starter component i used F i = hydroxy functionality of starter component i

[0014] The number of n(1) mol of alcoholic hydroxy groups resulting from aminic starter compounds is calculated as follows: n 1 = ∑ j = 1 j = n n j × F j with: nj = number of moles of the aminic starter component j used F j = number of aminic protons introduced by the aminic starter component j per molecule

[0015] The OH number of the polyoxyalkylene polyester polyol according to the invention is calculated as follows (OH number calc.). The OHN is given in mg KOH / g OHZ ber = ∑ i mi i × OHZ i + ∑ j m j × OHZ j + ∑ f m f × OHZ f Ansatzmasse with: Batch mass = sum of the masses of all added components less the mass of any solvent separated in step (iii) mi = mass of the hydroxy-functional starter component i mj = mass of the amine-functional starter component jmf = mass of the fatty acid ester f OH number i = OH number of the starter component i OH number j = effective OH number of the amine starter component j OH number f = OH number of the fatty acid ester f

[0016] The OH numbers of hydroxy-functional starter components (OHN i ) or the OH numbers of the fatty acid esters (OHN f ) can be calculated using the following formulas, provided that the molecular weights M i and the hydroxy functionalities F i of the starter components or the molecular weights M f and the hydroxy functionalities F f of the fatty acid esters are known: OHZ i = 56100 × F i M i OHZ f = 56100 × F f M f

[0017] Accordingly, the effective OH number (OHN j ) for aminic starter compounds can be calculated using the following formula if the number F j of aminic protons introduced per molecule of the aminic starter compound j and the molar mass M j of the aminic starter compound j are known: OHZ j = 56100 × F j M j

[0018] If M i , F i , M f and / or F f are not known, which is likely to be the case in particular for F f and M f, the corresponding OH numbers OHZ i and OHZ f can also be determined using titrimetric methods, for example in accordance with the DIN 53240 regulations.

[0019] Embodiments of the invention are disclosed below, which can be combined with one another as desired, as long as the technical context does not indicate otherwise.

[0020] Under H-functional starter compounds (1)For the purposes of the invention, compounds are understood to be those which have at least one alcoholic hydroxyl group and / or at least one aminic proton, preferably at least one alcoholic hydroxyl group.

[0021] According to the invention, the H-functional starter compound (1) comprises one or more compounds, wherein at least one (first) H-functional starter compound (1) has a melting point of > 50.0 °C, preferably > 55.0 °C, determined according to the method DIN EN ISO 11357-1:2016.

[0022] Suitable H-functional starter compounds ("starters") preferably have functionalities of 2 to 8, but in certain cases also functionalities up to 35. Their molar masses range from 17 g / mol to 1,200 g / mol.

[0023] In one embodiment of the process according to the invention, the (first) starter compound (1) has a melting point of more than 65 °C, preferably from 65 °C to 265 °C and particularly preferably from 80 °C to 180 °C.

[0024] In a preferred embodiment of the process according to the invention, the (first) H-functional starter compound (1) with a melting point of > 50.0 °C is one or more compounds and is selected from the group consisting of trimethylolpropane, pentaerythritol, sorbitol, sucrose, hydroquinone, pyrocatechol, resorcinol, bisphenol F, bisphenol A, 1,3,5-trihydroxybenzene, 1,12-dodecanediol, the isomers of diaminotoluene, the isomers of diaminodiphenylmethane, preferably from the group consisting of pentaerythritol, sorbitol and sucrose.

[0025] The (first) H-functional starter compound (1) with a melting point of > 50.0 °C is used either individually or as a mixture of at least two (first) H-functional starter compounds (1).

[0026] In one embodiment of the process according to the invention, the H-functional starter compound (1) also comprises at least one second H-functional starter compound having a melting point of ≤ 50 °C.

[0027] In a preferred embodiment of the process according to the invention, the second H-functional starter compound with a melting point of ≤ 50 °C is one or more compounds and is selected from the group consisting of propylene glycol, ethylene glycol, diethylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, hexanediol, pentanediol, 3-methyl-1,5-pentanediol, glycerol, triethanolamine, ammonia, ethanolamine, diethanolamine, isopropanolamine, diisopropanolamine, ethylenediamine, hexamethylenediamine, aniline and the isomers of toluidine, preferably from propylene glycol, ethylene glycol and glycerol.

[0028] The (second) H-functional starter compound (1) with a melting point of ≤ 50 °C is used either individually or as a mixture of at least two (second) H-functional starter compounds (1).

[0029] In one embodiment of the process according to the invention, the mass ratio of the second H-functional starter compound used with a melting point <50°C to the first H-functional starter compound used with a melting point of ≥ 50°C is from 0.1:1 to 0.5:1, preferably from 0.2:1 to 0.4:1.

[0030] The generic term "fatty acid esters" refers below to fatty acid glycerides, in particular fatty acid triglycerides, and / or fatty acid esters based on other mono- and polyfunctional alcohols, or mixtures of such fatty acid esters or fatty acid glycerides. The fatty acid residues of the fatty acid esters can, as in castor oil, themselves carry hydroxyl groups. Of course, it is also possible to use fatty acid esters whose fatty acid residues have been subsequently modified with hydroxyl groups in the process according to the invention. Such modified fatty acid residues can be obtained, for example, by epoxidation of the olefinic double bonds and subsequent ring opening of the oxirane rings using nucleophiles or by hydroformylation / hydrogenation. Unsaturated oils are also frequently treated with atmospheric oxygen at elevated temperatures for this purpose.

[0031] All triglycerides are suitable as substrates for the processes according to the invention. Examples include cottonseed oil, peanut oil, coconut oil, linseed oil, palm kernel oil, olive oil, corn oil, palm oil, castor oil, lesquerella oil, rapeseed oil, soybean oil, sunflower oil, herring oil, sardine oil, and tallow. Fatty acid (tri)glycerides and the fatty acid esters of other mono- and polyfunctional alcohols can also be used in mixtures. The OH number of such a fatty acid ester or fatty acid ester mixture is a maximum of 100 mg (KOH) / g.

[0032] In one embodiment of the process according to the invention, the fatty acid ester (2) has no free hydroxyl groups in the fatty acid residues.

[0033] In one embodiment of the process according to the invention, the fatty acid ester (2) is one or more compounds and is selected from the group consisting of cottonseed oil, peanut oil, coconut oil, linseed oil, palm kernel oil, olive oil, corn oil, palm oil, jatropha oil, rapeseed oil, soybean oil, sunflower oil, herring oil, sardine oil and tallow, preferably soybean oil.

[0034] The fatty acid esters (2) are used either individually or as a mixture of at least two fatty acid esters.

[0035] According to the invention, the proportion of the fatty acid ester (2) is at least 40% by mass based on the total mass of the H-functional starter compound (1) used, the fatty acid ester (2) used and the alkylene oxide (3) used.

[0036] In a preferred embodiment of the process according to the invention, the proportion of the fatty acid ester (2) is from 40 mass% to 60 mass%, preferably from 42 mass% to 58 mass%, and particularly preferably from 45 mass% to 55 mass%, based on the total mass of the H-functional starter compound (1) used, the fatty acid ester (2) used and the alkylene oxide (3) used.

[0037] Suitable alkylene oxides (3) are, for example, ethylene oxide, propylene oxide, 1,2-butylene oxide or 2,3-butylene oxide, and styrene oxide. Propylene oxide and ethylene oxide are preferably added to the reaction mixture individually, as a mixture, or successively. If the alkylene oxides are added successively, the products prepared contain polyether chains with block structures. For example, a different alkylene oxide can be added in step (v) than in step (ii). Products with ethylene oxide end blocks are generally characterized by increased concentrations of primary end groups, which impart a possibly required higher isocyanate reactivity to the systems. Preferred alkylene oxides are propylene oxide and / or ethylene oxide; propylene oxide is particularly preferred.

[0038] In one embodiment of the process according to the invention, the alkylene oxide (3) is propylene oxide and / or ethylene oxide, preferably propylene oxide.

[0039] The alkylene oxides (3) are used either individually or as a mixture of at least two alkylene oxides. Basic catalyst (4)

[0040] In one embodiment of the process according to the invention, the basic catalyst (4) is added in step (i) and / or in step (iv). Preferably, the basic catalyst is added in step (i).

[0041] In one embodiment of the process according to the invention, an alkali metal or alkaline earth metal hydroxide, preferably potassium hydroxide, is used as the basic catalyst. The catalyst can be added to the reaction mixture in the form of aqueous solutions or in anhydrous form. Preferably, any water of solution present or water formed by the deprotonation of the OH groups is removed before the fatty acid esters are added to the reaction mixture. Dehydration can be carried out, for example, by annealing under reduced pressure at temperatures of 80 to 150°C and, if appropriate, assisted by stripping with an inert gas. The catalyst concentration is preferably 0.02 to 1% by mass, based on the amount of end product; more preferably, 0.05 to 0.6% by mass.

[0042] In a more preferred embodiment of the process according to the invention, the reaction in step (i) and / or in step (iv), preferably in step (i), takes place in the presence of a basic catalyst (4), wherein the basic catalyst is preferably an amine, preferably an aromatic amine.

[0043] In a particularly preferred embodiment of the process according to the invention, the amine is an aromatic amine and the aromatic amine is one or more compounds selected from the group consisting of imidazole, 1-methylimidazole, 2-methylimidazole, 4(5)-methylimidazole, 2,4(5)dimethylimidazole, 1-ethylimidazole, 2-ethylimidazole, 1-phenylimidazole, 2-phenylimidazole, 4(5)phenylimidazole, and N,N-dimethylaminopyridine.

[0044] A comprehensive overview of usable amines has been provided by M. Ionescu et al. in "Advances in Urethanes Science and Technology," 1998, 14, 151-218. The amine catalysts can be used in concentrations of 200 ppm to 10,000 ppm, based on the final product amount; the concentration range from 200 ppm to 5,000 ppm is preferred.

[0045] In a further, less preferred embodiment of the process according to the invention, carboxylic acid salts of alkali or alkaline earth metals are used as basic catalysts. The underlying carboxylic acids can be monobasic or polybasic. Examples are salts of acetic, propionic, and adipic acid. Such alkali or alkaline earth carboxylates are typically used in amounts of 0.04 to 2% by mass, based on the final product.

[0046] According to the invention, suitable solvents (5) or suspending agents are inert organic solvents such as, for example, toluene or water. In particular, the presence of water in step (ii) of the process according to the invention can promote the conversion of the at least one H-functional starter compound having a melting point > 50 °C with alkylene oxides. In order to obtain high-quality, i.e. low-by-product, alkylene oxide addition products, it is advisable to remove water from the reaction mixture after a certain degree of alkoxylation has been reached; see, for example, German Offenlegungsschrift DE 1443022. The removal of water in step (iii) of the process according to the invention should also take place before the addition of the fatty acid ester in step (iv) in order to avoid undesired hydrolysis reactions.

[0047] In one embodiment of the process according to the invention, in step i) the system (i) comprises a solvent (5), wherein the solvent (5) contains water and preferably the solvent (5) is water.

[0048] In a preferred embodiment of the process according to the invention, in step i) the system (i) comprises the H-functional starter compound (1), the basic catalyst (4) and the solvent (5), wherein the solvent (5) contains water and preferably the solvent (5) is water.

[0049] Steps (i), (ii), (iii), (iv) and (v) of the process according to the invention are carried out in detail as described below: In step (i) of the process according to the invention, a system (i) comprising the starter compound (1) and optionally the basic catalyst (4) optionally in a solvent (5) is provided in a reaction vessel.

[0050] According to the invention, the system (i) in step (i) also comprises the starter compound (1), the starter compound (1) and the basic catalyst (4) or the starter compound (1) and the solvent (5), insofar as only the starter compound (1), the starter compound (1) and the basic catalyst (4) or the starter compound (1) and the solvent (5) are used in step (i).

[0051] Preferably, the basic catalyst (4) and the solvent (5) are used in step (i), so that a system (i) comprising the starter compound (1) and the basic catalyst (4) with a solvent (5) is provided in a reaction vessel.

[0052] System (i) is prepared by stirring or pumping through a dispersing unit while inerting the reaction vessel (e.g., by repeatedly pressurizing with nitrogen, followed each time by depressurizing to atmospheric pressure, and if necessary, evacuating to pressures < 1 bar). To facilitate mixing / dispersion of the components, stirring or pumping can be performed at elevated temperature, for example, at 50 to 150 °C, and under an inert gas atmosphere (such as nitrogen). It is generally not necessary to adhere to a specific minimum stirring or pumping time.

[0053] In step (ii) of the process according to the invention, n(3-1) moles of a first portion of the alkylene oxide (3) are added to the system (i) over a period of time t 1 to form an intermediate (ii).

[0054] The addition of the first portion of the alkylene oxide (3) to the system (i) takes place at temperatures of 70 - 170 °C, preferably 100 - 150 °C (70 - 150 °C when using amine catalysts) over a period t 1 of preferably 120 min to 12 h, particularly preferably 150 min to 11 h.

[0055] The alkylene oxide (3) is fed continuously to the reactor in the usual manner so that the safety pressure limits of the reactor system used are not exceeded. Such reactions are usually carried out in the pressure range from 10 mbar to 10 bar. When dosing ethylene oxide-containing alkylene oxide mixtures or pure ethylene oxide, particular care must be taken to ensure that a sufficient inert gas partial pressure is maintained in the reactor during the start-up and dosing phases. This can be adjusted, for example, using noble gases or nitrogen. The alkylene oxides (3) can be fed to the reactor in various ways: Dosing is possible into the gas phase or directly into the liquid phase, e.g., via a dip tube or a distributor ring located near the reactor bottom in a well-mixed zone.When dosing into the liquid phase, the dosing units should be designed to be self-draining, for example, by installing the dosing holes on the underside of the distributor ring. Backflow of reaction medium into the alkylene oxide-carrying lines and dosing units, or into the alkylene oxide storage tanks, can advantageously be prevented by appropriate equipment, such as the installation of check valves.

[0056] The reaction of the first portion of the alkylene oxide (3) with the system (i) is preferably carried out at a temperature of 70 to 170 °C, particularly preferably at a temperature of 100 to 150 °C. The temperature can be varied during the alkylene oxide metering phase within the limits described: In order to achieve an optimal balance between high alkylene oxide conversion and low by-product formation when using sensitive starter compounds (such as sucrose), alkoxylation can initially be carried out at low reaction temperatures (for example at 70 to 110 °C), and only when the starter conversion is sufficient (i.e. as soon as at least 50% by mass of the starter compounds (1) used have reacted with alkylene oxide) can the reaction temperatures be changed to higher ones (for example to 110 to 130 °C).After the end of the metered addition phase for the first portion of the alkylene oxide (3), a post-reaction phase typically follows, in which the remaining alkylene oxide reacts. Post-reactions can optionally be carried out at higher temperatures (i.e., after raising the temperature to 100 to 170 °C, preferably 100 to 150 °C). The end of such a post-reaction phase is reached when, at an approximately constant temperature, no further or only a very slow pressure drop is detectable in the reaction vessel.

[0057] The temperature of the exothermic alkylene oxide addition reaction is maintained at the desired level by cooling. According to the state of the art for the design of polymerization reactors for exothermic reactions (e.g., Ullmann's Encyclopedia of Industrial Chemistry, Volume B4, page 167ff, 5th edition, 1992), such cooling generally takes place via the reactor wall (e.g., double jacket, half-coil) and by means of additional heat exchanger surfaces arranged internally in the reactor and / or externally in the pumped circulation circuit, e.g., on cooling coils, cooling candles, plate-and-tube, or mixer heat exchangers. These should advantageously be designed so that effective cooling can be achieved even at the beginning of the metering phase, i.e., at low fill levels and / or in the presence of a potentially heterogeneous reactor content (e.g., in the presence of solid dispersions, suspensions, or emulsions).

[0058] In one embodiment of the process according to the invention, in step (iii), the solvent (5) present, if any, is removed from the intermediate (ii) to form an intermediate (iii). In the process according to the invention, step (iii) is preferably carried out.

[0059] To reliably exclude the presence of solvent (5), preferably water as solvent (5), its removal from intermediate (ii) before addition of the fatty acid ester (2) can be assisted by vacuum at temperatures of 80-150 °C (40-130 °C when using amine catalysts), optionally by additional stripping with inert gas. If amines are used as catalysts, they can optionally be added only after such a dehydration step. After removal of the solvent (5), preferably water, intermediate (iii) results in step (iii).

[0060] In step (iv) of the process according to the invention, the fatty acid ester (2) is added to the intermediate (ii) or to the intermediate (iii) to form the intermediate (iv), n(2) mol of fatty acid ester groups being added to the intermediate (ii) or to the intermediate (iii).

[0061] In a preferred embodiment of the process according to the invention, in step (iv) the fatty acid ester (2) is added to the intermediate (iii) to form the intermediate (iv), n(2) mol of fatty acid ester groups being added to the intermediate (iii).

[0062] The number of moles n(2) of fatty acid ester groups added to intermediate (ii) or, optionally, to intermediate (iii) can be easily calculated by a person skilled in the art if the structure and molar mass of the fatty acid ester are known. For example, 2000 g of soybean oil triglyceride (molar mass: 880 Da) contains 6.8 moles of ester groups. Alternatively, if the structure of the fatty acid ester is unknown, the number of ester groups contained can also be determined using the saponification number according to DIN 53401.

[0063] Intermediate (iv) is prepared by stirring or pumping through a dispersing unit while inertizing the reaction vessel (e.g., by repeatedly pressurizing with nitrogen, followed each time by depressurizing to atmospheric pressure, and if necessary, evacuating to pressures < 1 bar). To facilitate mixing / dispersion of the components, stirring or pumping can be carried out at elevated temperature, for example, at 50 to 150 °C, and under an inert gas atmosphere (such as nitrogen). It is generally not necessary to adhere to a specific minimum stirring or pumping time.

[0064] In step (v) of the process according to the invention, n(3-2) moles of a second portion of the alkylene oxide (3) are added to the intermediate (iv) over a period of time t 2 to form the polyoxyalkylene polyester polyol according to the invention.

[0065] The recommended reaction conditions and apparatus parameters correspond to those already described for step (ii). Step (v) also generally concludes with a post-reaction step, which can also be carried out at higher temperatures (i.e. after raising the temperature to 100 to 170 °C, preferably 100 to 150 °C). The end of such a post-reaction phase is reached when, at an almost constant temperature, no further or only a very slow pressure drop can be detected in the reaction vessel. Such a criterion for the end of the post-reaction time can be individually determined. For example, a pressure drop rate of 20 mbar per hour is usually achieved at pressures in the range of approximately 2 bar or higher.If such a pressure drop rate specified for the post-reaction time is reached or undercut, it is recommended to reduce the temperature to values below 100 °C, preferably to values below 80 °C, in order to suppress the formation of undesirable secondary components.

[0066] The crude polyoxyalkylene polyetherester polyol resulting from step (v) can optionally be subjected to workup steps to remove or deactivate any traces of catalyst. In the case of amine-catalyzed alkylene oxide addition reactions, such post-treatment steps are generally not required. The optional removal of the catalyst from the crude polyoxyalkylene polyetherester polyol resulting from step (v) can be carried out in various ways: For example, the basic catalyst, e.g. KOH, can be neutralized with dilute mineral acids such as sulfuric acid or phosphoric acid. If strong dilute mineral acids (pKa of the 1stIf the polyoxyalkylene polyether ester polyols are to be neutralized (e.g., dissociation state < 2.8), the neutralization should be carried out at relatively low temperatures, for example, at 20 to 80 °C, preferably at 20 - 60 °C, and the amount of acid required for neutralization should be added to the alkaline alkylene oxide addition product as quickly as possible so that the basic reaction products are hydrolyzed and neutralized simultaneously. It is therefore advisable to dispense with a separate hydrolysis step before adding the neutralizing acid. With this procedure, side reactions at the ester bonds of the polyoxyalkylene polyether ester polyols are largely excluded. The salts formed during neutralization are separated off, for example, by filtration. Exceptions to this are the polyether polyol production processes described in EP-A 2028211 and WO-A 2009106244.Alternatively, neutralization can be carried out with hydroxycarboxylic acids (such as lactic acid, as described in WO-A 9820061 and US-A 2004167316). Carboxylic acids such as formic acid (cf. US 4,521,548) or adipic acid are also suitable for neutralization. In order to achieve a sufficiently high proton concentration in the polyoxyalkylene polyether ester polyol for the intended application, (hydroxy)carboxylic acids are often used in quantities significantly in excess of the amount of basic catalyst to be neutralized. The metal carboxylates formed after neutralization with some carboxylic acids (such as hydroxycarboxylic acids or formic acid) are clearly soluble in the polyoxyalkylene polyether ester polyols, so that separation of the salts can be omitted.Neutralization can also be achieved, for example, by adding cyclic dicarboxylic anhydrides, such as phthalic anhydride, maleic anhydride, tetrahydrophthalic anhydride, or succinic anhydride, which also yields salts soluble in the polyoxyalkylene polyether ester polyols according to the invention. Likewise, the use of ring-opening products of cyclic carboxylic anhydrides with polyols, i.e., dicarboxylic acid monoesters, as neutralizing agents is possible. Finally, it should be noted that the incompletely alkoxylated oxoacids of phosphorus are also suitable as neutralizing acids. The use of acidic cation exchangers, as described, for example, in DE-A 100 24 313, is also possible for catalyst removal.Furthermore, the catalysts can be separated using adsorbents such as layered silicates (bentonite, attapulgite), diatomaceous earth, or synthetic magnesium silicates (such as AMBOSOL ® or BriteSorb ® ). Such purification processes are described in RO 118433, US 4,507,475, EP-A 0693513, and EP-A 1751213. Phase separation processes represent, in principle, another option for separating catalyst residues; however, the water solubility of the polyoxyalkylene polyether ester polyols or of the components they contain is generally too high for effective phase separation processes. Phase separation processes are described, for example, in WO-A 0114456, JP-A 6-157743, WO-A 9620972, and US-A 3823145.

[0067] Antioxidants (e.g., based on phenol derivatives and / or aromatic amines) can be added to the polyoxyalkylene polyether ester polyols of the invention. If an alkali metal hydroxide is used to catalyze the alkylene oxide addition to the starter compounds used, it is recommended to add such antioxidants only after neutralization or removal of these catalyst traces, since this allows for the production of less strongly discolored polyoxyalkylene polyether ester polyols.

[0068] In a preferred embodiment of the process according to the invention, the mixing power input introduced in steps (i) to (v) is between 0.8 and 5 W / l, particularly preferably between 0.8 and 3 W / l, based on the liquid volume after completion of step (v), ie after completion of the metering of all reactants.

[0069] In general, thorough mixing of the reactor contents should be ensured in all reaction and / or mixing phases by designing and using commercially available stirring devices. Single- or multi-stage stirrers or stirrer types acting over a large area across the fill level are particularly suitable here (see, for example, Handbuch Apparate; Vulkan-Verlag Essen, 1st ed. (1990), pp. 188-208). Of particular technical relevance here is an average mixing power applied across the entire reactor contents, which, based on the liquid volume after completion of step (v), i.e. based on the fill level at the end of the dosing of all reactants, is in the range of 0.8 to 5 W / l, preferably in the range of 0.8 and 3 W / l, with correspondingly higher local power inputs in the area of the stirring devices themselves and, if necessary, at lower fill levels. To achieve optimal stirring, combinations of baffles (e.g.Flat or tubular baffles) and cooling coils (or cooling candles) can be arranged, which can also extend over the bottom of the container. The stirring power of the mixing unit can also be varied depending on the fill level during the dosing phase in order to ensure a particularly high energy input in critical reaction phases. For example, it can be advantageous to mix solid-containing dispersions, which may be present at the beginning of the reaction, for example when using sucrose, particularly intensively. Furthermore, especially when using solid H-functional starter compounds, the choice of stirring unit should ensure that the solid is sufficiently dispersed in the reaction mixture. Bottom-running stirring stages and stirring elements particularly suitable for suspension are preferred here. Furthermore, the stirrer geometry should contribute to reducing the foaming of reaction products.Foaming of reaction mixtures can be observed, for example, after the end of dosing and post-reaction phases when residual alkylene oxides are additionally removed under vacuum at absolute pressures in the range of 1 to 500 mbar. For such cases, agitators that achieve continuous mixing of the liquid surface have proven suitable. Depending on requirements, the agitator shaft has a bottom bearing and, if necessary, additional support bearings in the vessel. The agitator shaft can be driven from above or below (with a centric or eccentric shaft arrangement).

[0070] Alternatively, it is also possible to achieve the necessary mixing and the required mixing power input exclusively via a pumped circulation circuit via a heat exchanger or to operate this in addition to the stirring unit as an additional mixing component, with the reactor contents being pumped around as needed (typically 1 to 50 times per hour). The specific mixing power introduced by pumping, for example via an external heat exchanger or when returned to the reactor via a nozzle or injector, also amounts to values of on average 0.8 to 5 W / l, preferably 0.8 to 3 W / l, whereby this is related to the liquid volume in the reactor and the pumped circulation circuit after completion of the metering of all reactants, i.e. the fill level after completion of step (v).

[0071] It is recommended not only to carry out the production of the polyoxyalkylene polyester polyols according to the invention under exclusion of oxygen, but also to handle and store the corresponding finished products—i.e., fully processed, optionally salt-free, and stabilized by the addition of antioxidants—under exclusion of oxygen. Suitable inert gases for this purpose include noble gases, nitrogen, or carbon dioxide; noble gases or nitrogen are particularly suitable. By preventing the ingress of oxygen, further product discoloration can be largely avoided. This applies particularly at elevated temperatures, which are generally used to facilitate handling of the finished products by reducing product viscosity.Furthermore, significantly fewer peroxide groups are formed under an inert gas atmosphere, which, by cleaving existing polyether bonds, contribute to the formation of other low-molecular-weight oxidative degradation products such as acetaldehyde, methanol, formic acid, formic acid esters, acetone, and formaldehyde. This minimizes quality degradation during storage of finished products, reduces the content of volatile organic compounds, and prevents unpleasant odors and health risks.

[0072] The invention further relates to polyoxyalkylene polyester polyols obtainable by the process according to the invention.

[0073] According to the invention, the resulting polyoxyalkylene polyester polyol has a calculated OH number of 320 mg(KOH) / g to 530 mg(KOH) / g, preferably 350 mg(KOH) / g to 500 mg(KOH) / g.

[0074] The number-average OH functionality F n of the polyoxyalkylene polyester polyols obtainable by the process according to the invention is preferably at least 2.4, particularly preferably 2.4 to 4.8, the number-average functionality F n being calculated according to the following formula (1), F n = ∑ i n i × F i + ∑ j n j × F j + ∑ f n f × F f ∑ i n i + ∑ j n j + ∑ f n f where F i is the H functionality of the hydroxy-functional starter compound i, ni is the number of moles of hydroxy-functional starter compound i used, n j is the number of moles of amine-functional starter compound j used, F j is the number of aminic protons introduced per molecule of the aminic starter compound, n f is the number of moles of fatty acid ester f used, and F f is the hydroxy functionality of the fatty acid ester f. For example, soybean oil does not contain any fatty acid residues with OH groups, so f soybean oil = 0. Castor oil, on the other hand, has an OH functionality of 2.7 on average, so f castor oil = 2.7.

[0075] In one embodiment, the resulting polyoxyalkylene polyester polyol has a turbidity number (turbidity value) of ≤ 30 NTUs, preferably ≤ 20 NTUs, as determined according to US Environmental Protection Agency (USEPA) Method 180.1. The unit of measurement is NTU (nephelometric turbidity unit).

[0076] The present invention further provides a process for producing polyurethanes by reacting the polyoxyalkylene polyester polyol produced according to the invention with a polyisocyanate. The polyoxyalkylene polyester polyols can be used as starting components for the production of solid or foamed polyurethane materials, such as coatings or rigid foams for insulation purposes. Such polyurethane materials can also contain isocyanurate, allophanate, and biuret structural units.

[0077] To produce the foamed or solid polyurethane materials, the polyoxyalkylene polyester polyols according to the invention are optionally mixed with further isocyanate-reactive components and reacted with organic polyisocyanates, optionally in the presence of blowing agents, in the presence of catalysts and optionally in the presence of other additives, such as cell stabilizers.

[0078] As further isocyanate-reactive components, polyether polyols, polyester polyols, polycarbonate polyols, polyether carbonate polyols, polyester carbonate polyols, polyether ester carbonate polyols and / or low molecular weight chain extenders and / or crosslinking agents with OH numbers or NH numbers of 6 to 1870 mg KOH / g can optionally be added to the polyoxyalkylene polyester polyols according to the invention.

[0079] Polyether polyols suitable for this purpose can be obtained, for example, by anionic polymerization of alkylene oxides in the presence of alkali hydroxides or alkali alkoxides as catalysts and with the addition of at least one starter molecule containing 2 to 8 Zerewitinoff-active hydrogen atoms, or by cationic polymerization of alkylene oxides in the presence of Lewis acids such as antimony pentachloride, boron trifluoride etherate or tris(pentafluorophenyl)borane. Suitable catalysts are, of course, also those of the double metal cyanide complex type, so-called DMC catalysts, as described, for example, in US-A 3,404,109, US-A 3,829,505, US-A 3,941,849, US-A 5,158,922, US-A 5,470,813, EP-A 700,949, EP-A 743,093, EP-A 761,708, WO 97 / 40086, WO 98 / 16310, and WO 00 / 47649. Suitable alkylene oxides and some suitable starter compounds have already been described in previous sections.Also worth mentioning are tetrahydrofuran as a Lewis acid-polymerizable cyclic ether and water as the starter molecule. The polyether polyols, preferably polyoxypropylene-polyoxyethylene polyols, preferably have number-average molecular weights of 200 to 8000 Da. Also suitable as polyether polyols are polymer-modified polyether polyols, preferably graft polyether polyols, particularly those based on styrene and / or acrylonitrile, which are obtained by... in situ Polymerization of acrylonitrile, styrene or preferably mixtures of styrene and acrylonitrile, e.g. in a mass ratio of 90:10 to 10:90, preferably 70:30 to 30:70, advantageously prepared in the aforementioned polyether polyols, and polyether polyol dispersions which contain, as disperse phase, usually in an amount of 1 to 50% by mass, preferably 2 to 25% by mass, inorganic fillers, polyureas, polyhydrazides, polyurethanes containing tert-amino groups and / or melamine.

[0080] Suitable polyester polyols can be prepared, for example, from organic dicarboxylic acids having 2 to 12 carbon atoms and polyhydric alcohols, preferably diols, having 2 to 12 carbon atoms, preferably 2 to 6 carbon atoms. Examples of suitable dicarboxylic acids include: succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, and terephthalic acid. The dicarboxylic acids can be used individually or in mixtures with one another. Instead of the free dicarboxylic acids, the corresponding dicarboxylic acid derivatives, such as dicarboxylic acid monoesters and / or diesters of alcohols having 1 to 4 carbon atoms or dicarboxylic acid anhydrides, can also be used.Preferably, dicarboxylic acid mixtures of succinic, glutaric, and adipic acid are used in ratios of, for example, 20 to 35 / 40 to 60 / 20 to 36 parts by mass, and especially adipic acid. Examples of di- and polyhydric alcohols are ethanediol, diethylene glycol, 1,2- or 1,3-propanediol, dipropylene glycol, methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,10-decanediol, 1,12-dodecanediol, glycerol, trimethylolpropane, and pentaerythritol. Preference is given to using 1,2-ethanediol, diethylene glycol, 1,4-butanediol, 1,6-hexanediol, glycerol, trimethylolpropane, or mixtures of at least two of the polyhydric alcohols mentioned, in particular mixtures of ethanediol, 1,4-butanediol, and 1,6-hexanediol, glycerol, and / or trimethylolpropane. Polyester polyols derived from lactones, e.g., ε-caprolactone, or hydroxycarboxylic acids, e.g., hydroxycaproic acid and hydroxyacetic acid, can also be used.

[0081] To produce the polyester polyols, the organic, aromatic, or aliphatic polycarboxylic acids and / or polycarboxylic acid derivatives and polyhydric alcohols can be polycondensed catalyst-free or in the presence of esterification catalysts, advantageously in an atmosphere of inert gases such as nitrogen, helium, or argon, and also in the melt at temperatures of 150 to 300°C, preferably 180 to 230°C, optionally under reduced pressure, to the desired acid and OH numbers. The acid number of such polyester polyols is advantageously less than 10, preferably less than 2.5 mg KOH / g.

[0082] According to a preferred preparation process, the esterification mixture is polycondensed at the above-mentioned temperatures up to an acid number of 80 to 30 mg KOH / g, preferably 40 to 30 mg KOH / g, under atmospheric pressure and then under a pressure of less than 500 mbar, preferably 1 to 150 mbar. 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, the polycondensation of aromatic or aliphatic carboxylic acids with polyhydric alcohols can also be carried out in the liquid phase in the presence of diluents and / or entrainers, such as benzene, toluene, xylene or chlorobenzene, for azeotropic distillation of the condensation water.

[0083] The ratio of dicarboxylic acid (derivative) and polyhydric alcohol to be selected to obtain a desired OH number, functionality and viscosity and the alcohol functionality to be selected can be easily determined by the person skilled in the art.

[0084] Suitable polycarbonate polyols are those of a known type that can be prepared, for example, by reacting diols such as 1,2-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, oligotetramethylene glycol, and / or oligohexamethylene glycol with diaryl carbonates and / or dialkyl carbonates, e.g., diphenyl carbonate, dimethyl carbonate, and α-ω-bischloroformates or phosgene. Polyethercarbonate polyols, which are also suitable, are obtained by copolymerizing cyclic epoxides and carbon dioxide. Such copolymerizations are preferably carried out under high pressure and catalyzed by DMC compounds.

[0085] Low-molecular-weight difunctional chain extenders and / or low-molecular-weight, preferably tri- or tetrafunctional, crosslinking agents can be added to the polyoxyalkylene polyester polyols used according to the invention to modify the mechanical properties, in particular the hardness, of the PUR materials. Suitable chain extenders such as alkanediols, dialkylene glycols, and polyalkylene polyols and crosslinking agents, e.g., tri- or tetrahydric alcohols and oligomeric polyalkylene polyols with a functionality of 3 to 4, typically have molecular weights <800, preferably from 18 to 400, and in particular from 60 to 300 Da. Preferably used as chain extenders are alkanediols having 2 to 12 carbon atoms, e.g. ethanediol, 1,3-propanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol and in particular 1,4-butanediol and dialkylene glycols having 4 to 8 carbon atoms, e.g.Diethylene glycol and dipropylene glycol, as well as polyoxyalkylene glycols. Also suitable are branched-chain and / or unsaturated alkanediols with usually no more than 12 carbon atoms, such as: B. 1,2-propanediol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-butene-1,4-diol and 2-butyne-1,4-diol, diesters of terephthalic acid with glycols having 2 to 4 carbon atoms, such as terephthalic acid bis-ethylene glycol ester or terephthalic acid bis-1,4-butylene glycol ester and hydroxyalkylene ethers of hydroquinone or resorcinol, e.g. 1,4-di-(β-hydroxyethyl)-hydroquinone or 1,3-(β-hydroxyethyl)-resorcinol. Also alkanolamines with 2 to 12 carbon atoms such as ethanolamine, 2-aminopropanol and 3-amino-2,2-dimethylpropanol, N-alkyldialkanolamines, e.g.N-methyl- and N-ethyl-diethanolamine, (cyclo)aliphatic diamines having 2 to 15 carbon atoms, such as 1,2-ethylenediamine, 1,3-propylenediamine, 1,4-butylenediamine and 1,6-hexamethylenediamine, isophoronediamine, 1,4-cyclohexamethylenediamine and 4,4'-diaminodicyclohexylmethane, N-alkyl-, N,N'-dialkyl-substituted and aromatic diamines, which may also be substituted on the aromatic radical by alkyl groups, having 1 to 20, preferably 1 to 4 carbon atoms in the N-alkyl radical, such as N,N'-diethyl-, N,N'-disec.-pentyl-, N,N'-di-sec.-hexyl-, N,N'-di-sec.-decyl- and N,N'-dicyclohexyl-, p- or m-phenylenediamine, N,N'-dimethyl-, N,N'-diethyl-, N,N'-diisopropyl-, N,N'-di-sec.butyl-, N,N'-dicyclohexyl-4,4'-diamino-diphenylmethane, N,N'-di-sec.butylbenzidine, methylenebis(4-amino-3-benzoic acid methyl ester), 2,4-chloro-4,4'-diamino-diphenylmethane, 2,4- and 2,6-tolylenediamine can be used. Suitable crosslinking agents include glycerol, trimethylolpropane, or pentaerythritol.

[0086] Mixtures of different chain extenders and crosslinking agents as well as mixtures of chain extenders and crosslinking agents can also be used.

[0087] Suitable organic polyisocyanates are cycloaliphatic, araliphatic, aromatic and heterocyclic polyisocyanates, as described, for example, by W. Siefken in Justus Liebigs Annalen der Chemie, 562, pages 75 to 136, for example those of the formula Q(NCO) n in which n = 2-4, preferably 2, and Q is an aliphatic hydrocarbon radical with 2-18, preferably 5-10 C atoms, a cycloaliphatic hydrocarbon radical with 4-15, preferably 5-10 C atoms, an aromatic hydrocarbon radical with 6-15, preferably 6-13 C atoms, or an araliphatic hydrocarbon radical with 8-15, preferably 8-13 C atoms. Suitable are, for example:Ethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), 1,12-dodecane diisocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,3- and -1,4-diisocyanate and any mixtures of these isomers, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane (DE-B 1 202 785, US-A 3 401 190), 2,4- and 2,6-hexahydrotoluene diisocyanate and any mixtures of these isomers, hexahydro-1,3- and -1,4-phenylene diisocyanate, perhydro-2,4'- and -4,4'-diphenylmethane diisocyanate, 1,3- and 1,4-phenylene diisocyanate (DE-A 196 27 907), 1,4-durene diisocyanate (DDI), 4,4'-stilbene diisocyanate (DE-A 196 28 145), 3,3'-dimethyl-4,4'-biphenylene diisocyanate (DIBDI) (DE-A 195 09 819), 2,4- and 2,6-tolylene diisocyanate (TDI) and any mixtures of these isomers, diphenylmethane 2,4'-diisocyanate and / or diphenylmethane 4,4'-diisocyanate (MDI) or naphthylene 1,5-diisocyanate (NDI).

[0088] Further examples of suitable compounds according to the invention are: triphenylmethane-4,4',4"-triisocyanate, polyphenyl-polymethylene polyisocyanates, as obtained by aniline-formaldehyde condensation and subsequent phosgenation and described, for example, in GB-A 874 430 and GB-A 848 671, m- and p-isocyanatophenylsulfonyl isocyanates according to US-A 3 454 606, perchlorinated aryl polyisocyanates, as described in US-A 3 277 138, polyisocyanates containing carbodiimide groups, as described in US-A 3 152 162 and in DE-A 25 04 400, 25 37 685 and 25 52 350, norbornane diisocyanates according to US-A 3 492 301, polyisocyanates containing allophanate groups, as described in GB-A 994 890, BE-B 761 626 and NL-A 7 102 524, polyisocyanates containing isocyanurate groups, as described in US-A 3 001 9731, in DE-C 10 22 789, 12 22 067 and 1 027 394 as well as in DE-A 1 929 034 and 2 004 048, polyisocyanates containing urethane groups, as described e.g.in BE-B 752 261 or in US-A 3 394 164 and 3 644 457, polyisocyanates containing acylated urea groups according to DE-C 1 230 778, polyisocyanates containing biuret groups as described in US-A 3 124 605, 3 201 372 and 3 124 605 and in GB-B 889 050, polyisocyanates prepared by telomerization reactions as described in US-A 3 654 106, polyisocyanates containing ester groups as mentioned in GB-B 965 474 and 1 072 956, in US-A 3 567 763 and in DE-C 1 231 688, reaction products of the abovementioned isocyanates with Acetals according to DE-C 1 072 385 and polyisocyanates containing polymeric fatty acid esters according to US-A 3 455 883.

[0089] It is also possible to use the distillation residues containing isocyanate groups obtained during industrial isocyanate production, optionally dissolved in one or more of the aforementioned polyisocyanates. Furthermore, it is possible to use any mixtures of the aforementioned polyisocyanates.

[0090] Preferred polyisocyanates are those that are readily available industrially, e.g., tolylene 2,4- and 2,6-diisocyanate and any mixtures of these isomers ("TDI"), polyphenylpolymethylene polyisocyanates, such as those produced by aniline-formaldehyde condensation followed by phosgenation ("crude MDI"), and polyisocyanates containing carbodiimide groups, urethane groups, allophanate groups, isocyanurate groups, urea groups, or biuret groups ("modified polyisocyanates"), particularly those modified polyisocyanates derived from tolylene 2,4- and / or 2,6-diisocyanate or from diphenylmethane 4,4'- and / or 2,4'-diisocyanate. Naphthylene 1,5-diisocyanate and mixtures of the polyisocyanates mentioned are also well suited.

[0091] It is also possible to use prepolymers containing isocyanate groups, which are obtainable by reacting a portion or all of the polyoxyalkylene polyester polyols to be used according to the invention and / or a portion or all of the isocyanate-reactive components described above, which may be admixed with the polyoxyalkylene polyester polyols to be used according to the invention, with at least one aromatic di- or polyisocyanate from the group consisting of TDI, MDI, DIBDI, NDI, and DDI, preferably with 4,4'-MDI and / or 2,4-TDI and / or 1,5-NDI, to form a polyaddition product containing urethane groups, preferably urethane groups and isocyanate groups. Such polyaddition products have NCO contents of 20.0 to 40.0% by mass.According to a preferred embodiment, the prepolymers containing isocyanate groups are prepared by reacting exclusively higher molecular weight polyhydroxyl compounds, i.e. the polyoxyalkylene polyester polyols and / or polyether polyols, polyester polyols or polycarbonate polyols to be used according to the invention, with the polyisocyanates, preferably 4,4'-MDI and / or 2,4-TDI.

[0092] The prepolymers containing isocyanate groups can be produced in the presence of catalysts. However, it is also possible to produce the prepolymers containing isocyanate groups in the absence of catalysts and add them to the reaction mixture for producing the PUR materials.

[0093] As a blowing agent to be used for the purpose of foam production, water can be used which is mixed with the organic polyisocyanates or with the prepolymers containing isocyanate groups in situreacts to form carbon dioxide and amino groups, which in turn react with other isocyanate groups to form urea groups, thereby acting as chain extenders. If water is added to the polyurethane formulation to adjust the desired density, it is typically used in amounts of 0.001 to 6.0% by mass, based on the mass of the polyoxyalkylene polyester polyols according to the invention, optionally other isocyanate-reactive components, the catalysts, and other additives.

[0094] Instead of water, or preferably in combination with water, gases or highly volatile inorganic or organic substances that evaporate under the influence of the exothermic polyaddition reaction and advantageously have a boiling point under atmospheric pressure in the range of -40 to 120 °C, preferably from 10 to 90 °C, can be used as physical blowing agents. Examples of organic blowing agents that can be used include acetone, ethyl acetate, methyl acetate, halogen-substituted alkanes such as methylene chloride, chloroform, ethylidene chloride, vinylidene chloride, monofluorotrichloromethane, chlorodifluoromethane, dichlorodifluoromethane, HFCs such as R 134a, R 245fa, and R 365mfc, partially fluorinated olefins ("hydrofluoroolefins", HFOs), and unsubstituted alkanes such as butane, n-pentane, isopentane, cyclopentane, hexane, heptane, or diethyl ether. Inorganic propellants such as air, CO 2 or N 2 O can be used.A propellant effect can also be achieved by adding compounds which decompose at temperatures above room temperature with the release of gases, for example nitrogen and / or carbon dioxide, such as azo compounds, e.g. azodicarbonamide or azoisobutyronitrile or salts such as ammonium bicarbonate, ammonium carbamate or ammonium salts of organic carboxylic acids, e.g. the monoammonium salts of malonic acid, boric acid, formic acid or acetic acid. Further examples of blowing agents, details on the use of blowing agents and criteria for the selection of blowing agents are described in R. Vieweg, A. Höchtlen (eds.): "Kunststoff-Handbuch", Volume VII, Carl-Hanser-Verlag, Munich 1966, pp. 108f, 453ff and 507-5 10 as well as in D. Randall, S. Lee (eds.): "The Polyurethanes Book", John Wiley & Sons, Ltd., London 2002, pp. 127 - 136, pp. 232 - 233 and p. 261.

[0095] The appropriate amount of solid blowing agents, low-boiling liquids, or gases, which can be used individually or in the form of mixtures, e.g., as liquid or gas mixtures or as gas-liquid mixtures, depends on the desired polyurethane material density and the amount of water used. The required quantities can be easily determined experimentally.

[0096] In the absence of moisture and physically or chemically acting blowing agents, compact PUR materials can of course also be produced.

[0097] Amine catalysts familiar to the expert and proven for the production of polyurethane materials include: B. tertiary amines such as triethylamine, tributylamine, N-methylmorpholine, N-ethylmorpholine, N,N,N',N'-tetramethylethylenediamine, pentamethyldiethylenetriamine and higher homologues (DE-OS 26 24 527 and 26 24 528), 1,4-diazabicyclo-(2,2,2)-octane, N-methyl-N'-dimethylaminoethylpiperazine, bis-(dimethylaminoalkyl)-piperazine (DE-A 26 36 787), N,N-dimethylbenzylamine, N,N-dimethylcyclohexylamine, N,N-diethylbenzylamine, bis-(N,N-diethylaminoethyl)adipate, N,N,N',N'-tetramethyl-1,3-butanediamine, N,N-Dimethyl-β-phenyl-ethyl-amine, bis-(dimethylaminopropyl)-urea, 1,2-dimethylimidazole, 2-methylimidazole, monocyclic and bicyclic amidines (DE-A 17 20 633), bis-(dialkylamino)-alkyl ethers (US-A 3 330 782, DE-B 10 30 558, DE-A 18 04 361 and 26 18 280) and tertiary amines containing amide groups (preferably formamide groups) according to DE-A 25 23 633 and 27 32 292).Also suitable as catalysts are known Mannich bases made from secondary amines, such as dimethylamine, and aldehydes, preferably formaldehyde, or ketones, such as acetone, methyl ethyl ketone or cyclohexanone and phenols, such as phenol or alkyl-substituted phenols. Tertiary amines containing hydrogen atoms active towards isocyanate groups which can be used as catalysts include triethanolamine, triisopropanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N,N-dimethylethanolamine, their reaction products with alkylene oxides such as propylene oxide and / or ethylene oxide, and secondary tertiary amines according to DE-A 27 32 292. Silaamines with carbon-silicon bonds, as described in US-A 3 620 984, can also be used as catalysts, e.g. 2,2,4-trimethyl-2-silamorpholine and 1,3-diethylaminomethyltetramethyldisiloxane. Nitrogen-containing bases such as tetraalkylammonium hydroxides and hexahydrotriazines are also suitable.The reaction between NCO groups and Zerewitinoff-active hydrogen atoms is also strongly accelerated by lactams and azalactams, whereby an association is initially formed between the lactam and the compound with acidic hydrogen.

[0098] If amines are used as catalysts to catalyze the polyurethane reaction, it should of course be noted that polyoxyalkylene polyester polyols according to the invention, possibly prepared under amine catalysis, may already contain catalytically active amines. However, by conducting suitable test series, it is readily possible for the skilled person to determine the amounts of amine catalysts that should advantageously be added.

[0099] Furthermore, conventional organic metal compounds can be used as catalysts for this purpose, preferably organic tin compounds such as tin(II) salts of organic carboxylic acids, e.g., tin(II) acetate, tin(II) octoate, tin(II) ethylhexoate, and tin(II) taurate, and the dialkyltin(IV) salts of mineral acids or organic carboxylic acids, e.g., dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate, dioctyltin diacetate, and dibutyltin dichloride. Sulfur-containing compounds such as di-n-octyltin mercaptide (US Pat. No. 3,645,927) can also be used.

[0100] Catalysts that specifically catalyze the trimerization of NCO groups are used to produce polyurethane materials with high proportions of so-called poly(isocyanurate) structures ("PIR foams"). Typically, formulations with significant excesses of NCO groups over OH groups are used to produce such materials. PIR foams are typically produced with densities of 180 to 450, where the densities are defined as the molar ratio of isocyanate groups to hydroxyl groups multiplied by a factor of 100. Catalysts that contribute to the formation of isocyanurate structures include metal salts such as potassium or sodium acetate, sodium octoate, and amino compounds such as 1,3,5-tris(3-dimethylaminopropyl)hexahydrotriazine.

[0101] The catalysts or catalyst combinations are generally used in an amount of between about 0.001 and 10% by mass, in particular 0.01 to 4% by mass, based on the total amount of compounds having at least two hydrogen atoms reactive towards isocyanates.

[0102] During the production of compact or foamed PUR materials, additives may be used if necessary. Examples include surface-active additives such as emulsifiers, foam stabilizers, cell regulators, flame retardants, nucleating agents, antioxidants, stabilizers, lubricants and mold release agents, dyes, dispersing aids, and pigments. Emulsifiers include, for example, the sodium salts of castor oil sulfonates or salts of fatty acids with amines such as diethylamine oleate or diethanolamine stearate. Alkali or ammonium salts of sulfonic acids such as dodecylbenzenesulfonic acid or dinaphthylmethanedisulfonic acid, or of fatty acids such as ricinoleic acid, or of polymeric fatty acids. Polyether siloxanes are particularly suitable as foam stabilizers.These compounds are generally constructed by combining copolymers of ethylene oxide and propylene oxide with a polydimethylsiloxane residue. Such foam stabilizers can be reactive toward isocyanates or, due to etherification of the terminal OH groups, unreactive toward isocyanates. They are described, for example, in US Pat. Nos. 2,834,748, 2,917,480, and 3,629,308. General structures of such foam stabilizers are given in G. Oertel (ed.): "Kunststoff-Handbuch," Volume VII, Carl-Hanser-Verlag, Munich, Vienna 1993, pp. 113-115. Of particular interest are polysiloxane-polyoxyalkylene copolymers according to DE-A 25 58 523, which are often branched via allophanate groups. Other organopolysiloxanes, oxyethylated alkylphenols, oxyethylated fatty alcohols and paraffin oils, and cell regulators such as paraffins, fatty alcohols and dimethylpolysiloxanes are also suitable.Oligomeric polyacrylates with polyoxyalkylene and fluoroalkane residues as side groups are also suitable for improving the emulsifying effect, the dispersion of the filler, the cell structure, and / or for their stabilization. The surface-active substances are usually used in amounts of 0.01 to 5 parts by mass, based on 100 parts by mass of the total amount of compounds containing hydrogen atoms reactive towards isocyanates. Reaction retarders, e.g., acidic substances such as hydrochloric acid, or organic acids and acid halides, as well as pigments or dyes and known flame retardants, e.g., tris(chloroethyl) phosphate, triethyl phosphate, tricresyl phosphate, or ammonium phosphate and polyphosphate, as well as stabilizers against aging and weathering, plasticizers, and fungicidal and bactericidal substances, may also be added.Further examples of surface-active additives and foam stabilizers, as well as cell regulators, reaction retarders, stabilizers, flame-retardant substances, plasticizers, dyes and fillers, as well as fungistatic and bacteriostatic substances, which may optionally be used according to the invention, as well as details on the use and mode of action of these additives, are described in R. Vieweg, A. Höchtlen (eds.): "Kunststoff-Handbuch", Volume VII, Carl-Hanser-Verlag, Munich 1966, pp. 103-113.

[0103] The PUR materials can be produced according to the processes described in the literature, e.g. the one-shot or the prepolymer process, with the aid of mixing devices known in principle to the person skilled in the art. Examples of the preparation of the polyoxyalkylene polyester polyols according to the invention Raw materials used: Soybean oil:

[0104] Soybean oil (refined, i.e., delecithinized, neutralized, decolorized, and steam-stripped), purchased from Sigma-Aldrich Chemie GmbH, Munich. Irganox ®< 1076:

[0105] Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate

[0106] Unless otherwise stated, percentages are to be understood as percentages by mass. Methods: OH number determination

[0107] The OH numbers were determined according to DIN 53240. Determination of viscosity

[0108] The viscosity was determined according to DIN 53019 using a Stabinger viscometer (Stabinger SVM 3000, manufacturer: Anton Paar) Determination of turbidity

[0109] The turbidity values were determined according to US Environmental Protection Agency (USEPA) Method 180.1. The unit of measurement is NTU (nephelometric turbidity unit). Example 1 (inventive)

[0110] 835.5 g of a 70% solution of sorbitol in water, 1099.0 g of sucrose, 153.4 g of distilled water, and 10.58 g of imidazole were placed in a 10 l laboratory autoclave under a nitrogen atmosphere. After closing the autoclave, residual oxygen was removed by applying nitrogen five times to an absolute pressure of 5 bar while the stirrer was running (200 rpm, grid stirrer), followed by depressurization to atmospheric pressure. The reactor was then heated to 110 °C while stirring (200 rpm, grid stirrer). Once this temperature was reached, the stirrer speed was increased to 450 rpm (corresponding to a power input of approximately 4.6 W / l, based on the fill level at the end of the metered addition of all reactants). At this temperature, 1179.3 g of propylene oxide were initially added over a total period of 9.2 h. After the addition of this first propylene oxide block, a post-reaction time of 4 h followed.The contents of the autoclave were then stripped over a period of 3.5 h at 110 °C while stirring at 100 rpm under vacuum at a pressure of approximately 125 mbar, while introducing 50 ml of nitrogen per minute through a distributor ring located below the liquid level, to remove the water. The autoclave was then cooled to 30 °C, and 3138.0 g of soybean oil were added. After closing the autoclave, residual oxygen was removed during the heating phase by twice applying nitrogen to an absolute pressure of 5 bar and then evacuating to 10 mbar. After the reaction temperature of 110 °C was reached again and the stirrer speed was set to 450 rpm, 300 g of propylene oxide were metered in over a period of 9.72 h. After the dosing of this second propylene oxide block was completed, a post-reaction time of 3 h followed.Finally, the contents of the autoclave were heated to reaction temperature under vacuum at approximately 5 mbar for 30 minutes. During the cooling phase, 2.534 g of IRGANOX ®< 1076 were added. A clear product was obtained at room temperature with a measured OH number of 385 mg KOH / g and a viscosity of 17,550 mPas at 25 °C. The turbidity value was 4.1 NTUs. Example 2 (Comparison)

[0111] 835.4 g of a 70% solution of sorbitol in water, 1099.2 g of sucrose, 154.1 g of distilled water, and 10.55 g of imidazole were placed in a 10 l laboratory autoclave under a nitrogen atmosphere. After closing the autoclave, residual oxygen was removed from it by pressurizing it with nitrogen five times to an absolute pressure of 5 bar while the stirrer was running (200 rpm, grid stirrer), followed by depressurization to atmospheric pressure. The reactor was then heated to 110 °C while stirring. Once this temperature was reached, the stirrer speed was increased to 450 rpm (corresponding to a power input of approximately 4.6 W / l, based on the fill level at the end of the metering of all reactants). At this temperature, 1179.3 g of propylene oxide were initially metered in over a total period of 2.7 h. After the dosing of this first propylene oxide block was completed, a post-reaction time of 1.33 h followed.The contents of the autoclave were then stripped over a period of 3.5 h at 110 °C while stirring at 100 rpm under vacuum at a pressure of approximately 125 mbar, while introducing 50 ml of nitrogen per minute through a distributor ring located below the liquid level, thus removing the water. The autoclave was then cooled to 30 °C, and 3140.6 g of soybean oil were added. After closing the reactor, residual oxygen was removed during the heating phase by twice pressurizing the autoclave with nitrogen to an absolute pressure of 5 bar and then evacuating to 10 mbar. After the reaction temperature of 110 °C was reached again and the stirrer speed was set to 450 rpm, 300 g of propylene oxide were metered in over a period of 1.22 h. After the dosing of this second propylene oxide block was completed, a post-reaction time of 3 h followed.Finally, the contents of the autoclave were heated at reaction temperature for 30 minutes under vacuum at approximately 5 mbar. During the cooling phase, 2.496 g of IRGANOX ®< 1076 were added. A two-phase product was obtained for which no analytical data could be determined. Example 3 (Comparison)

[0112] 835.2 g of a 70% solution of sorbitol in water, 1199.0 g of sucrose, 150.4 g of distilled water, and 10.48 g of imidazole were placed in a 10 l laboratory autoclave under a nitrogen atmosphere. After closing the autoclave, residual oxygen was removed by applying nitrogen five times to an absolute pressure of 5 bar while the stirrer was running (200 rpm, grid stirrer), followed by depressurization to atmospheric pressure. The reactor was then heated to 110 °C while stirring (200 rpm, grid stirrer). Once this temperature was reached, the stirrer speed was increased to 450 rpm (corresponding to a power input of approximately 4.6 W / l, based on the fill level at the end of the metered addition of all reactants). At this temperature, 1000.0 g of propylene oxide were initially added over a total period of 10.02 h. After the addition of this first propylene oxide block, a post-reaction time of 2.5 h followed.The contents of the autoclave were then stripped over a period of 3.1 h at 110 °C while stirring at 200 rpm under vacuum at a pressure of approximately 110 mbar, with 50 ml of nitrogen introduced per minute through a distributor ring located below the liquid level, to remove the water. The autoclave was then cooled to 30 °C, and 3138.1 g of soybean oil were added. After closing the autoclave, residual oxygen was removed during the heating phase by twice applying nitrogen to an absolute pressure of 5 bar and then evacuating to 10 mbar. After the reaction temperature of 110 °C was reached again and the stirrer speed was set to 450 rpm, 479.2 g of propylene oxide were metered in over a period of 10.23 h. After the dosing of this second propylene oxide block was completed, a post-reaction time of 2.18 h followed.Finally, the contents of the autoclave were heated to reaction temperature under vacuum at approximately 4 mbar for 30 minutes. During the cooling phase, 2.490 g of IRGANOX ®< 1076 were added. A product was obtained that was cloudy at room temperature with a measured OH number of 398 mg KOH / g and a viscosity of 24,150 mPas at 25 °C. The turbidity value was 35.30 NTUs. Example 4 (Comparison)

[0113] 835.4 g of a 70% solution of sorbitol in water, 1098.0 g of sucrose, 150.0 g of distilled water, and 10.52 g of imidazole were placed in a 10 l laboratory autoclave under a nitrogen atmosphere. After closing the autoclave, residual oxygen was removed by applying nitrogen five times to an absolute pressure of 5 bar while the stirrer was running (200 rpm, grid stirrer), followed by evacuation to 10-20 mbar. The reactor was then heated to 110 °C while stirring (200 rpm, grid stirrer). Once this temperature was reached, the stirrer speed was increased to 450 rpm (corresponding to a power input of approximately 4.6 W / l, based on the fill level at the end of the metering of all reactants). At this temperature, 1000.0 g of propylene oxide were initially added over a total period of 10.2 h. After the addition of this first propylene oxide block, a post-reaction time of 1.8 h followed.The contents of the autoclave were then stripped over a period of 3.1 h at 110 °C while stirring at 250 rpm under vacuum at a pressure of approximately 125 mbar, with 50 ml of nitrogen introduced per minute through a distributor ring located below the liquid level, to remove the water. The autoclave was then cooled to 40 °C, and 3138.0 g of soybean oil were added. After closing the autoclave, residual oxygen was removed during the heating phase by pressurizing it five times with nitrogen to an absolute pressure of 4 bar and then depressurizing to atmospheric pressure. After the reaction temperature of 110 °C was reached again and the stirrer speed was set to 450 rpm, the system was evacuated to 90 mbar, and 479.2 g of propylene oxide were metered in over a period of 8.2 h. After the dosing of this second propylene oxide block was completed, a post-reaction time of 1.4 h followed.Finally, the contents of the autoclave were heated at reaction temperature for 40 minutes under vacuum at approximately 30 mbar. During the cooling phase, 2.526 g of IRGANOX ®< 1076 were added. A biphasic product was obtained at room temperature, for which no analytical data could be determined. Example 5 (Comparison)

[0114] 835.3 g of a 70% solution of sorbitol in water, 1098.5 g of sucrose, 150.0 g of distilled water, and 10.50 g of imidazole were placed in a 10 l laboratory autoclave under a nitrogen atmosphere. After sealing the autoclave, residual oxygen was removed by applying nitrogen five times to an absolute pressure of 5 bar, followed by evacuation to 200 mbar, while the stirrer was running (100 rpm, grid stirrer). The reactor was then heated to 110 °C with stirring (450 rpm, grid stirrer). At this temperature, 1000.0 g of propylene oxide were initially metered in over a total period of 10.2 h while stirring at 450 rpm (corresponding to a power input of approximately 4.6 W / l, based on the fill level at the end of the metering of all reactants). After the end of metering of this first propylene oxide block, a post-reaction time of 2.0 h followed.The contents of the autoclave were then stripped over a period of 3.1 h at 110 °C while stirring at 100 rpm under vacuum at a pressure of approximately 125 mbar, with 50 ml of nitrogen per minute being introduced through a distributor ring located below the liquid level, thus removing the water. The autoclave was then cooled to 25 °C, and 3137.7 g of soybean oil were added. After closing the autoclave, residual oxygen was removed during the heating phase by pressurizing it five times with nitrogen to an absolute pressure of 5 bar and then depressurizing to atmospheric pressure. After the reaction temperature of 110 °C was reached again and the stirrer speed was set to 450 rpm, 479.3 g of propylene oxide were metered in over a period of 2.0 h. After the dosing of this second propylene oxide block was completed, a post-reaction time of 4.45 h followed.Finally, the contents of the autoclave were heated at reaction temperature for 50 minutes under vacuum at approximately 30 mbar. During the cooling phase, 2.526 g of IRGANOX ®< 1076 were added. A biphasic product was obtained at room temperature, for which no analytical data were determined. Example 6 (Comparison)

[0115] 907.4 g of a 70% solution of sorbitol in water, 1193.5 g of sucrose, 163.0 g of distilled water, and 11.46 g of imidazole were placed in a 10 l laboratory autoclave under a nitrogen atmosphere. After closing the autoclave, residual oxygen was removed from it by applying nitrogen four times to an absolute pressure of 4 bar while the stirrer was running (250 rpm, grid stirrer), followed by evacuation to 100 mbar. The reactor was then heated to 110 °C while stirring. The stirrer speed was increased to 450 rpm (corresponding to a power input of approximately 4.6 W / l, based on the fill level at the end of the metering of all reactants), and at this temperature, 1086.4 g of propylene oxide were initially metered in over a total period of 10.2 h. After the first propylene oxide block was added, a post-reaction time of 1.4 hours followed. The contents of the autoclave were then heated to 110 °C for 3.1 hours while stirring at 100 rpm.in a vacuum at a pressure of approximately 120 mbar while introducing 50 ml of nitrogen per minute through a distributor ring located below the liquid level, thus removing the water. The autoclave was then cooled to 20 °C, and 3409.2 g of soybean oil were added. After closing the autoclave, residual oxygen was removed during the heating phase by pressurizing it five times with nitrogen to an absolute pressure of 4 bar and then evacuating it to 110 mbar. After the reaction temperature of 110 °C was reached again and the stirrer speed was set to 450 rpm, 760.6 g of propylene oxide were metered in over a period of 2.2 h. After the metering of this second propylene oxide block was completed, a post-reaction time of 3.8 h followed. Finally, the contents of the autoclave were heated at reaction temperature for a period of 30 min in vacuum at approximately 25 mbar.During the cooling phase, 3.637 g of IRGANOX ®< 1076 were added. A product was obtained that was clear at room temperature with a measured OH number of 376 mg KOH / g and a viscosity at 25 °C of 14150 mPas. Example 7 (inventive)

[0116] 836.6 g of a 70% solution of sorbitol in water, 1098.5 g of sucrose, 150.0 g of distilled water, and 10.52 g of imidazole were placed in a 10 l laboratory autoclave under a nitrogen atmosphere. After closing the autoclave, residual oxygen was removed by applying nitrogen five times to an absolute pressure of 5 bar while the stirrer was running (100 rpm, grid stirrer), followed by depressurization to atmospheric pressure. The reactor was then heated to 110 °C while stirring (100 rpm, grid stirrer). Once this temperature was reached, the stirrer speed was increased to 450 rpm (corresponding to a power input of approximately 4.6 W / l, based on the fill level at the end of the metering of all reactants). At this temperature, 1279.2 g of propylene oxide were initially added over a total period of 10.13 h. After the addition of this first propylene oxide block, a post-reaction time of 1.5 h followed.The contents of the autoclave were then stripped over a period of 3.5 h at 110 °C while stirring at 100 rpm under vacuum at a pressure of approximately 140 mbar, with 50 ml of nitrogen introduced per minute through a distributor ring located below the liquid level, thus removing the water. The autoclave was then cooled to 25 °C, and 3139.0 g of soybean oil were added. After closing the autoclave, residual oxygen was removed by pressurizing it five times with nitrogen to an absolute pressure of 5 bar, followed by depressurization to atmospheric pressure. After the reaction temperature of 110 °C was reached again and the stirrer speed was set to 450 rpm, 200.0 g of propylene oxide were metered in over a period of 12.07 h. After the metering of this second propylene oxide block was completed, a post-reaction time of 1.3 h followed. Finally, the contents of the autoclave were heated at reaction temperature for a period of 30 min.under vacuum at approximately 30 mbar. During the cooling phase, 2.52 g of IRGANOX ®< 1076 were added. A product was obtained that was clear at room temperature with a measured OH number of 392 mg KOH / g and a viscosity of 24,750 mPas at 25 °C. Example 8 (inventive)

[0117] 835.2 g of a 70% solution of sorbitol in water, 1099.1 g of sucrose, 150.0 g of distilled water, and 10.55 g of imidazole were placed in a 10 l laboratory autoclave under a nitrogen atmosphere. After closing the autoclave, residual oxygen was removed from it by applying nitrogen three times to an absolute pressure of 5 bar while the stirrer was running (200 rpm, grid stirrer), followed by evacuation to approximately 110 mbar. The reactor was then heated to 110 °C while stirring (200 rpm, grid stirrer). Once this temperature was reached, the stirrer speed was increased to 350 rpm (corresponding to a power input of approximately 2.1 W / l, based on the fill level at the end of the metering of all reactants). At this temperature, 1179.2 g of propylene oxide were initially added over a total period of 10.13 h. After the addition of this first propylene oxide block, a post-reaction time of 1.5 h followed.The contents of the autoclave were then stripped over a period of 2.0 h at 110 °C while stirring at 200 rpm under vacuum at a pressure of approximately 110 mbar, with 50 ml of nitrogen per minute being introduced through a distributor ring located below the liquid level, thus removing the water. The autoclave was then cooled to 20 °C, and 3139.2 g of soybean oil were added. After closing the autoclave, residual oxygen was removed from it during the heating phase by applying nitrogen four times to an absolute pressure of 3 bar and then evacuating to 70 mbar. After the reaction temperature of 110 °C was reached again and the stirrer speed was set to 350 rpm, 300.0 g of propylene oxide were metered in over a period of 8.6 h. After the dosing of this second propylene oxide block was completed, a post-reaction time of 2.1 h followed.Finally, the contents of the autoclave were heated at reaction temperature for 30 minutes under vacuum at approximately 30 mbar. During the cooling phase, 2.535 g of IRGANOX ®< 1076 were added. A clear product was obtained at room temperature with a measured OH number of 388 mg KOH / g and a viscosity of 24,100 mPas at 25 °C. Example 9 (Comparison)

[0118] 835.4 g of a 70% solution of sorbitol in water, 1099.2 g of sucrose, 150.0 g of distilled water, and 10.65 g of imidazole were placed in a 10 l laboratory autoclave under a nitrogen atmosphere. After closing the autoclave, residual oxygen was removed from it by pressurizing it with nitrogen five times to an absolute pressure of 5 bar while the stirrer was running (100 rpm, grid stirrer), followed by depressurization to atmospheric pressure. The reactor was then heated to 110 °C while stirring (450 rpm, grid stirrer, corresponding to a power input of approximately 4.6 W / l, based on the fill level at the end of the metering of all reactants). At this temperature, 1179.2 g of propylene oxide were initially metered in over a total period of 9.33 h. After the first propylene oxide block was added, a post-reaction period of 2.5 hours followed. The contents of the autoclave were then heated to 110 °C for 3.5 hours while stirring at 100 rpm.in a vacuum at a pressure of approximately 150 mbar while introducing 50 ml of nitrogen per minute through a distributor ring located below the liquid level, thus removing the water. The autoclave was then cooled to 40 °C and 3138.1 g of soybean oil were added. After closing the autoclave, residual oxygen was removed by pressurizing it with nitrogen five times to an absolute pressure of 5 bar and then releasing it to atmospheric pressure. The mixture was then heated again to the reaction temperature of 110 °C and the stirrer speed was increased to 450 rpm. Subsequently, 300.1 g of propylene oxide were metered in over a period of 1.25 h. After the end of the metering of this second propylene oxide block, a post-reaction time of 6 h followed. Finally, the contents of the autoclave were baked out at reaction temperature over a period of 30 min in a vacuum at approximately 33 mbar.During the cooling phase, 2.531 g of IRGANOX ®< 1076 were added. A biphasic product was obtained at room temperature, for which no analytical data could be determined. Example 10 (inventive)

[0119] 838.2 g of a 70% solution of sorbitol in water, 1098.6 g of sucrose, 150.0 g of distilled water, and 10.58 g of imidazole were placed in a 10 l laboratory autoclave under a nitrogen atmosphere. After closing the autoclave, residual oxygen was removed by applying nitrogen three times to an absolute pressure of 5 bar while the stirrer was running (100 rpm, grid stirrer), followed by evacuation to approximately 80 mbar. The reactor was then heated to 110 °C while stirring (100 rpm, grid stirrer). Once this temperature was reached, the stirrer speed was increased to 270 rpm (corresponding to a power input of approximately 1.1 W / l, based on the fill level at the end of the metering of all reactants). At this temperature, 1179.3 g of propylene oxide were initially added over a total period of 10.15 h. After the addition of this first propylene oxide block, a post-reaction time of 2.1 h followed.The contents of the autoclave were then stripped of water over a period of 3.0 h at 110 °C while stirring at 200 rpm under vacuum at a pressure of approximately 125 mbar, while introducing 50 ml of nitrogen per minute through a distributor ring located below the liquid level. The autoclave was then cooled to 45 °C, and 3137.7 g of soybean oil were added while stirring at 100 rpm. After closing the autoclave, residual oxygen was removed by pressurizing it five times with nitrogen to an absolute pressure of 5 bar, followed by depressurizing to atmospheric pressure. The autoclave contents were then heated again to 110 °C while stirring at 100 rpm. After the reaction temperature of 110 °C was reached again and the stirrer speed was adjusted to 270 rpm, 300.0 g of propylene oxide were added over a period of 9.93 h.After the addition of this second propylene oxide block, a post-reaction time of 1.0 h followed. Finally, the contents of the autoclave were baked at reaction temperature for 50 minutes under vacuum at approximately 25 mbar. During the cooling phase, 2.533 g of IRGANOX ®< 1076 were added. A clear product was obtained at room temperature with a measured OH number of 391 mg KOH / g and a viscosity of 24,150 mPas at 25 °C. Example 11 (Comparison)

[0120] 835.2 g of a 70% solution of sorbitol in water, 1098.5 g of sucrose, 150.0 g of distilled water, and 10.53 g of imidazole were placed in a 10 l laboratory autoclave under a nitrogen atmosphere. After closing the autoclave, residual oxygen was removed from it by pressurizing it with nitrogen five times to an absolute pressure of 5 bar while the stirrer was running (100 rpm, grid stirrer), followed by depressurization to atmospheric pressure. The reactor was then heated to 110 °C while stirring. During the heating phase, the stirrer speed was increased to 450 rpm (corresponding to a power input of approximately 4.6 W / l, based on the fill level at the end of the metering of all reactants). Under these conditions, 1070.5 g of propylene oxide were initially metered in over a total period of 10.1 h. After the dosing of this first propylene oxide block was completed, a post-reaction time of 2 h followed.The contents of the autoclave were then stripped of water over a period of 3.0 h at 110 °C while stirring at 100 rpm under vacuum at a pressure of approximately 155 mbar, while introducing 50 ml of nitrogen per minute through a distributor ring located below the liquid level. The autoclave was then cooled to 40 °C, and 3137.7 g of soybean oil were added. After closing the autoclave, residual oxygen was removed by pressurizing it five times with nitrogen to an absolute pressure of 5 bar and then depressurizing to atmospheric pressure. The stirrer speed was increased again to 450 rpm, and the reactor contents were heated to 110 °C. Under these conditions, 200.1 g of propylene oxide were metered in over a period of 8.13 h. After the dosing of this second propylene oxide block was completed, a post-reaction time of 0.6 h followed.Finally, the contents of the autoclave were heated at reaction temperature for 90 minutes under vacuum at approximately 32 mbar. During the cooling phase, 2.444 g of IRGANOX ®< 1076 were added. A biphasic product was obtained at room temperature, for which no analytical data could be determined. Example 12 (inventive)

[0121] 835.2 g of a 70% solution of sorbitol in water, 1098.6 g of sucrose, 150.1 g of distilled water, and 10.59 g of imidazole were placed in a 10 l laboratory autoclave under a nitrogen atmosphere. After closing the autoclave, residual oxygen was removed from it by pressurizing it with nitrogen five times to an absolute pressure of 5 bar while the stirrer was running (100 rpm, grid stirrer), followed by depressurization to atmospheric pressure. The reactor was then heated to 110 °C while stirring. During the heating phase, the stirrer speed was increased to 450 rpm (corresponding to a power input of approximately 4.6 W / l, based on the fill level at the end of the metering of all reactants). Under these conditions, 1279.3 g of propylene oxide were initially metered in over a total period of 10.1 h. After the dosing of this first propylene oxide block was completed, a post-reaction time of 1.5 h followed.The contents of the autoclave were then stripped over a period of 3.5 h at 110 °C while stirring at 100 rpm under vacuum at a pressure of approximately 135 mbar while introducing 50 ml of nitrogen per minute through a distributor ring located below the liquid level, thus removing the water. The autoclave was then cooled to 40 °C and 3137.8 g of soybean oil were added. After closing the autoclave, residual oxygen was removed by pressurizing it five times with nitrogen to an absolute pressure of 5 bar and then depressurizing to atmospheric pressure. The stirrer speed was increased again to 450 rpm and the reactor contents were heated to 110 °C. Under these conditions, 200.0 g of propylene oxide were metered in over a period of 8.57 h. After the dosing of this second propylene oxide block was completed, a post-reaction time of 2.3 h followed.Finally, the contents of the autoclave were heated at reaction temperature for 90 minutes under vacuum at approximately 30 mbar. During the cooling phase, 2.444 g of IRGANOX ®< 1076 were added. A product was obtained that was clear at room temperature with a measured OH number of 391 mg KOH / g and a viscosity of 22,750 mPas at 25 °C. Table 1 Example n(1) n(3-1) [mol] t 1 [h] n(2) [mol] n(3-2) [mol] t 2 [h] n(3-2) / n(2) t 2 [h] n(2) / n(3-2) [mol] / [mol] n(3-1) / n(1) [mol] / [mol] Fatty acid ester content [mass%] OH number product (calculated) [mg(KOH) / g] Look 1 44,93 20,3 9,2 10,7 5,17 9,7 4,7 2,07 0,45 49,7 399 Clear, single-phase 2 (cf.) 44,94 20,3 2,7 10,71 5,17 1,2 0,59 2,07 0,45 49,7 399 two-phase 3 (cf.) 44,93 17,22 10 10,7 8,25 10,2 7,89 1,3 0,38 48,9 399 cloudy 4 (cf.) 44,91 17,22 10,2 10,7 8,25 8,2 6,32 1,3 0,38 49,7 399 two-phase 5 (cf.) 44,92 17,22 10,2 10,7 8,25 2 1,54 1,3 0,38 49,7 399 two-phase 6 (cf.) 48,8 18,71 10,2 11,62 13,1 2,2 2,48 0,89 0,38 48 386 Clear, single-phase 7 44,95 22,02 10,1 10,7 3,44 12,1 3,89 3,11 0,49 49,7 400 Clear, single-phase 8 44,93 20,3 10,1 10,7 5,17 8,6 4,16 2,07 0,45 49,7 399 Clear, single-phase 9 (cf.) 44,94 20,3 9,3 10,7 5,17 1,25 0,6 2,07 0,45 49,7 399 two-phase 10 44,99 20,3 10,2 10,7 5,17 9,93 4,8 2,07 0,45 49,7 400 Clear, single-phase 11 (cf.) 44,92 18,43 10,1 10,7 3,45 8,13 2,62 3,1 0,41 51,4 413 two-phase 12 44,92 22,03 10,1 10,7 3,44 8,57 2,83 3,11 0,49 49,7 399 Clear, single-phase (See): Comparative example

Claims

1. Process for preparing a polyoxyalkylene polyester polyol having a calculated OH number of 320 mg KOH / g to 530 mg KOH / g, preferably from 350 mg KOH / g to 500 mg KOH / g, by reacting an H-functional starter compound (1) having n(1) mol of alcoholic hydroxy groups and / or aminic protons, preferably having n(1) mol of alcoholic hydroxy groups, and a fatty acid ester (2) having n(2) mol of fatty acid ester groups with an alkylene oxide (3), optionally in the presence of a basic catalyst (4) and optionally in a solvent (5), wherein the H-functional starter compound (1) comprises one or more compounds, wherein at least one H-functional starter compound (1) has a melting point of > 50.0°C, preferably of > 55.0°C, determined according to the method DIN EN ISO 11357-1:2016, wherein the fatty acid ester (2) has an OH number of less than 100 mg KOH / g, wherein the proportion of the fatty acid ester (2) is at least 40% by mass based on the total mass of the employed H-functional starter compound (1), the employed fatty acid ester (2) and the employed alkylene oxide (3), wherein the process comprises the steps of: (i) providing a system (i) comprising the H-functional starter compound (1) and optionally the basic catalyst (4) optionally in a solvent (5) in a reaction vessel, (ii) adding n(3-1) mol of a first sub-amount of the alkylene oxide (3) to the system (i) over a period t1 to form an intermediate (ii), (iii) removing any solvent (5) present from the intermediate (ii) to form an intermediate (iii), (iv) adding the fatty acid ester (2) to the intermediate (ii) or to the intermediate (iii) to form the intermediate (iv), wherein n(2) mol of fatty acid ester groups are supplied to the intermediate (ii) or the intermediate (iii), (v) adding n(3-2) mol of a second sub-amount of the alkylene oxide (3) to the intermediate (iv) over a period t2 to form the polyoxyalkylene polyester polyol, wherein (n(3-2) / n(2)) • t2 / [h] ≥ 1.0, wherein n(2) / n(3-2) ≥ 1.05, wherein n(3-1) / n(1) ≥ 0.43.

2. Process according to Claim 1, wherein the starter compound (1) has a melting point of more than 65°C, preferably of 65°C to 265°C and particularly preferably of 80°C to 180°C.

3. Process according to Claim 1 or 2, wherein the H-functional starter compound (1) having the melting point of > 50.0°C is one or more compounds selected from the group consisting of trimethylolpropane, pentaerythritol, sorbitol, sucrose, hydroquinone, catechol, resorcinol, bisphenol F, bisphenol A, 1,3,5-trihydroxybenzene, 1,12-dodecanediol, the isomers of diaminotoluene, the isomers of diaminodiphenylmethane, preferably from the group consisting of pentaerythriol, sorbitol and sucrose.

4. Process according to any of Claims 1 to 3, wherein the fatty acid ester (2) is one or more compounds selected from the group consisting of cottonseed oil, peanut oil, coconut oil, linseed oil, palm kernel oil, olive oil, corn oil, palm oil, jatropha oil, rapeseed oil, soybean oil, sunflower oil, herring oil, sardine oil and tallow, preferably soybean oil.

5. Process according to any of Claims 1 to 4, wherein the alkylene oxide (3) is propylene oxide and / or ethylene oxide, preferably propylene oxide.

6. Process according to any of Claims 1 to 5, wherein the reaction in step (i) and / or in step (iv), preferably in step (i), is carried out in the presence of a basic catalyst (4), wherein the basic catalyst is preferably an amine, preferably an aromatic amine.

7. Process according to Claim 6, wherein the amine is an aromatic amine and the aromatic amine is one or more compounds selected from the group consisting of imidazole, 1-methylimidazole, 2-methylimidazole, 4(5)-methylimidazole, 2,4(5)-dimethylimidazole, 1-ethylimidazole, 2-ethylimidazole, 1-phenylimidazole, 2-phenylimidazole, 4(5)-phenylimidazole, and N,N-dimethylaminopyridine.

8. Process according to any of Claims 1 to 7, wherein the proportion of the fatty acid ester (2) is from 40% by mass to 60% by mass, preferably from 42% by mass to 58% by mass and particularly preferably from 45% by mass to 55% by mass.

9. Process according to any of Claims 1 to 8, wherein 1.0 ≤ (n(3-2) / n(2)) • t2 / [h] ≤ 10.0, preferably 1.0 ≤ (n(3-2) / n(2)) • t2 / [h] ≤ 8.0.

10. Process according to any of Claims 1 to 9, wherein 1.05 ≤ n(2) / n(3-2) ≤ 10.0, preferably 1.25 ≤ n(2) / n(3-2) ≤ 6.

11. Process according to any of Claims 1 to 10, wherein 0.43 ≤ n(3-1) / n(1) ≤ 0.92, preferably 0.44 ≤ n(3-1) / n(1) ≤ 0.80.

12. Process according to any of Claims 1 to 11, wherein in step i) the system (i) comprises a solvent (5), wherein the solvent (5) contains water.

13. Polyoxyalkylene polyester polyol obtainable according to any of Claims 1 to 12.

14. Polyoxyalkylene polyester polyol according to Claim 13 having a turbidity number determined by the method specified in the experimental section of ≤ 30 NTUs, preferably of ≤ 20 NTUs.

15. Process for preparing polyurethanes by reacting the polyoxyalkylene polyester polyol according to Claim 13 or 14 with a polyisocyanate.