METHOD FOR THE PRODUCTION OF A POLYOXYALKYLENE POLYESTER POLYOL

Description

[0001] The invention relates to a process for the production of a polyoxyalkylene polyester polyol by reacting a polyoxyalkylene polyol with a lactone in the presence of a Brønsted acid catalyst, wherein the catalyst has a pKa value of 1 or less, wherein the number-average molar mass of the polyoxyalkylene polyol is ≥ 1000 g / mol, preferably ≥ 1500 g / mol, particularly preferably ≥ 2000 g / mol, wherein a CH₂ group is bonded to the ring oxygen in the lactone, and wherein the polyoxyalkylene polyol has a proportion of at least 75% secondary OH end groups based on the sum of primary and secondary OH end groups, wherein the secondary OH end groups have been determined by the 1H-NMR spectroscopy disclosed in the experimental part.Another object is polyoxyalkylene polyester polyols obtainable according to the inventive process as well as a process for the production of polyurethanes by reacting the inventive polyoxyalkylene polyester polyols with polyisocyanates.

[0002] WO2008 / 104723 A1 discloses a process for the production of a polylactone or polylactam, in which the lactone or lactam is reacted with an H-functional starter substance in the presence of a non-chlorinated aromatic solvent and a sulfonic acid on a microliter scale. Low-molecular-weight monofunctional or polyfunctional alcohols or thiols are used as the H-functional starter substance, with n-pentanol, ε-caprolactone, or δ-valerolactone being disclosed in the exemplary embodiments in the presence of high amounts of trifluoromethanesulfonic acid of 2.5 mol% or more.

[0003] In Couffin et al. (Poly. Chem. 2014, 5, 161), a selective O-acyl opening of β-butyrolactone to H-functional initiators such as n-pentanol, 1,4-butanediol, and polyethylene glycol in deuterated benzene and in the presence of trifluoromethanesulfonic acid is disclosed in batch mode. The reactions are carried out on a microliter scale using high amounts of the acid catalyst, 1 mol% or more relative to the amount of lactone used.

[0004] US 5032671 discloses a process for the production of polymeric lactones by reacting an H-functional starter substance and lactones in the presence of a double metal cyanide (DMC) catalyst. In the exemplary embodiments, the reaction of polyether polyols with ε-caprolactone, δ-valerolactone, or β-propiolactone to form polyether-polyester-polyol block copolymers is disclosed. These reactions are carried out in the presence of high amounts of the cobalt-containing DMC catalyst (980 ppm to 1000 ppm) and in the presence of organic solvents. The resulting products exhibit a broad molar mass distribution from 1.32 to 1.72. Furthermore, this process requires a work-up step in which the products are filtered through diatomaceous earth and the solvent is subsequently removed.

[0005] In GB1201909, a process for the production of polyesters by reacting a lactone with an H-functional starter compound in the presence of an organic carboxylic or sulfonic acid whose pKa value at 25 °C is less than 2.0 is also disclosed. In this process, all reaction components, such as short-chain alcohols as well as ε-caprolactone or mixtures of isomeric methyl-epsilon-caprolactones, are placed in high quantities of trichloroacetic or trifluoroacetic acid catalyst and reacted in a batch process for at least 20 h, yielding solid or liquid products.

[0006] WO 2011 / 000560 A1 discloses a process for the production of polyether ester polyols with primary hydroxyl end groups, comprising the steps of reacting a starter compound containing active hydrogen atoms with an epoxide under double metal cyanide catalysis, reacting the resulting product with a cyclic carboxylic anhydride, and reacting this resulting product with ethylene oxide in the presence of a catalyst comprising at least one nitrogen atom per molecule, excluding non-cyclic, identically substituted tertiary amines. The resulting polyether ester polyols of this multi-step process have a primary hydroxyl group content of at most 76%.

[0007] In Hu et al. Biomacromolecules 2004, 5, 1756-1762, a synthesis process for poly(ε-caprolactone)-β-poly(ethylene glycol)-β-poly(ε-caprolactone) triblock copolymers with number-average molar masses of approximately 35,000 g / mol (GPC) is disclosed. This process involves the ring-opening polymerization of ε-caprolactone onto polyethylene glycols as H-functional starter compounds with molar masses of 2,000-10,000 g / mol, which exclusively possess primary hydroxyl end groups, in the presence of a tin octoate catalyst. The reaction of starter compounds with predominantly or exclusively secondary hydroxyl end groups is not described.

[0008] Based on the prior art, the object of the present invention was therefore to provide a simplified, preferably one-step process for the production of long-chain polyoxyalkylene polyester polyols with a number-average molar mass of at least 1200 g / mol and a primary hydroxyl group content of ≥ 80% based on the sum of primary and secondary terminal hydroxyl groups. The resulting polyols should exhibit narrow number-average molar mass distributions with polydispersity indices (PDI) of less than or equal to 1.2. Furthermore, this process should use the smallest possible amounts of a highly reactive, heavy-metal-free catalyst, so that, if possible, no catalyst removal is necessary before further processing.Furthermore, the process according to the invention is also intended to enable the reaction of starter compounds with predominantly or exclusively secondary hydroxyl end groups, resulting in polyoxyalkylene polyester polyols with a number-average molar mass of at least 1200 g / mol and a primary hydroxyl group content of ≥ 80% based on the sum of primary and secondary terminal hydroxyl groups.

[0009] Surprisingly, it was found that the technical problem is solved by a process for the preparation of a polyoxyalkylene polyester polyol by reacting a polyoxyalkylene polyol with a lactone in the presence of a Brønsted acid catalyst; wherein the catalyst has a pKa value of 1 or less, wherein the number-average molar mass of the polyoxyalkylene polyol is ≥ 1000 g / mol, preferably ≥ 1500 g / mol, particularly preferably ≥ 2000 g / mol, wherein a CH₂ group is bonded to the ring oxygen in the lactone, and wherein the polyoxyalkylene polyol has a proportion of at least 75% secondary OH end groups based on the sum of primary and secondary OH end groups, wherein the secondary OH end groups were determined by the 1H-NMR spectroscopy disclosed in the experimental part.

[0010] In the method according to the invention, the number-average molar mass, for example of the polyoxyalkylene polyols and the polyoxyalkylene polyester polyols according to the invention, is determined by means of the gel permeation chromatography (GPC) disclosed in the experimental part. Polyoxyalkylene polyol

[0011] In the process according to the invention, the number-average molar mass of the polyoxyalkylene polyol is ≥ 1000 g / mol, preferably ≥ 1500 g / mol and particularly preferably ≥ 2000 g / mol.

[0012] In the process according to the invention, the number-average molar mass of the polyoxyalkylene polyol is ≤ 30000 g / mol, preferably ≤ 25000 g / mol and particularly preferably ≤ 20000 g / mol.

[0013] In a preferred embodiment of the process according to the invention, the number-average molar mass of the polyoxyalkylene polyol is ≥ 1000 g / mol to ≤ 30000 g / mol, preferably ≥ 1500 g / mol to ≤ 25000 g / mol and particularly preferably ≥ 2000 g / mol to ≤ 20000 g / mol.

[0014] The polyoxyalkylene polyol generally exhibits an OH functionality (i.e., number of hydrogen atoms active for polymerization per molecule) of 2 to 8, preferably 2 to 6, and particularly preferably 2 to 4. The polyoxyalkylene polyol can be used either individually or as a mixture of at least two polyoxyalkylene polyols.

[0015] For example, one or more compounds can be selected as polyoxyalkylene polyols from the group comprising polyether polyols, polyester polyols, polyester ether polyols, polyether carbonate polyols, polycarbonate polyols, polytetrahydrofurans (e.g., PolyTHF®< of BASF, such as PolyTHF®< 1000, 1000S, 1400, 1800, 2000).

[0016] In the process according to the invention, the polyoxyalkylene polyol has a proportion of at least 75% secondary OH end groups based on the sum of primary and secondary OH end groups, wherein the secondary OH end groups have been determined by means of the 1H-NMR spectroscopy disclosed in the experimental part.

[0017] In one embodiment of the invention, the polyoxyalkylene polyols can be selected from the class of polyether polyols. Preferred are polyether polyols composed of repeating ethylene oxide and propylene oxide units, preferably with a proportion of 50 to 100% propylene oxide units, and particularly preferably with a proportion of 80 to 100% propylene oxide units. These can be statistical copolymers, gradient copolymers, alternating copolymers, or block copolymers of ethylene oxide and propylene oxide. Suitable polyether polyols composed of repeating propylene oxide and / or ethylene oxide units include, for example, Desmophen®, Acclaim®, Arcol®, Baycoll®, Bayfill®, Bayflex®, Baygal®, PET®, and polyether polyols from Covestro AG (such as...).Desmophen® < 3600Z, Desmophen® < 1900U, Acclaim® < Polyol 2200, Acclaim® < Polyol 4000I, Arcol® < Polyol 1010, Arcol® < Polyol 1030, Arcol® < Polyol 1070, Baycoll® < BD 1110, Bayfill® < VPPU 0789, Baygal® < K55, Polyether® < S 180). Other suitable homo-polypropylene oxides are, for example, the Pluriol® < P trademarks of BASF SE; suitable mixed copolymers of ethylene oxide and propylene oxide are, for example, the Pluronic® < PE or Pluriol® < RPE trademarks of BASF SE.

[0018] In one embodiment of the invention, the polyoxyalkylene polyols can be selected from the class of polyester polyols, in particular those with a molecular weight Mn in the range of 1000 to 4500 g / mol. At least difunctional polyesters can be used as polyester polyols. Preferably, polyester polyols consist of alternating acid and alcohol units. Examples of acid components include succinic acid, maleic acid, maleic anhydride, adipic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, or mixtures of the aforementioned acids and / or anhydrides. Examples of alcohol components include...Ethanediol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,4-bis(hydroxymethyl)cyclohexane, diethylene glycol, dipropylene glycol, trimethylolpropane, glycerol, pentaerythritol, or mixtures of the aforementioned alcohols are used. If dihydric or polyhydric polyether polyols are used as the alcohol component, polyester ether polyols are obtained, which can also serve as starter substances for the production of polyoxyalkylene polyester polyols. Polyether polyols with Mn = 150 to 2000 g / mol are preferably used for the production of polyester ether polyols.

[0019] In one embodiment of the invention, the polyoxyalkylene polyols can be selected from the class of polycarbonate diols, in particular those with a molecular weight Mn in the range of 1000 to 4500 g / mol, preferably 1500 to 2500 g / mol, which are produced, for example, by reacting phosgene, dimethyl carbonate, diethyl carbonate, or diphenyl carbonate with difunctional alcohols, polyester polyols, or polyether polyols. Examples of polycarbonates can be found, for example, in EP-A 1359177. For example, the Desmophen®< C types from Covestro AG, such as Desmophen®< C 1100 or Desmophen®< C 2200, can be used as polycarbonate diols.

[0020] In a further embodiment of the invention, the polyoxyalkylene polyols can be selected from the class of polyether carbonate polyols (e.g., cardyon® polyols from Covestro), polycarbonate polyols (e.g., Converge® polyols from Novomer / Saudi Aramco, NEOSPOL polyols from Repsol, etc.), and / or polyether ester carbonate polyols. In particular, polyether carbonate polyols, polycarbonate polyols, and / or polyether ester carbonate polyols can be obtained by reacting alkylene oxides, preferably ethylene oxide, propylene oxide, or mixtures thereof, optionally with further co-monomers, with CO₂ in the presence of a hydrogen-functional initiator and using catalysts. These catalysts include double metal cyanide catalysts (DMC catalysts) and / or metal complex catalysts, for example, based on the metals zinc and / or cobalt, such as zinc glutarate catalysts (described, e.g., in MH Chisholm et al.).Macromolecules 2002, 35, 6494), so-called zinc diiminate catalysts (described, for example, in SD Allen, J. Am. Chem. Soc. 2002, 124, 14284) and so-called cobalt salen catalysts (described, for example, in US 7,304,172 B2, US 2012 / 0165549 A1) and / or manganese salen complexes. An overview of known catalysts for the copolymerization of alkylene oxides and CO2 is given, for example, in Chemical Communications 47(2011)141-163. The use of different catalyst systems, reaction conditions, and / or reaction sequences results in the formation of statistical, alternating, block-like, or gradient-like polyether carbonate polyols, polycarbonate polyols, and / or polyether ester carbonate polyols. These polyether carbonate polyols, polycarbonate polyols and / or polyether ester carbonate polyols can be produced beforehand in a separate reaction step.

[0021] In a preferred embodiment of the process according to the invention, the polyoxyalkylene polyol is a polyether polyol and / or polyether carbonate polyol.

[0022] In one embodiment of the process according to the invention, the polyoxyalkylene polyol is a polyether polyol, wherein the polyether polyol has a number-average molar mass ≥ 1000 g / mol, preferably ≥ 1500 g / mol and particularly preferably ≥ 2000 g / mol.

[0023] In one embodiment of the process according to the invention, the polyoxyalkylene polyol is a polyether polyol, wherein the polyether polyol has a number-average molar mass of ≤ 30000 g / mol, preferably ≤ 25000 g / mol and particularly preferably ≤ 20000 g / mol.

[0024] In one embodiment of the process according to the invention, the polyoxyalkylene polyol is a polyether polyol, wherein the polyether polyol has a number-average molar mass of ≥ 1000 g / mol to ≤ 30000 g / mol, preferably ≥ 1500 g / mol to ≤ 25000 g / mol and particularly preferably ≥ 2000 g / mol to ≤ 20000 g / mol.

[0025] In a preferred embodiment of the process according to the invention, the polyoxyalkylene polyol is a polyether polyol, wherein the polyether polyol is produced by reacting an H-functional starter substance with alkylene oxides in the presence of a double metal cyanide catalyst. The products obtained after reaction with the lactone are hereinafter referred to as polyether polyester polyols.

[0026] In one embodiment of the process according to the invention, the polyoxyalkylene polyol is a polyether carbonate polyol, wherein the polyether carbonate polyol has a number-average molar mass ≥ 1000 g / mol, preferably ≥ 1500 g / mol and particularly preferably ≥ 2000 g / mol.

[0027] In one embodiment of the process according to the invention, the polyoxyalkylene polyol is a polyether carbonate polyol, wherein the polyether carbonate polyol has a number-average molar mass of ≤ 30000 g / mol, preferably ≤ 25000 g / mol and particularly preferably ≤ 20000 g / mol.

[0028] In one embodiment of the process according to the invention, the polyoxyalkylene polyol is a polyether carbonate polyol, wherein the polyether carbonate polyol has a number-average molar mass of ≥ 1000 g / mol to ≤ 30000 g / mol, preferably ≥ 1500 g / mol to ≤ 25000 g / mol and particularly preferably ≥ 2000 g / mol to ≤ 20000 g / mol.

[0029] In a further preferred embodiment of the process according to the invention, the polyoxyalkylene polyol is a polyether carbonate polyol, wherein the polyether carbonate polyol is produced by reacting an H-functional starter substance with alkylene oxides and carbon dioxide in the presence of a double metal cyanide catalyst. The products obtained after reaction with the lactone are hereinafter referred to as polyether carbonate polyester polyols. Double metal cyanide (DMC) catalyst

[0030] The DMC catalysts that can preferably be used in the process according to the invention contain double metal cyanide compounds, which are the reaction products of water-soluble metal salts and water-soluble metal cyanide salts.

[0031] Double metal cyanide (DMC) catalysts for use in the homopolymerization of alkylene oxides are known in principle from the prior art (see, e.g., US-A 3,404,109, US-A 3,829,505, US-A 3,941,849, and US-A 5,158,922). DMC catalysts described, e.g., in 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, possess very high activity and enable the production of polyoxyalkylene polyols at very low catalyst concentrations. A typical example is the highly active DMC catalysts described in EP-A 700 949, which, in addition to a double metal cyanide compound (e.g. zinc hexacyanocobaltate(III)) and an organic complex ligand (e.g. tert-butanol), also contain a polyether with a number-mean molecular weight greater than 500 g / mol.

[0032] The DMC catalysts that can be used according to the invention are preferably obtained by (1.) in the first step, reacting an aqueous solution of a metal salt with the aqueous solution of a metal cyanide salt in the presence of one or more organic complex ligands, e.g., an ether or alcohol, (2.) in the second step, separating the solid from the suspension obtained from (1.) by known techniques (such as centrifugation or filtration), (3.) optionally in a third step, washing the isolated solid with an aqueous solution of an organic complex ligand (e.g., by resuspension and subsequent re-isolation by filtration or centrifugation), (4.) subsequently, drying the resulting solid, optionally after pulverization, at temperatures generally of 20–120°C and at pressures generally of 0.1 mbar to atmospheric pressure (1013 mbar). and wherein in the first step or immediately after the precipitation of the In the second step of the double metal cyanide compound, one or more organic complex ligands, preferably in excess (relative to the double metal cyanide compound) and optionally further complex-forming components are added.

[0033] The double metal cyanide compounds contained in the DMC catalysts that can be used according to the invention are the reaction products of water-soluble metal salts and water-soluble metal cyanide salts.

[0034] For example, an aqueous zinc chloride solution (preferably in excess relative to the metal cyanide salt) and potassium hexacyanocobaltate are mixed, followed by dimethoxyethane (Glyme) or tert -Butanol (preferably in excess, based on zinc hexacyanocobaltate) is added to the suspension formed.

[0035] Metal salts suitable for the preparation of the double metal cyanide compounds preferably have a composition according to the general formula (I), M(X) n (I), wherein M is selected from the metal cations Zn 2+< , Fe 2+< , Ni 2+< , Mn 2+< , Co 2+< , Sr 2+< , Sn 2+< , Pb 2+< and, Cu 2+< , preferably M is Zn 2+< , Fe 2+< , Co 2+< or Ni 2+< , X are one or more (i.e. different) anions, preferably an anion selected from the group of halides (i.e. fluoride, chloride, bromide, iodide), hydroxide, sulfate, carbonate, cyanate, thiocyanate, isocyanate, isothiocyanate, carboxylate, oxalate and nitrate; n is 1 if X = sulfate, carbonate or oxalate and n is 2 if X = halide, hydroxide, carboxylate, cyanate, thiocyanate, isocyanate, isothiocyanate or nitrate, or suitable metal salts preferably have a composition according to the general formula (II), M r (X) 3 (II), wherein M is selected from the metal cations Fe 3+< , Al 3+< , Co 3+< and Cr 3+< , X comprises one or more (i.e. different) anions, preferably an anion selected from the group of halides (i.e.Fluoride, chloride, bromide, iodide), hydroxide, sulfate, carbonate, cyanate, thiocyanates, isocyanate, isothiocyanate, carboxylate, oxalate and nitrate; r is 2 if X = sulfate, carbonate or oxalate and r is 1 if X = halide, hydroxide, carboxylate, cyanate, thiocyanate, isocyanate, isothiocyanate or nitrate, or suitable metal salts preferably have a composition according to the general formula (III), M(X) s (III), wherein M is selected from the metal cations Mo 4+< , V 4+< and W 4+< , X comprises one or more (i.e. different) anions, preferably an anion selected from the group of halides (i.e.Fluoride, chloride, bromide, iodide), hydroxide, sulfate, carbonate, cyanate, thiocyanate, isocyanate, isothiocyanate, carboxylate, oxalate and nitrate; s is 2 if X = sulfate, carbonate or oxalate and s is 4 if X = halide, hydroxide, carboxylate, cyanate, thiocyanate, isocyanate, isothiocyanate or nitrate, or suitable metal salts preferably have a composition according to the general formula (IV), M(X) t (IV), wherein M is selected from the metal cations Mo 6+< and W 6+< , X comprises one or more (i.e. different) anions, preferably anions selected from the group of halides (i.e. fluoride, chloride, bromide, iodide), hydroxide, sulfate, carbonate, cyanate, thiocyanate, isocyanate, isothiocyanate, carboxylate, oxalate and nitrate; t is 3 if X = sulfate, carbonate or oxalate and t is 6 if X = halide, hydroxide, carboxylate, cyanate, thiocyanate, isocyanate, isothiocyanate or nitrate.

[0036] Examples of suitable metal salts include zinc chloride, zinc bromide, zinc iodide, zinc acetate, zinc acetylacetonate, zinc benzoate, zinc nitrate, iron(II) sulfate, iron(II) bromide, iron(II) chloride, iron(III) chloride, cobalt(II) chloride, cobalt(II) thiocyanate, nickel(II) chloride, and nickel(II) nitrate. Mixtures of different metal salts can also be used.

[0037] Metal cyanide salts suitable for the preparation of the double metal cyanide compounds preferably have a composition according to the general formula (V) (Y) a M'(CN) b (A) c (V), wherein M' is selected from one or more metal cations of the group consisting of Fe(II), Fe(III), Co(II), Co(III), Cr(II), Cr(III), Mn(II), Mn(III), Ir(III), Ni(II), Rh(III), Ru(II), V(IV) and V(V); preferably, M' is one or more metal cations of the group consisting of Co(II), Co(III), Fe(II), Fe(III), Cr(III), Ir(III) and Ni(II); Y is selected from one or more metal cations of the group consisting of alkali metal (i.e., Li< , Na< , K< , Rb< ) and alkaline earth metal (i.e., Be 2< , Mg 2< , Ca 2< , Sr 2< , Ba 2< ); A is selected from one or more anions of the group consisting of halides (i.e.,Fluoride, chloride, bromide, iodide), hydroxide, sulfate, carbonate, cyanate, thiocyanate, isocyanate, isothiocyanate, carboxylate, azide, oxalate or nitrate, and a, b and c are integers, wherein the values ​​for a, b and c are chosen such that the electroneutrality of the metal cyanide salt is given; a is preferably 1, 2, 3 or 4; b is preferably 4, 5 or 6; c preferably has the value 0.

[0038] Examples of suitable metal cyanide salts are sodium hexacyanocobaltate(III), potassium hexacyanocobaltate(III), potassium hexacyanoferrate(II), potassium hexacyanoferrate(III), calcium hexacyanocobaltate(III) and lithium hexacyanocobaltate(III).

[0039] Preferred double metal cyanide compounds contained in the DMC catalysts usable according to the invention are compounds with compositions according to the general formula (VI) M x [M' x ,(CN) y ] z (VI), wherein M is defined as in formulas (I) to (IV) and M' as in formula (V), and x, x', y and z are integers and chosen such that the electron neutrality of the double metal cyanide compound is given.

[0040] Preferably x = 3, x' = 1, y = 6 and z = 2, M = Zn(II), Fe(II), Co(II) or Ni(II) and M' = Co(III), Fe(III), Cr(III) or Ir(III).

[0041] Examples of suitable double metal cyanide compounds (VI) are zinc hexacyanocobaltate(III), zinc hexacyanoiridate(III), zinc hexacyanoferrate(III), and cobalt(II) hexacyanocobaltate(III). Further examples of suitable double metal cyanide compounds can be found, for example, in US 5,158,922 (column 8, lines 29-66). Zinc hexacyanocobaltate(III) is particularly preferred.

[0042] The organic complex ligands that can be added in the production of DMC catalysts are disclosed, for example, in US-A 5,158,922 (see especially column 6, lines 9 to 65), US 3,404,109, US 3,829,505, US 3,941,849, EP-A 700,949, EP-A 761,708, JP 4,145,123, US 5,470,813, EP-A 743,093, and WO-A 97 / 40086. For example, water-soluble organic compounds with heteroatoms, such as oxygen, nitrogen, phosphorus, or sulfur, which can form complexes with the double metal cyanide compound, are used as organic complex ligands. Preferred organic complex ligands are alcohols, aldehydes, ketones, ethers, esters, amides, ureas, nitriles, sulfides, and mixtures thereof. Particularly preferred organic complex ligands are aliphatic ethers (such as dimethoxyethane), water-soluble aliphatic alcohols (such as ethanol, isopropanol, n-butanol, isobutanol, sec.-Butanol, tert-butanol, 2-methyl-3-buten-2-ol, and 2-methyl-3-butyn-2-ol), compounds containing both aliphatic or cycloaliphatic ether groups and aliphatic hydroxyl groups (such as ethylene glycol mono-tert-butyl ether, diethylene glycol mono-tert-butyl ether, tripropylene glycol mono-methyl ether, and 3-methyl-3-oxetan-methanol). Highly preferred organic complex ligands are selected from one or more compounds of the group consisting of dimethoxyethane, tert-butanol, 2-methyl-3-buten-2-ol, 2-methyl-3-butyn-2-ol, ethylene glycol mono-tert-butyl ether, and 3-methyl-3-oxetan-methanol.

[0043] Optionally, in the production of the DMC catalysts usable according to the invention, one or more complexing components are used from the following classes of compounds: polyethers, polyesters, polycarbonates, polyalkylene glycol sorbitan esters, polyalkylene glycol glycidyl ethers, polyacrylamide, poly(acrylamide-co-acrylic acid), polyacrylic acid, poly(acrylic acid-co-maleic acid), polyacrylonitrile, polyalkyl acrylates, polyalkyl methacrylates, polyvinyl methyl ethers, polyvinyl ethyl ethers, polyvinyl acetate, polyvinyl alcohol, poly-N-vinylpyrrolidone, poly(N-vinylpyrrolidone-co-acrylic acid), polyvinyl methyl ketone, poly(4-vinylphenol), poly(acrylic acid-co-styrene), oxazoline polymers, polyalkyleneimines, maleic acid and maleic anhydride copolymers, hydroxyethylcellulose and polyacetals, or glycidyl ethers, glycosides, carboxylic acid esters of polyhydric alcohols, bile acids or their salts, esters or Amides, cyclodextrins, phosphorus compounds, α,β-unsaturated carboxylic acid esters or ionic surface orsurface-active compounds are used.

[0044] Preferably, in the preparation of the DMC catalysts usable according to the invention, the aqueous solutions of the metal salt (e.g., zinc chloride) are used in the first step in a stoichiometric excess (at least 50 mol%) relative to the metal cyanide salt. This corresponds to a minimum molar ratio of metal salt to metal cyanide salt of 2.25 to 1.00. The metal cyanide salt (e.g., potassium hexacyanocobaltate) is reacted in the presence of the organic complex ligand (e.g., tert-butanol), forming a suspension containing the double metal cyanide compound (e.g., zinc hexacyanocobaltate), water, excess metal salt, and the organic complex ligand.

[0045] The organic complexing ligand can be present in the aqueous solution of the metal salt and / or the metal cyanide salt, or it can be added directly to the suspension obtained after precipitation of the double metal cyanide compound. It has proven advantageous to mix the aqueous solutions of the metal salt and the metal cyanide salt, and the organic complexing ligand, with vigorous stirring. Optionally, the suspension formed in the first step is subsequently treated with a further complexing component. The complexing component is preferably used in a mixture with water and the organic complexing ligand. A preferred method for carrying out the first step (i.e., the preparation of the suspension) is performed using a mixing nozzle, particularly preferably using a jet disperser, as described, for example, in WO-A 01 / 39883.

[0046] In the second step, the isolation of the solid (i.e., the precursor of the catalyst) from the suspension can be carried out using known techniques such as centrifugation or filtration.

[0047] In a preferred embodiment, the isolated solid is subsequently washed in a third process step with an aqueous solution of the organic complex ligand (e.g., by resuspension and subsequent re-isolation by filtration or centrifugation). In this way, for example, water-soluble byproducts such as potassium chloride can be removed from the catalyst usable according to the invention. Preferably, the amount of the organic complex ligand in the aqueous wash solution is between 40 and 80 wt%, based on the total solution.

[0048] Optionally, in the third step, a further complexing component, preferably in the range between 0.5 and 5 wt.%, based on the total solution, is added to the aqueous washing solution.

[0049] Furthermore, it is advantageous to wash the isolated solid more than once. Preferably, in a first washing step (3.-1), washing is carried out with an aqueous solution of the organic complex ligand (e.g., by resuspension and subsequent re-isolation by filtration or centrifugation) in order to remove, for example, water-soluble byproducts such as potassium chloride from the catalyst usable according to the invention. The amount of the organic complex ligand in the aqueous washing solution is particularly preferably between 40 and 80 wt.%, based on the total solution of the first washing step. In the further washing steps (3.-2), either the first washing step is repeated once or several times, preferably one to three times, or preferably a non-aqueous solution, such as a mixture or solution of organic complex ligands and another complex-forming component (preferably in the range between 0.5 and 5 wt.%), is added.-%, based on the total amount of the washing solution of step (3.-2)), is used as a washing solution and the solid is washed with it once or several times, preferably once to three times.

[0050] The isolated and, if necessary, washed solid can then be dried, if necessary after pulverization, at temperatures of 20 - 100°C and at pressures of 0.1 mbar to normal pressure (1013 mbar).

[0051] A preferred method for isolating the DMC catalysts usable according to the invention from the suspension by filtration, filter cake washing and drying is described in WO-A 01 / 80994. H-functional starter substance

[0052] Suitable hydrogen-functional initiators (starters) can be compounds containing hydrogen atoms active for alkoxylation. Examples of groups active for alkoxylation with active hydrogen atoms are -OH, -SH, and -COzH; -OH is preferred. One or more compounds can be selected as hydrogen-functional initiators from the group comprising polyhydric alcohols, polyhydric thiols, thioalcohols, hydroxy esters, polyether polyols, polyester polyols, polyester ether polyols, polyether carbonate polyols, polycarbonate polyols, and polycarbonates.

[0053] Examples of polyhydric alcohols suitable as H-functional starter substances are dihydric alcohols (such as ethylene glycol, diethylene glycol, 1,2-propylene glycol, dipropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,4-butenediol, 1,4-butynediol, neopentyl glycol, 1,5-pentantanediol, methylpentanediols (such as 3-methyl-1,5-pentanediol), 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, bis-(hydroxymethyl)cyclohexanes (such as 1,4-bis-(hydroxymethyl)cyclohexane), triethylene glycol, tetraethylene glycol, polyethylene glycols, dipropylene glycol, tripropylene glycol, polypropylene glycols, dibutylene glycol and polybutylene glycols); Trihydric alcohols (such as trimethylolpropane, glycerin, trishydroxyethyl isocyanurate, castor oil); tetrahydric alcohols (such as pentaerythritol);Polyalcohols (such as sorbitol, hexitol, sucrose, starch, starch hydrolysates, cellulose, cellulose hydrolysates, hydroxy-functionalized fats and oils, especially castor oil), as well as all modification products of these aforementioned alcohols with varying amounts of ε-caprolactone.;

[0054] The H-functional starter substances can also be selected from the class of polyether polyols, in particular those with a molecular weight Mn in the range of 100 to 1000 g / mol. Polyether polyols composed of repeating ethylene oxide and propylene oxide units are preferred, preferably with a proportion of 35 to 100% propylene oxide units, and particularly preferably with a proportion of 50 to 100% propylene oxide units. These can be statistical copolymers, gradient copolymers, alternating copolymers, or block copolymers of ethylene oxide and propylene oxide. Suitable polyether polyols, composed of repeating propylene oxide and / or ethylene oxide units, include, for example, Desmophen ®< -, Acclaim ®< -, Arcol ®< -, Baycoll ®< -, Bayfill ®< -, Bayflex ®< - Baygal ®< -, PET ®< - and polyether polyols from Covestro AG (PET ®< 1004, PET ®< 1110N).Other suitable homo-polypropylene oxides include, for example, the Pluriol®<P trademarks of BASF SE; suitable mixed copolymers of ethylene oxide and propylene oxide include, for example, the Pluronic®<PE or Pluriol®<RPE trademarks of BASF SE.

[0055] The H-functional starter substances can also be selected from the class of polyester polyols, particularly those with a molecular weight Mn in the range of 200 to 1000 g / mol. At least difunctional polyesters can be used as polyester polyols. Preferably, polyester polyols consist of alternating acid and alcohol units. Examples of acid components include succinic acid, maleic acid, maleic anhydride, adipic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, or mixtures of the aforementioned acids and / or anhydrides. Examples of alcohol components used include ethanediol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,4-bis-(hydroxymethyl)-cyclohexane, diethylene glycol, dipropylene glycol, trimethylolpropane, glycerin, pentaerythritol or mixtures of the aforementioned alcohols.

[0056] Furthermore, polycarbonate diols can be used as H-functional starter substances, in particular those with a molecular weight Mn in the range of 150 to 1000 g / mol, which are produced, for example, by reacting phosgene, dimethyl carbonate, diethyl carbonate, or diphenyl carbonate with difunctional alcohols, polyester polyols, or polyether polyols. Examples of polycarbonates can be found, for example, in EP-A 1359177. For example, the Desmophen®< C types from Covestro AG can be used as polycarbonate diols. In a further embodiment of the invention, polyether carbonate polyols and / or polyether ester carbonate polyols can be used as H-functional starter substances.

[0057] The H-functional starter substances generally exhibit an OH functionality (i.e., number of H atoms active for polymerization per molecule) of 2 to 8, preferably 2 to 6, and particularly preferably 2 to 4. The H-functional starter substances are used either individually or as a mixture of at least two H-functional starter substances.

[0058] Preferred H-functional starter substances are ethylene glycol, propylene glycol, diethylene glycol, trimethylolpropane, glycerol, sorbitol, polyether polyols and polyether carbonate polyols.

[0059] In a preferred embodiment of the process according to the invention, the alkylene oxide is ethylene oxide and / or propylene oxide.

[0060] In a preferred embodiment of the process according to the invention, the weight fraction of the propylene oxide is 80 wt.% to 100 wt.% based on the sum of the dosed masses of the propylene oxide and the ethylene oxide. Lactone

[0061] According to the generally accepted technical understanding in organic chemistry, lactones are heterocyclic compounds formed by intramolecular esterification, i.e., the reaction of a hydroxyl functionality with a carboxy functionality of a hydroxycarboxylic acid. They are therefore cyclic esters with a ring oxygen.

[0062] In the process according to the invention, a CH 2 group is bound to the ring oxygen in the lactone.

[0063] In a preferred embodiment of the method according to the invention, the lactone is one or more compounds and is selected from the group consisting of beta-propiolactone, gamma-butyrolactone, delta-valerolactone and epsilon-caprolactone.

[0064] In a particularly preferred embodiment of the method according to the invention, the lactone is beta-propiolactone.

[0065] In a preferred embodiment of the process according to the invention, the molar ratio between the lactone and the hydroxy end groups of the polyoxyalkylene polyol is 1:1 to 20:1, preferably 1.5:1 to 10:1 and particularly preferably 2:1 to 6:1. Brønsted acid catalyst

[0066] According to the common, technical definition, Brønsted acids are substances that can transfer protons to a second reaction partner, the so-called Brønsted base. For the purposes of the present invention, the term Brønsted acid catalyst refers to a non-polymeric compound, wherein the Brønsted acid catalyst has a calculated molar mass of ≤ 1200 g / mol, preferably ≤ 1000 g / mol, and particularly preferably ≤ 850 g / mol.

[0067] In the process according to the invention, the Brønsted acid catalyst has a pKa value of 1 or less, preferably less than or equal to zero.

[0068] The Brønsted acid catalyst is, for example, selected from one or more compounds of the group consisting of aliphatic fluorinated sulfonic acids, aromatic fluorinated sulfonic acids, trifluoromethanesulfonic acid, perchloric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, fluorosulfonic acid, bis(trifluoromethane)sulfonimide, hexafluoroantimonic acid, pentacyanocyclopentadiene, picric acid, sulfuric acid, nitric acid, trifluoroacetic acid, trichloroacetic acid, methanesulfonic acid, paratoluenesulfonic acid, aromatic sulfonic acids and aliphatic sulfonic acids.

[0069] In a preferred embodiment of the process according to the invention, the Brønsted acid catalyst is one or more compounds selected from the group consisting of trifluoromethanesulfonic acid, perchloric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, nitric acid, methanesulfonic acid, trichloroacetic acid, and trifluoroacetic acid. Trifluoromethanesulfonic acid is particularly preferred as the Brønsted acid catalyst.

[0070] In one embodiment of the process according to the invention, the Brönsted acid catalyst is used in an amount of 0.001 mol% to 0.5 mol%, preferably 0.003 to 0.4 mol% and particularly preferably 0.005 to 0.3 mol% based on the amount of lactone. solvent

[0071] According to the common, technical definition, a solvent is understood to be one or more compounds that dissolve the lactone or the polyoxyalkylene polyol and / or the Brønsted acid catalyst without reacting with the lactone, the polyoxyalkylene polyol and / or the Brønsted acid catalyst itself.

[0072] In one embodiment, the process according to the invention is carried out without the addition of a solvent, so that this does not have to be separated in an additional process step after the production of the polyoxyalkylene polyester polyol.

[0073] In one embodiment of the process according to the invention, the reaction of the polyoxyalkylene polyol with the lactone is carried out in the presence of the Brønsted acid catalyst at temperatures of 20 to 160°C, preferably of 40 to 120°C and particularly preferably of 50 to 110°C.

[0074] InIn one embodiment of the process according to the invention, the lactone is added continuously or stepwise to the mixture of polyoxyalkylene polyol and Brønsted acid catalyst and converted to polyoxyalkylene polyester polyol (semi-batch mode).

[0075] In the process according to the invention, a continuous addition of the lactone is understood to mean a volume flow rate of the lactone of > 0 mL / min, wherein the volume flow rate can be constant or vary during this step (continuous lactone addition).

[0076] In an alternative embodiment of the process according to the invention, the lactone is added stepwise to the mixture of polyoxyalkylene polyol and Brønsted acid catalyst and subsequently converted to the polyoxyalkylene polyester polyol (stepwise lactone addition).

[0077] In the process according to the invention, a stepwise addition of the lactone is understood to mean at least the addition of the total amount of lactone in two or more discrete portions of the lactone, wherein the volume flow rate of the lactone between the two or more discrete portions is 0 mL / min and wherein the volume flow rate of the lactone during a discrete portion may be constant or vary, but is > 0 mL / min.

[0078] In an alternative embodiment, the polyoxyalkylene polyol, the lactone and the Brønsted acid catalyst are mixed and then the entire mixture is reacted to form the polyoxyalkylene polyester polyol (batch mode).

[0079] In another, alternative embodiment, the polyoxyalkylene polyol, the lactone and the Brønsted acid catalyst are continuously mixed and reacted together, while the polyoxyalkylene polyester polyol product is continuously removed, for example in a tubular reactor or a continuous stirred tank reactor, which corresponds to a fully continuous manufacturing process for the polyoxyalkylene polyester polyol (conti-mode).

[0080] Another object of the present invention is polyoxyalkylene polyester polyols, preferably polyether polyester polyol and / or polyether carbonate polyester polyol obtainable according to the inventive method, wherein the polyoxyalkylene polyester polyol has a proportion of at least 80% primary OH end groups based on the sum of primary and secondary OH end groups, wherein the primary OH end groups have been determined by means of the < H or < 13 C NMR spectroscopy disclosed in the experimental part.

[0081] In one embodiment, the polyoxyalkylene polyester polyol according to the invention, preferably polyether polyester polyol and / or polyether carbonate polyester polyol, has a polydispersity index of ≤1.20, preferably ≤1.15, wherein the polydispersity index was determined by the gel permeation chromatography disclosed in the description.

[0082] Another object of the present invention is a process for producing a polyurethane by reacting the polyoxyalkylene polyester polyol according to the invention, preferably the polyether polyester polyol and / or the polyether carbonate polyester polyol with a polyisocyanate.

[0083] The polyisocyanate can be an aliphatic or aromatic polyisocyanate. Examples include 1,4-butylene diisocyanate, 1,5-pentane diisocyanate, 1,6-hexamethylene diisocyanate (HDI) or their dimers, trimers, pentamers, heptamers or nonamers or mixtures thereof, isophorone diisocyanate (IPDI), 2,2,4- and / or 2,4,4-trimethylhexamethylene diisocyanate, the isomeric bis(4,4'-isocyanatocyclohexyl)methanes or mixtures thereof of any isomer content, 1,4-cyclohexylene diisocyanate, 1,4-phenylene diisocyanate, 2,4- and / or 2,6-toluene diisocyanate (TDI), 1,5-naphthylene diisocyanate, 2,2'- and / or 2,4'- and / or 4,4'-diphenylmethane diisocyanate (MDI) and / or higher homologs (polymeric MDI). 1,3- and / or 1,4-bis-(2-isocyanato-prop-2-yl)benzene (TMXDI), 1,3-bis-(isocyanatomethyl)benzene (XDI), and alkyl-2,6-diisocyanatohexanoates (lys diisocyanates) with C1 to C6 alkyl groups.

[0084] In addition to the polyisocyanates mentioned above, modified diisocyanates with uretdione, isocyanurate, urethane, carbodiimide, uretonimine, allophane, biuret, amide, iminooxadiazindione and / or oxadiazinetrione structures, as well as non-modified polyisocyanate with more than 2 NCO groups per molecule, such as 4-isocyanatomethyl-1,8-octanediisocyanate (nonane triisocyanate) or triphenylmethane-4,4',4"-triisocyanate, can also be used in proportion. Examples

[0085] The present invention will be explained in more detail with reference to the following figures and examples, without, however, being limited thereto. Raw materials used cyclic lactones

[0086] β-Propiolactone (purity < 98%, Acros Organics BVBA) ε-Caprolactone (purity < 97%, Sigma-Aldrich) catalysts

[0087] Trifluoromethanesulfonic acid (purity < 99%, Acros Organics) DMC - catalyst prepared according to Example 6 in WO 01 / 80994 A1 Tin(II)-2-ethylhexanoate (purity 92.5 - 100%, Sigma-Aldrich) Polyoxyalkylene polyol (polyether polyol)

[0088] The polyether polyol A was produced by DMC catalysis as follows: In a 20 L pressure reactor, 1739.3 g of a poly(oxypropylene)triol with an OH number of 233 mg KOH / g and 0.367 g of DMC catalyst (prepared according to Example 6 in WO 01 / 80994 A1) were placed under nitrogen. The reactor was heated to 130°C, inertized by three evacuations to 100 mbar (absolute) and repeated exposure to nitrogen, and then stripped for 30 min at 100 mbar and 130°C with nitrogen purging. Subsequently, a mixture of 9256 g of propylene oxide and 1028 g of ethylene oxide was added over three hours at 130°C. After a post-reaction time at 130°C until pressure in the reactor stabilized, volatile components were distilled off at 90°C for 30 min under vacuum and the reaction mixture was then cooled to room temperature.The OH number of the product was 34.3 mg KOH / g, the number mean M n of the molecular weight was 6665 g / mol, the polydispersity was 1.03 and the proportion of primary hydroxy end groups was 18%. Description of the methods: Gel permeation chromatography (GPC):

[0089] The number-mean Mn and weight-mean Mw of the molecular weight, as well as the polydispersity (Mw / Mn) of the products, were determined by gel permeation chromatography (GPC). The procedure followed DIN 55672-1: "Gel permeation chromatography, Part 1 - Tetrahydrofuran as eluent" (SECurity GPC system from PSS Polymer Service, flow rate 1.0 ml / min; columns: 2 x PSS SDV linear M, 8 x 300 mm, 5 µm; RID detector). Polystyrene samples of known molar mass were used for calibration. 1 < Dog 13< C-NMR spectroscopy

[0090] Determination of the molar fraction of primary OH groups: using 1< H- (Bruker AV III HD 600, 600 MHz, deuterochloroform) or 13< C-NMR (Bruker AV III HD 600, 151 MHz, deuterochloroform): To determine the content of primary OH groups, the polyol samples were first peracetylated.

[0091] The following peracetylation mixture was prepared: 9.4 g acetic anhydride pA 1.6 g acetic acid pA 100 mL pyridine pA

[0092] For the peracetylation reaction, 10 g of polyol (polyoxyalkylene polyol or polyoxyalkylene polyester polyol) were weighed into a 300 mL ground-glass lenmeyer flask. The volume of peracetylation mixture depended on the OH number of the polyol to be peracetylated, whereby (based on 10 g of polyol) the OH number of the polyol was rounded up to the nearest ten. For every 10 mg KOH / g, 10 mL of peracetylation mixture was added. For example, 50 mL of peracetylation mixture was added to a 10 g sample of a polyol with an OH number of 45.1 mg KOH / g.

[0093] After adding glass boiling beads, the ground-glass flask was fitted with a riser tube (air condenser), and the sample was boiled for 75 minutes at gentle reflux. The sample mixture was then transferred to a 500 mL round-bottom flask, and volatile components (mainly pyridine, acetic acid, and excess acetic anhydride) were distilled off over 30 minutes at 80°C and 10 mbar (absolute). The distillation residue was then reacted three times with 100 mL of cyclohexane (alternatively, toluene was used in cases where the distillation residue did not dissolve in cyclohexane), and volatile components were removed from the sample for one hour at 100°C and 10 mbar (absolute).

[0094] To determine the molar fractions of primary and secondary OH end groups in the polyol, the prepared sample was dissolved in deuterated chloroform and analyzed by 1H NMR (Bruker AV III HD 600, 600 MHz) or 13C NMR (Bruker AV III HD 600, 151 MHz). The relevant 1H NMR resonances (referenced to TMS = 0 ppm) are as follows: Methyl signal of a peracetylated secondary OH end group: 2.04 ppm Methyl signal of a peracetylated primary OH end group: 2.07 ppm The molar fraction of the secondary and primary OH end groups is then as follows: Anteil sekundärer OH − Endgruppen CH − OH = F 2.04 / F 2.04 + F 2.07 * 100 % Anteil primärer OH − Endgruppen CH 2 − OH = F 2.07 / F 2.04 + F 2.07 * 100 %

[0095] In formulas (VII) and (VIII), F represents the area of ​​resonance at 2.04 ppm and 2.07 ppm, respectively.

[0096] The relevant resonances in 13< C-NMR (referenced to TMS = 0 ppm) are as follows: Methyl signal of a peracetylated secondary OH end group: 21.3 ppm; Methyl signal of a peracetylated primary OH end group: 20.8 ppm

[0097] The molar fraction of the secondary and primary OH end groups is then calculated as follows: Anteil sekundärer OH − Endgruppen CH − OH = F 21.3 / F 21.3 + F 20.8 * 100 % Anteil primärer OH − Endgruppen CH 2 − OH = F 20.8 / F 21.3 + F 20.8 * 100 %

[0098] In formulas (IX) and (X), F represents the area of ​​resonance at 21.3 ppm and 20.8 ppm, respectively. Infrared spectroscopy

[0099] The percentage of lactone conversion relative to the amount of lactone used was determined by IR spectroscopy. For this purpose, the product carbonyl band was examined (1740 cm⁻¹). The reference was the product carbonyl band of a sample with the same molar lactone / hydroxy end group ratio in which no characteristic lactone-starting group bands (e.g., beta-propiolactone starting group carbonyl bands 1802 cm⁻¹, 1824 cm⁻¹) were observed, and whose lactone conversion was therefore set to 100%.

[0100] The percentage of lactone turnover is then calculated as follows: X Lacton % = F 1740 / F ref 1740 * 100 %

[0101] In formula (XI) F represents the area of ​​the product carbonyl band at 1740 cm -1< and F ref represents the area of ​​the product carbonyl band at 1740 cm -1< of a reference sample with the same lactone / hydroxy end group ratio and complete lactone conversion. OH numbers

[0102] The OH numbers were determined according to the DIN 53240 standard. Example 1:

[0103] In a 2-liter stainless steel reactor, 170 g of polyether polyol A were placed and heated to 130°C. The reactor was inertized by three evacuations to 100 mbar (absolute) and repeated purging with nitrogen, and then stripped for 30 min at 100 mbar and 130°C with nitrogen purging. Subsequently, the reactor was cooled to 60°C and a pressure of 1 bar (absolute) was established using nitrogen. At 60°C, a mixture of 10 g of polyether polyol A and 0.03 g of trifluoromethanesulfonic acid (0.08 mol% based on the total amount of lactone used) was added, followed by 5 g of beta-propiolactone. The reaction mixture was stirred for 2 hours at 60°C. Subsequently, beta-propiolactone was added in portions of 5 g (or last portion: 5.9 g) at 15-minute intervals (total amount of beta-propiolactone: 15.9 g; molar ratio of lactone / hydroxy end groups of polyether polyol A: 2 / 1).After complete addition of lactone, the reaction mixture was stirred for 30 min at 60°C and then cooled to room temperature. A lactone conversion of 80% was determined by IR spectroscopy. The number-average molecular weight Mn of the product is 7424 g / mol, the polydispersity is 1.11, and the proportion of primary hydroxyl end groups is 85%. Example 2:

[0104] In a 2-liter stainless steel reactor, 170 g of polyether polyol A were placed and heated to 130°C. The reactor was inertized by three evacuations to 100 mbar (absolute) and repeated purging with nitrogen, and then stripped for 30 min at 100 mbar and 130°C with nitrogen purging. Subsequently, the reactor was cooled to 60°C and a pressure of 1 bar (absolute) was established using nitrogen. At 60°C, a mixture of 10 g of polyether polyol A and 0.04 g of trifluoromethanesulfonic acid (0.08 mol% based on the total amount of lactone used) was added, followed by 5 g of beta-propiolactone. The reaction mixture was stirred for 2 hours at 60°C. Subsequently, beta-propiolactone was added in portions of 5 g (or last portion: 6.2 g) at 15-minute intervals (total amount of beta-propiolactone: 26.2 g; molar ratio of lactone / hydroxy end groups of polyether polyol A: 3.3 / 1).After complete addition of lactone, the reaction mixture was stirred for 30 min at 60°C and then cooled to room temperature. A lactone conversion of 95% was determined by IR spectroscopy. The number-average molecular weight Mn of the product is 7782 g / mol, the polydispersity is 1.10, and the proportion of primary hydroxyl end groups is 89%. Example 3:

[0105] In a 2-liter stainless steel reactor, 170 g of polyether polyol A were placed and heated to 130°C. The reactor was inertized by three evacuations to 100 mbar (absolute) and repeated purging with nitrogen, and then stripped for 30 min at 100 mbar and 130°C with nitrogen purging. Subsequently, the reactor was cooled to 60°C and a pressure of 1 bar (absolute) was established using nitrogen. At 60°C, a mixture of 10 g of polyether polyol A and 0.05 g of trifluoromethanesulfonic acid (0.08 mol% based on the total amount of lactone used) was added, followed by 5 g of beta-propiolactone. The reaction mixture was stirred for 2 hours at 60°C. Subsequently, beta-propiolactone was added in portions of 5 g (or last portion: 6.7 g) at 15-minute intervals (total amount of beta-propiolactone: 31.7 g; molar ratio of lactone / hydroxy end groups of polyether polyol A: 4 / 1).After complete addition of lactone, the reaction mixture was stirred for 30 min at 60°C and then cooled to room temperature. A lactone conversion of 100% was determined by IR spectroscopy. The number-average molecular weight Mn of the product is 8071 g / mol, the polydispersity is 1.11, and the proportion of primary hydroxyl end groups is 96%. Example 4:

[0106] In a 2-liter stainless steel reactor, 170 g of polyether polyol A were placed and heated to 130°C. The reactor was inertized by three evacuations to 100 mbar (absolute) and repeated purging with nitrogen, and then stripped for 30 min at 100 mbar and 130°C with nitrogen purging. Subsequently, the reactor was cooled to 60°C and a pressure of 1 bar (absolute) was established using nitrogen. At 60°C, a mixture of 10 g of polyether polyol A and 0.05 g of trifluoromethanesulfonic acid (0.08 mol% based on the total amount of lactone used) was added, followed by 5 g of beta-propiolactone. The reaction mixture was stirred for 2 hours at 60°C. Subsequently, beta-propiolactone was added in portions of 5 g (or last portion: 6.7 g) at intervals of 1 hour (total amount of beta-propiolactone: 31.7 g; molar ratio of lactone / hydroxy end groups of polyether polyol A: 4 / 1).After complete addition of lactone, the reaction mixture was stirred for 30 min at 60°C and then cooled to room temperature. A lactone conversion of 100% was determined by IR spectroscopy. The number-average molecular weight Mn of the product is 8083 g / mol, the polydispersity is 1.10, and the proportion of primary hydroxyl end groups is 82%. Example 5:

[0107] In a 2-liter stainless steel reactor, 170 g of polyether polyol A were placed and heated to 130°C. The reactor was inertized by three evacuations to 100 mbar (absolute) and repeated purging with nitrogen, and then stripped for 30 min at 100 mbar and 130°C with nitrogen purging. Subsequently, the reactor was cooled to 60°C and a pressure of 1 bar (absolute) was established using nitrogen. At 60°C, a mixture of 10 g of polyether polyol A and 0.17 g of trifluoromethanesulfonic acid (0.25 mol% based on the total amount of lactone used) was added, followed by 5 g of beta-propiolactone. The reaction mixture was stirred for 2 hours at 60°C. Subsequently, beta-propiolactone was added in portions of 5 g (or last portion: 6.7 g) at intervals of 1 hour (total amount of beta-propiolactone: 31.7 g; molar ratio of lactone / hydroxy end groups of polyether polyol A: 4 / 1).After complete addition of lactone, the reaction mixture was stirred for 30 min at 60°C and then cooled to room temperature. A lactone conversion of 100% was determined by IR spectroscopy. The number-average molecular weight Mn of the product is 7696 g / mol, the polydispersity is 1.05, and the proportion of primary hydroxyl end groups is 93%. Example 6:

[0108] In a 2-liter stainless steel reactor, 170 g of polyether polyol A were placed and heated to 130°C. The reactor was inertized by three evacuations to 100 mbar (absolute) and repeated purging with nitrogen, and then stripped for 30 min at 100 mbar and 130°C with nitrogen purging. Subsequently, the reactor was cooled to 100°C and a pressure of 1 bar (absolute) was established using nitrogen. At 100°C, a mixture of 10 g of polyether polyol A and 0.05 g of trifluoromethanesulfonic acid (0.08 mol% based on the total amount of lactone used) was added, followed by 5 g of beta-propiolactone. The reaction mixture was stirred for 2 hours at 100°C. Subsequently, beta-propiolactone was added in portions of 5 g (or last portion: 6.7 g) at 15-minute intervals (total amount of beta-propiolactone: 31.7 g; molar ratio of lactone / hydroxy end groups of polyether polyol A: 4 / 1).After complete addition of lactone, the reaction mixture was stirred for 30 min at 100°C and then cooled to room temperature. A lactone conversion of 100% was determined by IR spectroscopy. The number-average molecular weight Mn of the product is 8374 g / mol, the polydispersity is 1.14, and the proportion of primary hydroxyl end groups is 85%. Example 7:

[0109] In a 2-liter stainless steel reactor, 170 g of polyether polyol A were placed and heated to 130°C. The reactor was inertized by three evacuations to 100 mbar (absolute) and repeated purging with nitrogen, and then stripped for 30 min at 100 mbar and 130°C with nitrogen purging. Subsequently, the reactor was cooled to 60°C and a pressure of 1 bar (absolute) was established using nitrogen. At 60°C, a mixture of 10 g of polyether polyol A and 0.05 g of trifluoromethanesulfonic acid (0.08 mol% based on the total amount of lactone used) was added, followed by 31.7 g of beta-propiolactone (corresponding to the total amount of beta-propiolactone; molar ratio of lactone to hydroxy end groups of polyether polyol A: 4 / 1). The reaction mixture was stirred for 2 hours at 60°C and then cooled to room temperature. A lactone conversion of 94% was determined by IR spectroscopy.The number mean M n of the molecular weight of the product is 8133 g / mol, the polydispersity is 1.10 and the proportion of primary hydroxy end groups is 85%. Example 8:

[0110] In a 500 ml three-necked round-bottom flask, 180 g of polyether polyol A were placed, heated to 60°C, and 0.05 g of trifluoromethanesulfonic acid (0.08 mol% based on the total amount of lactone used) were added. Subsequently, 31.7 g of beta-propiolactone (corresponding to the total amount of beta-propiolactone; molar ratio of lactone to hydroxy end groups of polyether polyol A: 4 / 1) were added continuously over a period of 45 min. After complete addition of the lactone, the reaction mixture was stirred for 75 min at 60°C and then cooled to room temperature. A lactone conversion of 97% was determined by IR spectroscopy. The number-average molecular weight Mn of the product was 8113 g / mol, the polydispersity was 1.11, and the proportion of primary hydroxy end groups was 80%. Example 9 (comparative example):

[0111] In a 2-liter stainless steel reactor, 200 g of polyether polyol A were placed and heated to 130°C. The reactor was inertized by three evacuations to 100 mbar (absolute) and repeated purging with nitrogen, and then stripped for 30 min at 100 mbar and 130°C with continuous nitrogen purging. Subsequently, the reactor was cooled to 100°C and a pressure of 1 bar (absolute) was established using nitrogen. 5 g of beta-propiolactone were added, and the reaction mixture was stirred for 2 hours at 100°C. Subsequently, beta-propiolactone was added in 5 g portions (or 5.3 g for the last portion) at 15-minute intervals (total amount of beta-propiolactone: 35.3 g; molar ratio of lactone to hydroxy end groups of polyether polyol A: 4 / 1). After complete addition of the lactone, the reaction mixture was stirred for 30 min at 100°C and then cooled to room temperature. A lactone conversion of 4% was determined by IR spectroscopy.The number mean M n of the molecular weight of the product is 6721 g / mol, the polydispersity is 1.03 and the proportion of primary hydroxy end groups is 31%. Example 10 (comparative example):

[0112] In a 2-liter stainless steel reactor, 200 g of polyether polyol A and 0.18 g of DMC catalyst (prepared according to Example 6 in WO 01 / 80994 A1) were placed and heated to 130°C. The reactor was inertized by three evacuations to 100 mbar (absolute) and repeated purging with nitrogen, and then stripped for 30 min at 100 mbar and 130°C with nitrogen purging. Subsequently, the reactor was cooled to 100°C and a pressure of 1 bar (absolute) was established using nitrogen. 5 g of beta-propiolactone were added, and the reaction mixture was stirred for 2 hours at 100°C. Subsequently, beta-propiolactone was added in 5 g portions (or 5.3 g for the last portion) at 15-minute intervals (total amount of beta-propiolactone: 35.3 g; molar ratio of lactone to hydroxy end groups of polyether polyol A: 4 / 1). After complete addition of the lactone, the reaction mixture was stirred for 30 min at 100°C and then cooled to room temperature.A lactone conversion of 5% was determined by IR spectroscopy. The number mean Mn of the molecular weight of the product is 6666 g / mol, the polydispersity is 1.02, and the proportion of primary hydroxyl end groups is 28%. Example 11 (comparative example):

[0113] In a 2-liter stainless steel reactor, 170 g of polyether polyol A were placed and heated to 130°C. The reactor was inertized by three evacuations to 100 mbar (absolute) and repeated purging with nitrogen, and then stripped for 30 min at 100 mbar and 130°C with nitrogen purging. Subsequently, the reactor was cooled to 60°C and a pressure of 1 bar (absolute) was established using nitrogen. At 60°C, a mixture of 10 g of polyether polyol A and 0.14 g of tin(II) 2-ethylhexanoate (0.08 mol% based on the total amount of lactone used) was added, followed by 5 g of beta-propiolactone. The reaction mixture was stirred for 2 hours at 60°C. Subsequently, beta-propiolactone was added in portions of 5 g (or last portion: 6.7 g) at 15-minute intervals (total amount of beta-propiolactone: 31.7 g; molar ratio of lactone / hydroxy end groups of polyether polyol A: 4 / 1).After complete addition of lactone, the reaction mixture was stirred for 30 min at 60°C and then cooled to room temperature. A lactone conversion of 2% was determined by IR spectroscopy. The number-average molecular weight Mn of the product is 6675 g / mol, the polydispersity is 1.07, and the proportion of primary hydroxyl end groups is 12%. Example 12 (comparative example):

[0114] In a 2-liter stainless steel reactor, 190 g of polyether polyol A were placed and heated to 130°C. The reactor was inertized by three evacuations to 100 mbar (absolute) and repeated purging with nitrogen, and then stripped for 30 min at 100 mbar and 130°C with nitrogen purging. Subsequently, the reactor was cooled to 60°C and a pressure of 1 bar (absolute) was established using nitrogen. At 60°C, a mixture of 10 g of polyether polyol A and 0.16 g of tin(II) 2-ethylhexanoate (0.08 mol% based on the total amount of lactone used) was added, followed by 5 g of epsilon-caprolactone. The reaction mixture was stirred for 2 hours at 60°C. Subsequently, epsilon-caprolactone was added in portions of 5 g (or last portion: 5.8 g) at 15-minute intervals (total amount of epsilon-caprolactone: 55.8 g; molar ratio of lactone / hydroxy end groups of polyether polyol A: 4 / 1).After complete addition of lactone, the reaction mixture was stirred for 30 min at 60°C and then cooled to room temperature. IR spectroscopy revealed a lactone conversion of 0%. The number-average molecular weight Mn of the product is 6675 g / mol, the polydispersity is 1.06, and the proportion of primary hydroxyl end groups is 13%. Table 1: Comparison of trials 1 to 12. Attempt Addition of lactone a)< Lactone b)< Polyoxyalkylene polyol Catalyst or c)< x(Cat) [mol-%] d)< Lactone / hydroxyl end groups of the polyoxyalkylene polyol [mol / mol] T [°C] X(Lactone) [%] Primary OH end groups [%] M n [g / mol] PDI 1 sw PL Polyether polyol A TfOH 0,08 2 / 1 60 80 85 7424 1,11 2 sw PL Polyether polyol A TfOH 0,08 3,3 / 1 60 95 89 7782 1,10 3 sw PL Polyether polyol A TfOH 0,08 4 / 1 60 100 96 8071 1,11 4 sw PL Polyether polyol A TfOH 0,08 4 / 1 60 100 82 8083 1,10 5 sw PL Polyether polyol A TfOH 0,25 4 / 1 60 100 93 7696 1,05 6 sw PL Polyether polyol A TfOH 0,08 4 / 1 100 100 85 8374 1,14 7 batch PL Polyether polyol A TfOH 0,08 4 / 1 60 94 85 8133 1,10 8 conti PL Polyether polyol A TfOH 0,08 4 / 1 60 97 80 8113 1,11 9 (See below) sw PL Polyether polyol A DMC act - 4 / 1 100 4 31 6721 1,03 10 (See below) sw PL Polyether polyol A DMC active + DMC fresh - 4 / 1 100 5 28 6666 1,02 11 (See below) sw PL Polyether polyol A SN-Kat 0,08 4 / 1 60 2 12 6775 1,07 12 (See below) sw CL Polyether polyol A SN-Kat 0,08 4 / 1 60 0 13 6776 1,06 a) Lactone addition: semi-batch mode with stepwise lactone addition (sw); batch mode (batch); semi-batch mode with continuous lactone addition (conti) b) beta-propiolactone (PL), epsilon-caprolactone (CL) c) trifluoromethanesulfonic acid (TfOH); DMC catalyst (DMC act) contained in the production of polyether polyol A from the preparation of polyether polyol A; DMC catalyst (DMC fresh) added to polyether polyol A; tin(II) 2-ethylhexanoate (Sn-Kat) d) based on the amount of lactone used

Claims

1. Process for preparing a polyoxyalkylene polyester polyol by reacting a polyoxyalkylene polyol with a lactone in the presence of a Bronsted-acidic catalyst, wherein the catalyst has a pKa value of 1 or less; wherein the number-average molar mass of the polyoxyalkylene polyol is ≥ 1000 g / mol, preferably ≥ 1500 g / mol, particularly preferably ≥ 2000 g / mol; wherein in the lactone a CH2 group is bonded to the ring oxygen; and wherein the polyoxyalkylene polyol has a content of secondary OH end groups of at least 75%, based on the sum of primary and secondary OH end groups, wherein the secondary OH end groups have been determined by 1H NMR spectroscopy as disclosed in the experimental section.

2. Process according to Claim 1, wherein the lactone is one or more compounds selected from the group consisting of beta-propiolactone, gamma-butyrolactone, delta-valerolactone and epsilon-caprolactone, preferably beta-propiolactone.

3. Process according to either of Claims 1 and 2, wherein the molar ratio of lactone to the hydroxyl end groups of the polyoxyalkylene polyol is 1:1 to 20:1, preferably from 1.5:1 to 10:1 and particularly preferably from 2:1 to 6:1.

4. Process according to any of Claims 1 to 3, wherein the Bronsted-acidic catalyst is one or more compound(s) selected from the group consisting of trifluoromethanesulfonic acid, perchloric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, nitric acid, methanesulfonic acid, trichloroacetic acid and trifluoroacetic acid, preferably trifluoromethanesulfonic acid.

5. Process according to any of Claims 1 to 4, wherein the Bronsted-acidic catalyst is used in an amount of 0.001 mol% to 0.5 mol%, preferably of 0.003 to 0.4 mol% and particularly preferably of 0.005 to 0.3 mol%, based on the amount of lactone.

6. Process according to any of Claims 1 to 5, wherein the polyoxyalkylene polyol is a polyether polyol and / or polyether carbonate polyol.

7. Process according to any of Claims 1 to 6, wherein the polyoxyalkylene polyol is a polyether polyol and the polyether polyol has been prepared by reaction of an H-functional starter substance with alkylene oxides in the presence of a double metal cyanide catalyst.

8. Process according to any of Claims 1 to 6, wherein the polyoxyalkylene polyol is a polyether carbonate polyol and the polyether carbonate polyol has been prepared by reaction of an H-functional starter substance with alkylene oxides and carbon dioxide in the presence of a double metal cyanide catalyst.

9. Process according to Claim 7 or 8, wherein the alkylene oxide is ethylene oxide and / or propylene oxide.

10. Process according to Claim 9, wherein the weight fraction of propylene oxide is 80% by weight to 100% by weight, based on the sum of the masses of propylene oxide and ethylene oxide metered in.

11. Process according to any of Claims 1 to 9, wherein the process is performed without addition of a solvent.

12. Polyoxyalkylene polyester polyol, preferably polyether polyester polyol and / or polyether carbonate polyester polyol, obtainable according to at least one of Claims 1 to 11, wherein the polyoxyalkylene polyester polyol has a content of primary OH end groups of at least 80%, based on the sum of primary and secondary OH end groups, wherein the primary OH end groups have been determined by 1H or 13C NMR spectroscopy as disclosed in the experimental section.

13. Polyoxyalkylene polyester polyol, preferably polyether polyester polyol and / or polyether carbonate polyester polyol, according to Claim 12, wherein the polyoxyalkylene polyester polyol has a polydispersity index of ≤ 1.20, preferably ≤ 1.15, wherein the polydispersity index has been determined by gel permeation chromatography as disclosed in the experimental section.

14. Process for preparing a polyurethane by reaction of the polyoxyalkylene polyester polyol, preferably the polyether polyester polyol and / or the polyether carbonate polyester polyol, according to Claim 12 or 13 with a polyisocyanate.