Compound containing oximic hydroxyl groups, and process of preparation of same

Abstract

The present invention relates to a compound containing oximic hydroxyl groups and to a process of preparing same. The invention further relates to a process for preparing a polyurethane, comprising the reaction of the compound containing oximic hydroxyl groups, to the polyurethanes resulting therefrom and to a thermal treatment of this polyurethane.

Description

[0001] Compound containing oximic hydroxyl groups and process for its preparation

[0002] The present invention relates to a compound containing oximic hydroxyl groups and a process for its preparation. Furthermore, the invention extends to a process for producing a polyurethane comprising reacting the compound containing oximic hydroxyl groups, the resulting polyurethanes, and a thermal treatment of this polyurethane.

[0003] The prior art describes various methods for producing polyurethanes, such as polyurethane foams or compact polyurethanes, with material and energy recovery, such as the recycling of polyurethanes, becoming increasingly relevant. A challenge here is the thermal and chemical stability of the polyurethane bond (PU bond), which is typically formed by the addition reaction of a polyisocyanate component containing two or more isocyanate groups with a polyol component containing two or more aliphatic hydroxyl groups (OH groups).Currently, pyrolysis or chemolysis processes are described for the material reuse of PU. Bond cleavage during the pyrolysis reaction, usually at elevated temperatures well above 200 °C, is unspecific due to the generally radical reaction mechanism, resulting in fragments that cannot be reused, or at least not directly, in PU production. This undefined fragmentation can be avoided by chemolysis processes, for example by using water (hydrolysis) and / or alcohols such as glycols (glycolysis), which typically result in a carbamate and polyol phase. A disadvantage of chemolysis processes is the use of excess water or alcohols. These reactants or possibly additional solvents must be separated, for example, by downstream energy-intensive distillation steps, which involve increased process complexity and time expenditure.Before PU can be recycled, the polyol phase formed must be separated from the carbamate phase and purified, or the carbamate formed must be cleaved to the amine in additional, (safety-)technically complex process steps and converted into the isocyanate component by phosgenation.

[0004] The object of the present application was to provide hydroxyl-containing compounds as a polyol component for the production of a polyurethane by reaction with a polyisocyanate component to form urethane bonds. This would enable improved reuse of the polyurethane compared to the prior art, for example, by cleavage and relinking of at least some of the urethane bonds as reversibly as possible, thus enabling the reuse of the polyurethane without completely disrupting the overall polyurethane structure, as occurs in prior art chemolysis processes by reaction with alcohols and / or water. Thus, complex recycling processes involving the use of various additional reactants or solvents and their separation, for example, by using energy-intensive, thermal, and / or extractive separation methods, can be avoided.It is also the aim of the invention that the polyurethanes produced using the novel hydroxyl-containing compounds as a polyol component, such as polyurethane foams or compact polyurethanes, have at least comparable property profiles, such as mechanical properties, to polyurethanes produced using known polyol components. It is particularly advantageous and also an object of the invention to produce the hydroxyl-containing compound as a polyol component by a simple reaction from a polyol component generally known from polyurethane chemistry, wherein the hydroxyl-containing compound advantageously also catalyzes the polyurethane formation reaction, but at least does not contain any elements that potentially impair the polyurethane formation reaction, such as sulfur.

[0005] Surprisingly, it has now been found that a hydroxyl group-containing compound (A), wherein at least some of the hydroxyl groups are oximic hydroxyl groups, wherein the hydroxyl group-containing compound (A) is composed of the elements carbon, hydrogen, oxygen and nitrogen, wherein the hydroxyl group-containing compound (A) has an OH number (determined by means of DIN 4629-2 (December 2016)) of 10 mg KOH / g to 600 mg KOH / g, preferably of 12 mg KOH / g to 500 mg KOH / g, and wherein the hydroxyl group-containing compound (A) contains oxypropylene units, achieves the above-mentioned object.

[0006] According to the invention, oximes are understood to be derivatives of aldehydes or ketones which contain the group C=N-OH as a functional group, wherein the corresponding hydroxyl group is defined as an oximic hydroxyl group.

[0007] The invention is explained in detail below, whereby the embodiments according to the invention can be combined with one another as desired, unless the technical context indicates otherwise.

[0008] In one embodiment of the invention, the hydroxyl-containing compound (A) contains ether units, preferably oxyethylene and oxypropylene units. The oxyethylene and / or oxypropylene units can be formed by ring opening of ethylene oxide and / or propylene oxide on an H-functional starter compound.

[0009] In a preferred embodiment of the invention, the hydroxyl group-containing compound (A) contains at least 3 directly consecutive oxypropylene units.

[0010] In a further preferred embodiment of the invention, the hydroxyl group-containing compound (A) contains at most 200 directly consecutive oxypropylene units.

[0011] In one embodiment of the invention, the OH number of the hydroxyl group-containing compound (A) is from 12 mg KOH / g to 500 mg KOH / g, particularly preferably from 15 mg KOH / g to 500 mg KOH / g. In one embodiment of the invention, the calculated proportion of the oximic hydroxyl groups is from 20 mol% to 100 mol%, preferably from 25 mol% to 100 mol%, particularly preferably from 30 mol% to 100 mol%, and very particularly preferably from 35 mol% to 100 mol%, based on the sum of all free hydroxyl groups of the hydroxyl group-containing compound (A). In addition to calculating the proportion of the oximic hydroxyl groups, their proportion can also be determined experimentally by an OH number determination in conjunction with 'H- and 13 C NMR spectroscopy, as demonstrated in Example 1 of the experimental section. The experimentally determined values ​​show very good agreement with the calculated proportions.

[0012] In one embodiment of the invention, the hydroxyl group-containing compound (A) has a calculated hydroxyl group functionality of 1 to 8, preferably of 2 to 6 and particularly preferably of 2 to 4.

[0013] The invention also relates to a process for preparing the hydroxyl group-containing compound (A) according to the invention, comprising the steps: i) reacting a component (B) containing one or more aliphatic hydroxyl group(s) with a component (C) containing (C1) one or more hydroxyl group-reactive functional group(s) and (C-2) one or more carbonyl group(s), optionally in the presence of a catalyst (D) to form an intermediate (E), and ii) reacting the intermediate (E) with hydroxylamine and / or salts of hydroxylamine, preferably hydroxylamine.

[0014] According to the invention, aliphatic hydroxyl groups are understood, in accordance with common technical knowledge, to be hydroxyl groups that are directly bonded to alkylene groups, such as CtU groups. Thus, aryl hydroxyl groups are excluded.

[0015] In one embodiment of the invention, the aliphatic hydroxyl groups of component (B) are primary and / or secondary hydroxyl groups.

[0016] In one embodiment of the invention, component (B) is obtainable by reacting an H-functional starter compound (F) with an alkylene oxide (G) in the presence of a catalyst (H). In a preferred embodiment of the invention, component (B) is obtained by reacting an H-functional starter compound (F) with an alkylene oxide (G) in the presence of a catalyst (H).

[0017] In one embodiment of the invention, component (C) containing (C1) one or more hydroxyl group-reactive functional group(s) and (C-2) one or more carbonyl group(s), a carboxylic acid group and / or a carboxylic acid chloride group, a carboxylic acid ester group, preferably a carboxylic acid group.

[0018] In one embodiment of the invention, component (C) containing (C1) one or more hydroxyl group-reactive functional group(s) and (C2) one or more carbonyl group(s) is an aliphatic component (C) which is composed only of aliphatic units, i.e. no aromatic units such as phenyl groups. In a preferred embodiment of the invention, component (C) containing (C1) one or more hydroxyl group-reactive functional group(s) and (C2) one or more carbonyl group(s) is one or more compounds and is selected from the group consisting of levulinic acid, acetoacetic acid, pyruvic acid, α-methyllevulinic acid, 3-methyl-4-oxopentanoic acid, 4-oxo-2-propylpentanoic acid, 2-acetyl-4-methylpentanoic acid, preferably levulinic acid, acetoacetic acid and pyruvic acid.

[0019] According to the invention, catalysts (D) can be added to the reaction of component (B) containing one or more aliphatic hydroxyl groups with a component (C) containing one or more hydroxyl-reactive functional groups and one or more carbonyl groups. In the case of carboxylic acid groups as hydroxyl-reactive functional groups of component (C), for example, a corresponding esterification with component (B) containing one or more aliphatic hydroxyl groups would take place.

[0020] Esterification catalysts can be used for this purpose, including, for example, tin(II) salts, such as tin dichloride, tin dichloride dihydrate, tin(II) 2-ethylhexanoate, dibutyltin dilaurate, titanium alkoxylates, such as titanium tetrabutoxide, tetraisopropyl titanate, bismuth(III) neodecanoate, zinc(II) acetate, manganese(II) acetate, or protic acids, such as p-toluenesulfonic acid. Furthermore, the esterifications can also be catalyzed by enzymes, such as esterases and / or lipases.

[0021] In one embodiment of the invention, the catalyst (D) is one or more compounds and is selected from the group consisting of tin dichloride, tin dichloride dihydrate, tin(II) 2-ethylhexanoate, dibutyltin dilaurate, titanium tetrabutoxide, tetraisopropyl titanate, bismuth(III) neodecanoate, zinc(II) acetate, manganese(II) acetate and p-toluenesulfonic acid, preferably p-toluenesulfonic acid.

[0022] According to the invention, the intermediate (E) in step i) is formed by reacting the component (B) containing one or more aliphatic hydroxyl group(s) with the component (C) containing (C-1) one or more hydroxyl group-reactive functional group(s) and (C-2) one or more carbonyl group(s), optionally in the presence of the catalyst (D).

[0023] Suitable H-functional starter compounds (F), also called starters, are compounds containing H atoms active for alkoxylation, so-called “Zerewitinoff-active” hydrogen atoms. A hydrogen bonded to N, O, or S is referred to as Zerewitinoff-active hydrogen if, according to a process discovered by Zerewitinoff, it yields methane by reaction with methylmagnesium iodide. Typical examples of compounds containing Zerewitinoff-active hydrogen are compounds containing carboxyl, hydroxyl, or amino groups as functional groups. The H-functional starter compound (F) in the process according to the invention preferably contains no sulfur-containing functional groups, in particular no thiol groups. Groups containing active H atoms that are particularly suitable for alkoxylation are -OH and -NH2, very particularly preferred is -OH.

[0024] As H-functional starter compound (F), for example, one or more compounds can be selected from the group comprising mono- or polyhydric alcohols, polyhydric amines, amino alcohols, hydroxy esters, polyether polyols, polyester polyols, polyester ether polyols, polyether carbonate polyols, polycarbonate polyols, polycarbonates, polyethyleneimines, polyetheramines (e.g. so-called Jeffamine® from Huntsman, such as D-230, D-400, D-2000, T-403, T-3000, T-5000 or corresponding products from BASF, such as Polyetheramine D230, D400, D200, T403, T5000), polytetrahydrofurans (e.g. PolyTHF® from BASF, such asPolyTHF® 250, 650S, 1000, 1000S, 1400, 1800, 2000), polytetrahydrofuranamines (BASF product Polytetrahydrofuranamine 1700), polyacrylate polyols, castor oil, the mono- or diglyceride of ricinoleic acid, monoglycerides of fatty acids, chemically modified mono-, di- and / or triglycerides of fatty acids, and C1-C24 alkyl fatty acid esters which contain on average at least 2 OH groups per molecule. For example, the C1-C23 alkyl fatty acid esters, which contain on average at least 2 OH groups per molecule, are commercial products such as Lupranol Balance® (BASF AG), Mer ginol® types (Hobum Oleochemicals GmbH), Sovermol® types (Cognis Deutschland GmbH & Co. KG) and Soyol®TM types (USSC Co.).

[0025] In a preferred embodiment of the process according to the invention, the H-functional starter compound (F) is a polyol, preferably a polyfunctional alcohol, a polyfunctional amine, a polyether polyol or a polyether ester polyol, particularly preferably a polyether polyol and / or a polyfunctional alcohol.

[0026] Also suitable as H-functional starter compounds (F) are, for example, dihydric alcohols such as ethylene glycol, diethylene glycol, 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 and triethanolamine, tetrahydric alcohols such as pentaerythritol, polyalcohols such as sorbitol, hexitol, sucrose, starch, starch hydrolysates (maltodextrin), cyclodextrins, cellulose, cellulose hydrolysates,hydroxy-functionalized fats and oils. Water is also suitable as a divalent H-functional starter compound (F) for carrying out the process according to the invention.

[0027] Amines such as ammonia, ethanolamine, diethanolamine, isopropanolamine, diisopropanolamine, ethylenediamine, pentamethylenediamine, hexamethylenediamine, aniline, the isomers of toluidine, the isomers of diaminotoluene, the isomers of diaminodiphenylmethane and higher-nuclear products obtained in the condensation of aniline with formaldehyde to diaminodiphenylmethane are also suitable as H-functional starter compounds (F).

[0028] The H-functional starter compounds (F) can also be selected from the substance class of polyether polyols, in particular from those with a number-average molar mass (Mn) in the range from 100 to 4000 g / mol. Preference is given to polyether polyols composed of repeating ethylene oxide and propylene oxide units, preferably with a proportion of 35 to 100% propylene oxide units, particularly preferably with a proportion of 50 to 100% propylene oxide units. These can be random copolymers, gradient copolymers, alternating or block copolymers of ethylene oxide and propylene oxide. Suitable polyether polyols, composed of repeating propylene oxide and / or ethylene oxide units are, for example, the Desmophen®, Acclaim®, Arcol®, Baycoll®, Bayfill®, Bayflex®, Baygal®, PET® and polyether polyols from Covestro AG (such asDesmophen® 3600Z, Desmophen® 1900U, Acclaim® Polyol 2200, Acclaim® Polyol 40001, Arcol® Polyol 1004, Arcol® Polyol 1010, Arcol® Polyol 1030, Arcol® Polyol 1070, Baycoll® BD 1110, Bayfill® VPPU 0789, Baygal® K55, PET® 1004, Polyether® S180). Other suitable homopolyethylene oxides include the Pluriol® E grades from BASF SE. Suitable homopolypropylene oxides include the Pluriol® P grades from BASF SE. Suitable mixed copolymers of ethylene oxide and propylene oxide include the Pluronic® PE or Pluriol® RPE grades from BASF SE.

[0029] The H-functional starter compounds (F) generally have an OH functionality (ie a number of H atoms per molecule active for polymerization) of 1 to 8, preferably of 2 to 6 and particularly preferably of 2 to 4. The H-functional starter compounds (F) are used either individually or as a mixture of at least two H-functional starter compounds (F).

[0030] In a preferred embodiment of the process according to the invention, the H-functional starter compounds (F) have hydroxyl numbers of 150 mg KOH / g to 6230 mg KOH / g, preferably of 200 mg KOH / g to 1850 mg KOH / g, wherein the hydroxyl number was determined by means of the method disclosed in the experimental section.

[0031] In one embodiment of the invention, the H-functional starter compound (F) is an amine and / or an alcohol, preferably an alcohol.

[0032] In one embodiment of the invention, the H-functional starter compound (F) is an alcohol, and the alcohol is one or more compounds selected from the group consisting of ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2-methylpropane-1,3-diol, neopentyl glycol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, glycerol, trimethylolpropane, a difunctional polyether polyol, and a trifunctional polyether polyol, preferably a difunctional polyether polyol and a trifunctional polyether polyol. The polyether polyol can be used individually or as a mixture.

[0033] The at least one alkylene oxide (G) used in the process according to the invention has 2 to 24 carbon atoms. The alkylene oxides (G) having 2 to 24 carbon atoms are, for example, one or more compounds selected from the group consisting of ethylene oxide, propylene oxide, 1-butene oxide, 2,3-butene oxide, 2-methyl-1,2-propene oxide (isobutene oxide), 1-pentene oxide, 2,3-pentene oxide, 2-methyl-1,2-butene oxide, 3-methyl-1,2-butene oxide, 1-hexene oxide, 2,3-hexene oxide, 3,4-hexene oxide, 2-methyl-1,2-pentene oxide, 4-methyl-1,2-pentene oxide, 2-ethyl-1,2-butene oxide, 1-heptene oxide, 1-octene oxide, 1-nonene oxide, 1-decene oxide, 1-undecene oxide, 1-dodecene oxide, 4-Methyl-l,2-pentene oxide, butadiene monoxide, isoprene monoxide, cyclopentene oxide, cyclohexene oxide, cycloheptene oxide, cyclooctene oxide, styrene oxide, methylstyrene oxide, pinene oxide, mono- or polyepoxidized fats as mono-, di- and triglycerides, epoxidized fatty acids, Ci-Cz-r-esters of epoxidized fatty acids, epichlorohydrin, glycidol,and derivatives of glycidol such as methyl glycidyl ether, ethyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, glycidyl methacrylate and epoxy-functional alkyloxysilanes such as 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropyltripropoxysilane, 3-glycidyloxypropylmethyldimethoxysilane, 3-glycidyloxypropylethyldiethoxysilane, 3-glycidyloxypropyltriisopropoxysilane.

[0034] In the process according to the invention, propylene oxide, ethylene oxide, or a mixture of ethylene oxide and propylene oxide are preferably used as the alkylene oxide (G). If mixtures of ethylene oxide and propylene oxide are used, they preferably contain up to 75% by mass of ethylene oxide, more preferably up to 50% by mass of ethylene oxide, and most preferably up to 30% by mass of ethylene oxide, based on the total mass of the mixture of ethylene oxide and propylene oxide. In particular, exclusively propylene oxide is used as the alkylene oxide (G), and mixtures of ethylene oxide and propylene oxide with up to 30% by mass of ethylene oxide, based on the total mass of the mixture of ethylene oxide and propylene oxide, are used as the alkylene oxide (G). The alkylene oxides (G) can be fed to the reactor as individual components or as a mixture.It is also possible, but less preferred, to feed several alkylene oxides (G) into the reactor successively, thus allowing the formation of polyoxyalkylene chains with a block structure. When metering several alkylene oxides (G), it is also possible to change the composition of the alkylene oxide stream fed in continuously or instantaneously.

[0035] In one embodiment of the invention, the catalyst (H) is a double metal cyanide (DMC) catalyst, an alkali metal hydroxide, an alkaline earth metal hydroxide and / or an amine, a Lewis acid or a Brønsted acid, preferably a double metal cyanide (DMC) catalyst, an alkali metal hydroxide, an alkaline earth metal hydroxide or an amine.

[0036] Double metal cyanide (DMC) catalysts suitable as catalyst (H) are in principle known from the prior art (see, for example, US-A 3,404,109, US-A 3,829,505, US-A 3,941,849, and US-A 5,158,922). DMC catalysts, which are described, for example, 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 in the polymerization of alkylene oxides and enable the preparation of polyoxyalkylene polyols under optimal conditions at very low catalyst concentrations (100 ppm or less), so that separation of the catalyst from the finished product is generally no longer necessary. A typical example are the highly active DMC catalysts described in EP-A 700949, which contain a double metal cyanide compound (e.g. zinc hexacyanocobaltate(III)) and an organic complex ligand (e.g. tert.-butanol) or a polyoxyalkylene compound with a number-average molecular weight of > 500 g / mol. It is also possible to use the alkaline DMC catalysts disclosed in EP Application No. 10163170.3.

[0037] Cyanide-free metal salts suitable for preparing the double metal cyanide compound preferably have the general formula (I),

[0038] M(X) n (I) where

[0039] 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+ ,

[0040] X is 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, cyanate, thiocyanate, isocyanate, isothiocyanate or nitrate, or suitable cyanide-free metal salts have the general formula (II),

[0041] M r (X)3(II) where

[0042] M is selected from the metal cations Fe 3+ , Al 3+ and Cr 3+ ,

[0043] X is 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; r is 2 if X = sulfate, carbonate or oxalate and r is 1 if X = halide, hydroxide, cyanate, thiocyanate, isocyanate, isothiocyanate, carboxylate or nitrate, or suitable cyanide-free metal salts have the general formula (III),

[0044] M(X) S (III) where

[0045] M is selected from the metal cations Mo 4+ , V 4+ and W 4+

[0046] X is 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, cyanate, thiocyanate, isocyanate, isothiocyanate, carboxylate or nitrate, or suitable cyanide-free metal salts have the general formula (IV),

[0047] M(X) t (IV) where

[0048] M is selected from the metal cations Mo 6+ and W 6+

[0049] X is 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; t is 3 if X = sulfate, carbonate or oxalate and t is 6 if X = halide, hydroxide, cyanate, thiocyanate, isocyanate, isothiocyanate, carboxylate or nitrate,

[0050] Examples of suitable cyanide-free metal salts are zinc chloride, zinc bromide, zinc iodide, zinc acetate, zinc acetylacetonate, zinc benzoate, zinc nitrate, iron(II) sulfate, iron(II) bromide, iron(II) chloride, cobalt(II) chloride, cobalt(II) thiocyanate, nickel(II) chloride, and nickel(II) nitrate. Mixtures of different metal salts can also be used.

[0051] Metal cyanide salts suitable for the preparation of the double metal cyanide compounds preferably have the general formula (V)

[0052] (Y) a M'(CN)b (A) c (V) where

[0053] M' is selected from one or more metal cations from 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 from the group consisting of Co(II), Co(III), Fe(II), Fe(III), Cr(III), Ir(III) and Ni(II),

[0054] Y is selected from one or more metal cations of the group consisting of alkali metal (ie Li + , N / a + , K + , Rb + , Cs + ) and alkaline earth metal (ie Be 2+ , Ca 2+ , Mg 2+ , Sr 2+ , Ba 2+ ),

[0055] 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, oxalate, or nitrate, and a, b, and c are integers, the values ​​for a, b, and c being chosen to ensure electroneutrality of the metal cyanide salt; a is preferably 1, 2, 3, or 4; b is preferably 4, 5, or 6; c is preferably 0.

[0056] Examples of suitable metal cyanide salts are potassium hexacyanocobaltate(III), potassium hexacyanoferrate(II), potassium hexacyanoferrate(III), calcium hexacyanocobaltate(III) and lithium hexacyanocobaltate(III).

[0057] Preferred double metal cyanide compounds contained in the DMC catalysts according to the invention are compounds of the general formula (VI)

[0058] M x [M' x ,(CN) y ] z(VI), wherein M is as defined in formula (IV) to (VII) and M' is as defined in formula (VIII), and x, x', y and z are integers and chosen so that the electron neutrality of the double metal cyanide compound is given.

[0059] Preferably x = 3, x' = 1, y = 6 and z = 2,

[0060] M = Zn(II), Fe(II), Co(II) or Ni(II) and

[0061] M' = Co(III), Fe(III), Cr(III) or Ir(III).

[0062] Examples of suitable double metal cyanide compounds 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-A 5158922 (column 8, lines 29-66). Zinc hexacyanocobaltate(III) is particularly preferred.

[0063] The organic complex ligands added during the preparation of the DMC catalysts are disclosed, for example, in US-A 5158922 (see in particular column 6, lines 9 to 65), US-A 3404109, US-A 829505, US-A 3941849, EP-A 700949, EP-A 761708, JP-A 4145123, US-A 5470813, EP-A 743093 and WO-A 97 / 40086. For example, water-soluble organic compounds containing 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 which contain 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-oxetane 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-oxetane methanol.

[0064] Optionally, in the production of the DMC catalysts, one or more complexing components from the compound classes of polyoxyalkylene compounds, 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 ether, polyvinyl ethyl ether, 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, hydroxyethyl cellulose and polyacetals, or the 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.

[0065] In the preparation of the DMC catalysts, the aqueous solutions of the metal salt (e.g., zinc chloride), used in a stoichiometric excess (at least 50 mol%) based on the metal cyanide salt (i.e., at least a molar ratio of cyanide-free metal salt to metal cyanide salt of 2.25 to 1.00), and the metal cyanide salt (e.g., potassium hexacyanocobaltate) are preferably reacted in the presence of the organic complex ligand (e.g., tert-butanol) in the first step to form a suspension containing the double metal cyanide compound (e.g., zinc hexacyanocobaltate), water, excess cyanide-free metal salt, and the organic complex ligand. The organic complex ligand can be present in the aqueous solution of the cyanide-free metal salt and / or the metal cyanide salt, or it is 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 cyanide-free metal salt and the metal cyanide salt and the organic complexing ligand with vigorous stirring. Optionally, the suspension formed in the first step is then treated with another 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., preparing the suspension) is carried out using a mixing nozzle, particularly preferably using a jet disperser as described in WO-A 01 / 39883.

[0066] In the second step, the solid (i.e. the precursor of the catalyst according to the invention) is isolated from the suspension by known techniques such as centrifugation or filtration.

[0067] In a preferred embodiment for producing the DMC catalyst, 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, water-soluble byproducts, such as potassium chloride, can be removed from the catalyst. The amount of the organic complex ligand in the aqueous wash solution is preferably between 40 and 80% by mass, based on the total solution.

[0068] Optionally, in the third step, one or more further complex-forming components are added to the aqueous washing solution, preferably in the range between 0.5 and 5 mass%, based on the total solution.

[0069] It is also advantageous to wash the isolated solid more than once. For this purpose, the first washing process can be repeated, for example. However, it is preferable to use non-aqueous solutions for subsequent washing processes, e.g., a mixture of organic complexing ligand and another complex-forming component. The isolated and optionally washed solid is then dried, optionally after pulverization, at temperatures of generally 20-100 °C and at absolute pressures of generally 0.1 mbar to atmospheric pressure (1013 mbar).

[0070] A preferred method for isolating the DMC catalysts from the suspension by filtration, filter cake washing and drying is described in WO-A 01 / 80994.

[0071] In the process according to the invention, alkali metal hydroxides, such as sodium hydroxide, potassium hydroxide, or cesium hydroxide, or alkaline earth metal hydroxides, such as magnesium hydroxide, calcium hydroxide, strontium hydroxide, or barium hydroxide, can also be used as catalysts for preparing component (B). The alkali or alkaline earth metal hydroxides can be used as solids or as highly concentrated aqueous solutions.

[0072] Sodium hydroxide and / or potassium hydroxide are very particularly preferably used as alkali metal hydroxide catalysts in the process according to the invention.

[0073] An overview of amines suitable as catalysts for the preparation of component (B) in the process according to the invention has been provided by M. lonescu et al. in "Advances in Urethanes Science and Technology", 1998, 14, pp. 151-218. For example, N,N-dimethylbenzylamine, dimethylaminopropanol, N-methyldiethanolamine, trimethylamine, triethylamine, N,N-dimethylcyclohexylamine, N-methylpyrrolidine, N,N,N',N'-tetramethylethylenediamine, diazabicyclo[2,2,2]octane, 1,4-dimethylpiperazine, N-methylmorpholine, unsubstituted imidazole, and / or alkyl-substituted imidazole derivatives can be used.

[0074] In a less preferred alternative of the invention, the hydroxyl group-containing compound (A) according to the invention is prepared comprising the steps: a) oxidation of component (B) containing one or more aliphatic hydroxyl group(s) to a compound containing one or more aliphatic carbonyl group(s) b) reaction of the product from a) with hydroxylamine and / or salts of hydroxylamine, preferably hydroxylamine.

[0075] In a further, less preferred alternative of the invention, the hydroxyl group-containing compound (A) according to the invention is prepared comprising the steps: c) reacting a compound containing one or more primary and / or secondary amino groups with an oxidizing agent d) optionally reacting the product from step c) with component (B).

[0076] In an additional, likewise less preferred alternative of the invention, the hydroxyl group-containing compound (A) according to the invention is prepared comprising the steps: e) reacting a compound containing one or more nitro groups with an alkylating agent, such as, for example, benzyl bromide, under basic conditions to form an O-alkyl nitronate, which then reacts further to form an oxime f) optionally reacting the product from e) with component (B). In an additional, likewise less preferred alternative of the invention, the hydroxyl group-containing compound (A) according to the invention is prepared comprising the steps: g) esterifying a compound containing one or more carboxyl group(s) with a hydroxycarbonyl compound h) reacting the product from g) with hydroxylamine and / or salts of hydroxylamine, preferably hydroxylamine.

[0077] In an additional, likewise less preferred alternative of the invention, the hydroxyl group-containing compound (A) according to the invention is prepared comprising the steps: j) reduction of a compound containing one or more carboxyl groups to a compound containing one or more aldehyde group(s) k) reaction of the product from j) with hydroxylamine and / or salts of hydroxylamine, preferably hydroxylamine.According to the invention, salts of hydroxylamine, preferably inorganic salts of hydroxylamine such as bis(hydroxylammonium) sulfate, tris(hydroxylammonium) phosphate, hydroxylammonium nitrate, hydroxylammonium chloride, hydroxylammonium bromide or hydroxylammonium iodide can also be used.

[0078] The invention also provides the hydroxyl-containing compound (A) obtainable by the process according to the invention. In one embodiment, the compound (A) is sulfur-free.

[0079] The invention further relates to a process for producing a polyurethane (I), preferably a polyurethane foam (I-1) or a compact polyurethane (I-2) by reacting the components

[0080] (J) containing

[0081] (Jl) the hydroxyl group-containing compound (A) according to the invention or the hydroxyl group-containing compound (A) obtainable by the process according to the invention,

[0082] (J-2) optionally a further isocyanate-reactive component

[0083] (K) where appropriate

[0084] (Cl) catalyst, and / or

[0085] (K-2) Auxiliary and additive substance

[0086] (L) where applicable

[0087] (L) Propellant, preferably water, with

[0088] (M) a polyisocyanate.

[0089] In one embodiment of the invention, the polyurethane (I) is a polyurethane foam (1-1), wherein the reaction takes place in the presence of a blowing agent (L), preferably water and / or a physical blowing agent.

[0090] In a preferred embodiment of the invention, the polyurethane foam (I-1) is a flexible polyurethane foam (I-1a), a rigid polyurethane foam (I-1b) or a viscoelastic polyurethane foam (I-1c), wherein the aforementioned foams can be produced by methods known to the person skilled in the art.

[0091] In one embodiment of the invention, the flexible polyurethane foam (I-1a) is produced at an index of 90 to 120, wherein the production takes place in the presence of the blowing agent (L) which contains 0.8 to 4.5 parts by weight of water, based on the sum of the parts by weight of components (I-1) and (I-2), wherein the sum of the parts by weight of components (I-1) and (I-2) is 100. The index is defined as the ratio of isocyanate groups to hydroxyl groups multiplied by a factor of 100, with one water molecule contributing 2 hydroxyl groups in this calculation. Flexible polyurethane foams and their production processes are generally known to the person skilled in the art, as described, for example, in G. Oertel (ed.): "Polyurethane Handbook", 2nd Edition, Carl-Hanser-Verlag, Munich, Vienna 1993, pp. 177-246.

[0092] In one embodiment of the invention, the rigid polyurethane foam (I-1b) is produced at a density of 90 to 600, the production being carried out in the presence of the blowing agent (L) which contains 5 to 25 parts by weight of a blowing agent, preferably a physical blowing agent such as pentane, based on the sum of the parts by weight of components (Il) and (I-2), the sum of the parts by weight of components (Il) and (I-2) being 100. Rigid polyurethane foams and their production processes are generally known to the person skilled in the art, as described, for example, in G. Oertel (ed.): “Polyurethane Handbook”, 2nd Edition, Carl-Hanser-Verlag, Munich, Vienna 1993, pp. 247-328.

[0093] In an alternative embodiment of the invention, the polyurethane (I) is a compact polyurethane (I-2), wherein the preparation of the compact polyurethane takes place in the absence of the blowing agent (L) and / or moisture. Compact polyurethanes and their preparation processes are generally known to the person skilled in the art, as described, for example, in G. Oertel (ed.): "Polyurethane Handbook," 2nd Edition, Carl-Hanser-Verlag, Munich, Vienna 1993, pp. 387-478.

[0094] In addition to the hydroxyl group-containing compound (A) according to the invention as a component, a further polyoxyalkylene polyol such as a polyester polyol, a polycarbonate polyol, a polyether carbonate polyol, a polyester carbonate polyol, a polyether ester carbonate polyol and / or a low molecular weight chain extender and / or crosslinking agent having OH numbers or NH numbers of 6 to 1870 mg KOH / g can optionally be added as a further isocyanate-reactive component (J-2).

[0095] Further polyoxyalkylene 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 Brpnsted or Lewis acids such as trifluoromethanesulfonic acid, perchloric acid, antimony pentachloride, boron trifluoride etherate or tris(pentafluorophenyl)borane. Suitable catalysts are, of course, also those of the double metal cyanide complex type, 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, for example, tetrahydrofuran as a Lewis acid-polymerizable cyclic ether and water as a starter molecule. The other polyoxyalkylene polyols, preferably polyoxypropylene-polyoxyethylene polyols, preferably have number-average molecular weights of 200 to 8000 Da. Other suitable polyoxyalkylene polyols include polymer-modified polyoxyalkylene polyols, preferably graft polyoxyalkylene polyols, particularly those based on styrene and / or acrylonitrile, which are obtained by in-situ polymerization of acrylonitrile and / or styrene or, preferably, mixtures of styrene and acrylonitrile, e.g., in a weight ratio of 90:10 to 10:90. preferably 70:30 to 30:70, advantageously prepared in the aforementioned further polyoxyalkylene polyols, and polyoxyalkylene polyol dispersions which contain as disperse phase, usually in an amount of 1 to 50% by weight, preferably 2 to 25% by weight, inorganic fillers, polyureas, polyhydrazides, tert.- contain polyurethanes and / or melamine containing amino groups.

[0096] 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 mono- and / or diesters of alcohols having 1 to 4 carbon atoms or dicarboxylic acid anhydrides, can also be used. Preferably used are dicarboxylic acid mixtures of succinic, glutaric and adipic acid in proportions of, for example, 20 to 35 / 40 to 60 / 20 to 36 wt.Parts and especially adipic acid. Examples of dihydric and polyhydric alcohols are ethanediol, diethylene glycol, 1,2- and

[0097] 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, glycerin, trimethylolpropane, and pentaerythritol. 1,2-ethanediol, diethylene glycol,

[0098] 1,4-butanediol, 1,6-hexanediol, glycerin, trimethylolpropane, or mixtures of at least two of the polyhydric alcohols mentioned, in particular mixtures of ethanediol, 1,4-butanediol, and 1,6-hexanediol, glycerin, and / or trimethylolpropane. Polyester polyols derived from lactones, e.g., caprolactone, or hydroxycarboxylic acids, e.g., hydroxycaproic acid and hydroxyacetic acid, can also be used.

[0099] 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 values. The acid number is advantageously less than 10 mg KOH / g, preferably less than 2.5 mg KOH / g.

[0100] According to a preferred production 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. Examples of suitable esterification catalysts are 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 entraining agents, such as benzene, toluene, xylene or chlorobenzene, for the azeotropic distillation of the condensation water.

[0101] 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.

[0102] Suitable polycarbonate polyols are those of a type known per se, which 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, oligo-tetramethylene glycol and / or oligo-hexamethylene glycol with diaryl carbonates and / or dialkyl carbonates, e.g., diphenyl carbonate, dimethyl carbonate, and 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 double metal cyanide (DMC) compounds.

[0103] Low-molecular-weight, preferably tri- or tetrafunctional crosslinking agents or difunctional chain extenders can be used as additional isocyanate-reactive components (J-2). Suitable crosslinking agents, e.g., tri- or tetrahydric alcohols and oligomeric polyoxyalkylene polyols with a functionality of 3 to 4, typically have molecular weights of 90 to 300 Da. Suitable crosslinking agents include, for example, glycerol, trimethylolpropane, or pentaerythritol. Preferred 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 especially 1,4-butanediol and dialkylene glycols having 4 to 8 carbon atoms, e.g. diethylene glycol and dipropylene glycol. Also suitable are branched-chain and / or unsaturated alkanediols having usually no more than 12 carbon atoms, such as1,2-Propanediol, 2-methyl-l,3-propanediol, 3-methyl-l,5-pentanediol, 2,2-dimethyl-l,3-propanediol, 2-butyl-2-ethyl-l,3-propanediol, 2-butene-l,4-diol and 2-butyne-l,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-l,4-butylene glycol ester and hydroxyalkylene ethers of hydroquinone or resorcinol, e.g. l,4-di-(ß-hydroxyethyl)-hydroquinone or l,3-(ß-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 with 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'-diamino-dicyclohexylmethane, N-alkyl-, N,N' dialkyl-substituted and aromatic diamines, which may also be substituted on the aromatic radical by alkyl groups, with 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 see. butylbenzidine, methylene-bis(4-amino-3-benzoic acid methyl ester), 2,4-chloro-4,4'-diamino-diphenylmethane, 2,4- and 2,6-toluylenediamine can be used.

[0104] Mixtures of different chain extenders and crosslinking agents as well as mixtures of chain extenders and crosslinking agents can also be used.

[0105] Amine catalysts familiar to the person skilled in the art can be used as catalyst (K1), e.g. 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), l,4-diazabicyclo-(2,2,2)-octane, N-methyl-N'-dimethylaminoethylpiperazine, bis-(dimethylaminoalkyl)-piperazines (DE-A 26 36 787), N,N-dimethylbenzylamine, N,N-

[0106] Dimethylcyclohexylamine, N,N-diethylbenzylamine, bis-(N,N-diethylaminoethyl)adipate, N,N,N',N'-tetramethyl-1,3-butanediamine, N,N-dimethyl-ß-phenylethylamine, 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 (Kl) are known Mannich bases derived 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 with hydrogen atoms active toward isocyanate groups can also be used as catalysts (Kl), e.g.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 Pat. No. 3,620,984, e.g., 2,2,4-trimethyl-2-silamorpholine and 1,3-diethylaminomethyltetramethyldisiloxane, can also be used as catalysts (K1). The reaction between isocyanate groups and Zerewitinoff-active hydrogen atoms is also strongly accelerated by lactams and azalactams, whereby initially an association is formed between the lactam and the compound with acidic hydrogen.

[0107] If amines are used as catalysts (K1) to catalyze the polyurethane reaction, it should of course be noted that polyoxyalkylene polyols produced under amine catalysis may already contain catalytically active amines. However, by conducting appropriate test series, it is easy for the skilled person to determine the amounts of amine catalysts that may still need to be added.

[0108] Furthermore, conventional organic metal compounds can be used as catalysts (K1) 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, less preferably, 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.

[0109] Catalysts (K1) that specifically catalyze the trimerization of isocyanate 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 K values ​​of 180 to 600. Catalysts (K1) that contribute to the formation of isocyanurate structures are metal salts such as potassium or sodium acetate, sodium octoate, and amino compounds such as 1,3,5-tris(3-dimethylaminopropyl)hexahydrotriazine.

[0110] The catalysts (Kl) or catalyst combinations of different catalysts (Kl) are generally used in amounts of between about 0.001 and 10 wt.%, in particular 0.01 to 4 wt.%, based on the total amount of components (Jl) and (J-2).

[0111] During the production of the polyurethane (I), auxiliaries and additives (K-2) may optionally be used. 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. Suitable 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 metal 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 may also be used as surface-active auxiliaries and additives (K-2). 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 typically used in amounts of 0.01 to 5 parts by weight, based on 100 parts by weight of the total amount of components (J-1) and (J-2). 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, 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 auxiliaries and additives (K-2) 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.

[0112] Water can be used as an optional blowing agent (E), which reacts in situ with the organic polyisocyanates or with the prepolymers containing isocyanate groups to form carbon dioxide and amino groups, which in turn react with other isocyanate groups to form urea groups and act as a chain extender. 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 wt. %, based on the weight of components (J1), (J-2), (K1), and (K-2).

[0113] As blowing agents (E), instead of water or preferably in combination with water, gases or highly volatile inorganic or organic substances which evaporate under the influence of the exothermic polyaddition reaction and advantageously have a boiling point under normal pressure in the range from -40 to 120 °C, preferably from 10 to 90 °C, can also be used as physical blowing agents. 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 halogenated olefins (so-called HFOs or HCFOs) such as trans-1,3,3,3-tetrafluoropropene or trans-l-chloro-3,3,3-trifluoropropene, and unsubstituted alkanes such as butane, n-pentane, isopentane, cyclopentane, hexane, heptane or diethyl ether.These propellants can also be used as mixtures. Suitable inorganic propellants include air, CO2, or N2O. A propellant effect can also be achieved by adding compounds that decompose at temperatures above room temperature, releasing gases such as 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. 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 507-510 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.

[0114] The appropriate amount of solid blowing agents, low-boiling liquids or gases to be used, 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 PUR material density and the amount of water used. The required amounts can easily be determined experimentally. Satisfactory results are usually achieved with solids amounts of 0.5 to 35 parts by weight, preferably 2 to 15 parts by weight, liquid amounts of 1 to 30 parts by weight, preferably 3 to 18 parts by weight and / or gas amounts of 0.01 to 80 parts by weight, preferably 10 to 35 parts by weight, in each case based on the weight of the structural components (J-1), (J-2) and (M). The gas loading with e.g. B. Air, carbon dioxide, nitrogen and / or helium can be introduced either via the formulation components (Jl), (J-2), (Kl) and (K-2) or via the polyisocyanate as component (M) or.via components (Jl), (J-2), (Kl) and (K-2) on the one hand and component (M) on the other hand.

[0115] Suitable polyisocyanates (M) 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 having 2-18, preferably 6-10 C atoms, a cycloaliphatic hydrocarbon radical having 4-15, preferably 5-10 C atoms, an aromatic hydrocarbon radical having 6-15, preferably 6-13 C atoms, or an araliphatic hydrocarbon radical having 8-15, preferably 8-13 C atoms. Suitable polyisocyanates are, for example:Ethylene diisocyanate, 1,4-tetramethylene 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, pcrhydro-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-toluene 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).

[0116] 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 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.

[0117] 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.

[0118] Preferred polyisocyanates are those that are readily available industrially, e.g., 2,4- and 2,6-tolylene diisocyanate and any mixtures of these isomers ("TDI"), polyphenyl polymethylene 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 2,4- and / or 2,6-tolylene diisocyanate or from 4,4'- and / or 2,4'-diphenylmethane diisocyanate. Naphthylene 1,5-diisocyanate and mixtures of the above-mentioned polyisocyanates are also well suited.It is also possible to use prepolymers containing isocyanate groups, which are obtainable by reacting a portion or the entire amount of the hydroxyl-containing compound (A) to be used according to the invention and / or a portion or the entire amount of the isocyanate-reactive components described above, optionally to be admixed with the hydroxyl-containing compound (A) to be used according to the invention, with at least one aromatic di- or polyisocyanate from the group TDI, MDI, DIBDI, NDI, 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 0.05 to 40.0 wt. %.According to a preferred embodiment, the prepolymers containing isocyanate groups are prepared by reacting exclusively higher molecular weight polyhydroxyl compounds, i.e. the hydroxyl group-containing compound (A) to be used according to the invention, and / or polyetherester polyols, polyether polyols, polyester polyols or polycarbonate polyols with the polyisocyanates, preferably 4,4'-MDI, 2,4-TDI and / or 1,5 NDI.

[0119] 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 later to produce the PUR materials.

[0120] In one embodiment of the invention, the polyisocyanate (M) is one or more compounds and is selected from the group consisting of 2,4- and 2,6-tolylene diisocyanate, 4,4'- and 2,4'- and 2,2'-diphenylmethane diisocyanate and polyphenylpolymethylene polyisocyanate, preferably 2,4- and 2,6-tolylene diisocyanate.

[0121] To produce polyurethane (I), the ratio of isocyanate groups in the polyisocyanates (M) to the isocyanate-reactive hydrogens in components (J1), (J-2), (L), (K1), and (K-2) can be varied widely. Typical ratios are 0.9:1 to 6:1.

[0122] The polyurethanes (I) according to the invention can be prepared by the processes described in the literature, e.g., the one-shot or prepolymer process, using mixing devices known in principle to those skilled in the art. The hydroxyl-containing compound (A) preparable according to the invention can be processed as component (J1), optionally together with the isocyanate-reactive component (J-2), with the polyisocyanate (M) and optionally used blowing agent (L) using conventional low-pressure or high-pressure processing machines, in particular to produce flexible polyurethane foams, which are used, for example, in the manufacture of automotive seats, upholstered furniture, and mattresses.The hydroxyl-containing compound (A) according to the invention as component (J1) can be fed into the mechanical mixing unit either as a single component or as part of a pre-prepared formulation together with components (J-2), (K), and (L), if present, and optionally component (M). Its low viscosity proves particularly advantageous for the mechanical processing of the hydroxyl-containing compound (A) according to the invention.

[0123] The invention also relates to a polyurethane (I), preferably a polyurethane foam (I-1) or a compact polyurethane (I-2), obtainable by the process according to the invention.

[0124] In one embodiment of the invention, the polyurethane (I), preferably the polyurethane foam (I-1) or the compact polyurethane (I-2), is sulfur-free.

[0125] In one embodiment of the invention, the polyurethane (I), preferably the polyurethane foam (1-1) or the compact polyurethane (1-2) contains oximic urethane bonds, wherein the oximic urethane bonds are formed by reacting the hydroxyl group-containing compound (A) containing oximic hydroxyl groups with the isocyanate groups of the polyisocyanate as component (M).In a preferred embodiment of the invention, the polyurethane (I), preferably the polyurethane foam (1-1) or the compact polyurethane (1-2), is sulfur-free and the calculated proportion of the oximic urethane bonds in the polyurethane (I), preferably in the polyurethane foam (1-1) or in the compact polyurethane (1-2), is from 20 mol% to 100 mol%, preferably from 25 mol% to 100 mol%, particularly preferably from 30 mol% to 100 mol%, and very particularly preferably from 35 mol% to 100 mol%, based on the sum of all urethane bonds of the polyurethane (I), preferably the polyurethane foam (1-1) or the compact polyurethane (1-2). The invention also provides for the use of the hydroxyl group-containing compound (A) according to the invention or the hydroxyl group-containing compound (A) obtainable by the process according to the invention for facilitating the cleavage of urethane bonds in a process for recycling a polyurethane.

[0126] The invention also provides a process for producing a polyurethane (N) comprising a thermal treatment or an enzymatic treatment, preferably a thermal treatment, of the polyurethane (I) according to the invention, preferably the polyurethane foam (1-1) or the compact polyurethane (1-2) obtained by the process according to the invention.

[0127] In one embodiment of the invention, the thermal treatment is carried out at a temperature T(N) of 100 °C to 220 °C, preferably of 130 °C to 200 °C.

[0128] In one embodiment of the invention, the thermal treatment is carried out at a pressure p(N) of 50 bar to 300 bar, preferably of 80 bar to 200 bar.

[0129] In one embodiment of the invention, the thermal treatment is carried out in a reaction time t(N) of 0.1 min to 20 min, preferably of 0.2 min to 15 min.

[0130] In one embodiment of the invention, the thermal treatment takes place in a co-rotating multi-screw extruder, such as a twin-screw or quadruple-screw extruder, a ring extruder, a co-kneader, or a planetary roller extruder, or in rotor-stator systems. Other suitable devices are single- or twin-screw large-volume kneaders. The large-volume twin-screw kneaders can be co-rotating or counter-rotating. Examples of large-volume kneaders include CRP (von List Technology AG), Reacom (Buss-SMS-Canzler GmbH), Reasil (Buss-SMS-Canzler GmbH), and KRC Kneter (Kurimoto, Ltd).

[0131] In one embodiment of the invention, the polyurethane (N) is a thermoplastic polyurethane (N-1).

[0132] The invention also relates to a polyurethane (N), preferably a thermoplastic polyurethane (Nl), obtainable by the process according to the invention.

[0133] In one embodiment of the invention, the polyurethane (N), preferably the thermoplastic polyurethane (Nl), is sulfur-free.

[0134] In one embodiment of the invention, the polyurethane (N), preferably the thermoplastic polyurethane (N1), contains no oximic urethane bonds. In a preferred embodiment of the invention, the polyurethane (N), preferably the thermoplastic polyurethane (N1), contains oximic hydroxyl groups.

[0135] In an alternative embodiment, the polyurethane (N), preferably the thermoplastic polyurethane (N1), contains oximic urethane bonds, wherein the proportion of oximic urethane bonds, based on the sum of all urethane bonds of the polyurethane (N), preferably the thermoplastic polyurethane (N1), is lower than for the polyurethane (I), preferably the polyurethane foam (I-1) or the compact polyurethane (I-2). The proportion of oximic urethane bonds is preferably determined using an IR method, with the skilled person selecting a suitable IR method based on their specialist knowledge.

[0136] In a preferred embodiment of the invention, the proportion of oximic urethane bonds, based on the sum of all urethane bonds of the polyurethane (N), preferably of the thermoplastic polyurethane (Nl), is lower than in the polyurethane (I), wherein the polyurethane (N), preferably the thermoplastic polyurethane (Nl) contains oximic hydroxyl groups.

[0137] The invention also relates to a process for producing a polyurethane (O) by reacting the polyurethane (N) according to the invention, preferably the thermoplastic polyurethane (Nl), comprising the steps:

[0138] A) Optional mechanical comminution of the polyurethane (N), preferably the thermoplastic polyurethane (Nl),

[0139] B) Thermal treatment of the polyurethane (N), preferably the thermoplastic polyurethane (Nl) at a temperature T(O), optionally with addition of the catalyst (Kl) and / or optionally with addition of auxiliary and additive (K-2), wherein preferably: T(O) < T(N).

[0140] In one embodiment of the invention, the temperature T(O) is lower than the temperature T(N).

[0141] In one embodiment of the invention, the thermal treatment is carried out at a temperature T(O) of 80 °C to 200 °C, preferably of 110 °C to 180 °C.

[0142] In one embodiment of the invention, the thermal treatment is carried out at a pressure p(O) of 50 bar to 300 bar, preferably 80 bar to 200 bar. In one embodiment of the invention, the thermal treatment is carried out within a reaction time t(O) of 0.1 min to 20 min, preferably 0.2 min to 15 min.

[0143] In one embodiment of the invention, the thermal treatment of the polyurethane (N), preferably the thermoplastic polyurethane (Nl), takes place in a co-rotating multi-screw extruder, such as a twin-screw or four-screw extruder, a ring extruder, a co-kneader, or a planetary roller extruder, or in rotor-stator systems. Other suitable devices are single- or twin-screw high-volume kneaders. The large-volume twin-screw kneaders can be co-rotating or counter-rotating. Examples of high-volume kneaders include CRP (von List Technology AG), Reacom (Buss-SMS-Canzler GmbH), Reasil (Buss-SMS-Canzler GmbH), and KRC Kneter (Kurimoto, Ltd).

[0144] The invention also relates to a polyurethane (O) obtainable by the process according to the invention.

[0145] In one embodiment of the invention, the polyurethane (O) is sulfur-free.

[0146] In one embodiment, the polyurethane (O) contains oximic urethane bonds, wherein the proportion of oximic urethane bonds relative to the sum of all urethane bonds of the polyurethane (O) is higher than for the polyurethane (N), preferably the thermoplastic polyurethane (N1). The proportion of oximic urethane bonds is preferably determined using an IR method, with the skilled person selecting a suitable IR method based on their specialist knowledge.

[0147] In a first embodiment, the invention relates to a hydroxyl group-containing compound (A), wherein at least some of the hydroxyl groups are oximic hydroxyl groups, wherein the hydroxyl group-containing compound (A) is composed of the elements carbon, hydrogen, oxygen and nitrogen, wherein the hydroxyl group-containing compound (A) has an OH number (determined by means of DIN 4629-2 (December 2016)) of 10 mg KOH / g to 600 mg KOH / g, preferably of 12 mg KOH / g to 500 mg KOH / g, and wherein the hydroxyl group-containing compound (A) contains oxypropylene units.

[0148] In a second embodiment, the invention relates to a hydroxyl group-containing compound (A) according to the first embodiment, wherein the hydroxyl group-containing compound (A) contains oxyethylene and oxypropylene units.

[0149] In a third embodiment, the invention relates to a hydroxyl group-containing compound (A) according to the first or second embodiment, wherein the hydroxyl group-containing compound (A) contains at least 3 directly consecutive oxypropylene units.

[0150] In a fourth embodiment, the invention relates to a hydroxyl-containing compound (A) according to any one of the first to third embodiments, wherein the calculated proportion of oximic hydroxyl groups is from 20 mol% to 100 mol%, preferably from 25 mol% to 100 mol%, particularly preferably from 30 mol% to 100 mol%, and very particularly preferably from 35 mol% to 100 mol%, based on the sum of all free hydroxyl groups of the hydroxyl-containing compound. In a fifth embodiment, the invention relates to a hydroxyl-containing compound (A) according to any one of the first to fourth embodiments, wherein the hydroxyl-containing compound has a calculated hydroxyl group functionality of from 1 to 8, preferably from 2 to 6, and particularly preferably from 2 to 4.

[0151] In a sixth embodiment, the invention relates to a process for preparing a hydroxyl group-containing compound (A), preferably the hydroxyl group-containing compound (A) according to any one of the first to fifth embodiments, comprising the steps: i) reacting a component (B) containing one or more aliphatic hydroxyl group(s) with a component (C) containing (C1) one or more hydroxyl group-reactive functional group(s) and (C2) one or more carbonyl group(s), optionally in the presence of a catalyst (D) to form an intermediate (E), and ii) reacting the intermediate (E) with hydroxylamine and / or salts of hydroxylamine, preferably hydroxylamine.

[0152] In a seventh embodiment, the invention relates to a process according to the sixth embodiment, wherein the hydroxyl group-containing compound (A) is composed of the elements carbon, hydrogen, oxygen and nitrogen.

[0153] In an eighth embodiment, the invention relates to a process according to the sixth or seventh embodiment, wherein the aliphatic hydroxyl groups of component (B) are primary and / or secondary hydroxyl groups.

[0154] In a ninth embodiment, the invention relates to a process according to one of the sixth to eighth embodiments, wherein component (B) is obtainable or preferably obtained by reacting an H-functional starter compound (F) with an alkylene oxide (G) in the presence of a catalyst (H).

[0155] In a tenth embodiment, the invention relates to a process of the ninth embodiment, wherein the H-functional starter compound (F) is an amine and / or an alcohol, preferably an alcohol.

[0156] In an eleventh embodiment, the invention relates to a process of the tenth embodiment, wherein the H-functional starter compound (F) does not contain any thiol groups.

[0157] In a twelfth embodiment, the invention relates to a process of any of the ninth to eleventh embodiments, wherein the H-functional starter compound (F) is composed of the elements carbon, hydrogen, oxygen and nitrogen.

[0158] In a thirteenth embodiment, the invention relates to a process according to any one of the ninth to twelfth embodiments, wherein the H-functional starter compound (F) is an alcohol, and the alcohol is one or more compounds and is selected from the group consisting of ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2-methylpropane-1,3-diol, neopentyl glycol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, glycerol, trimethylolpropane, a difunctional polyether polyol and a trifunctional polyether polyol.

[0159] In a fourteenth embodiment, the invention relates to a process according to any one of the ninth to thirteenth embodiments, wherein the alkylene oxide (G) is propylene oxide and / or ethylene oxide.

[0160] In a fifteenth embodiment, the invention relates to a process according to any one of the ninth to fourteenth embodiments, wherein a mixture of ethylene oxide and propylene oxide is used as alkylene oxide (G), and this mixture preferably comprises up to 75% by mass of ethylene oxide, more preferably up to 50% by mass of ethylene oxide and most preferably up to 30% by mass of ethylene oxide, based on the total mass of the mixture of ethylene oxide and propylene oxide.

[0161] In a sixteenth embodiment, the invention relates to a process according to any one of the ninth to fifteenth embodiments, wherein the catalyst (H) is a double metal cyanide (DMC) catalyst, an alkali metal hydroxide, an alkaline earth metal hydroxide and / or an amine, a Lewis acid or a Brønsted acid, preferably a double metal cyanide (DMC) catalyst or an alkali metal hydroxide.

[0162] In a seventeenth embodiment, the invention relates to a process according to any one of the ninth to sixteenth embodiments, wherein the hydroxyl group-reactive functional group of component (C) is a carboxylic acid group, a carboxylic acid chloride group or a carboxylic acid ester group, preferably a carboxylic acid group.

[0163] In an eighteenth embodiment, the invention relates to a process according to the seventeenth embodiment, wherein the hydroxyl group-reactive functional group of component (C) is a carboxylic acid group, and component (C) is one or more compounds and is selected from the group consisting of levulinic acid, acetoacetic acid, pyruvic acid, a-methyllevulinic acid, 3-methyl-4-oxopentanoic acid, 4-oxo-2-propylpentanoic acid, 2-acetyl-4-methylpentanoic acid, preferably levulinic acid, acetoacetic acid and pyruvic acid.

[0164] In a nineteenth embodiment, the invention relates to a process according to any of the sixth to eighteenth embodiments, wherein the catalyst (D) is one or more compounds selected from the group consisting of tin dichloride, tin dichloride dihydrate, tin(II) 2-ethylhexanoate, dibutyltin dilaurate, titanium tetrabutoxide, tetraisopropyl titanate; bismuth(III) neodecanoate; zinc(II) acetate; manganese(II) acetate; p-toluenesulfonic acid, preferably p-toluenesulfonic acid. In a twentieth embodiment, the invention relates to a hydroxyl-containing compound (A) obtainable by the process according to any of the sixth to nineteenth embodiments.

[0165] In a twenty-first embodiment, the invention relates to a process for producing a polyurethane (I), preferably a polyurethane foam (I-1) or a compact polyurethane (I-2) by reacting the components

[0166] (J) comprising (Jl) the hydroxyl group-containing compound (A) according to any one of the first to fifth embodiments or the hydroxyl group-containing compound (A) obtainable by the process according to any one of the sixth to twentieth embodiments,

[0167] (J-2) optionally an isocyanate-reactive component

[0168] (K) where appropriate

[0169] (Cl) catalyst, and / or

[0170] (K-2) Auxiliary and additive substance

[0171] (L) where applicable

[0172] (L) a propellant, preferably water, with

[0173] (M) a polyisocyanate.

[0174] In a twenty-second embodiment, the invention relates to a process according to the twenty-first embodiment, wherein the polyoxyalkylene polyol (J-2) is polyester polyol, a polycarbonate polyol, a polyether carbonate polyol, a polyester carbonate polyol, a polyether ester carbonate polyol and / or a low molecular weight chain extender and / or crosslinking agent having OH numbers or NH numbers of 6 to 1870 mg KOH / g.

[0175] In a twenty-third embodiment, the invention relates to a process according to the twenty-first or twenty-second embodiment, wherein water is used as blowing agent (L) to form the polyurethane foam (1-1).

[0176] In a twenty-fourth embodiment, the invention relates to a process according to any one of the twenty-first to twenty-third embodiments, wherein the polyisocyanate (M) is one or more compounds and is selected from the group consisting of 2,4- and 2,6-tolylene diisocyanate, 4,4'- and 2,4'- and 2,2'-diphenylmethane diisocyanate and polyphenylpolymethylene polyisocyanate, preferably 2,4- and 2,6-tolylene diisocyanate.

[0177] In a twenty-fifth embodiment, the invention relates to a polyurethane (I), preferably polyurethane foam (1-1) or compact polyurethane (1-2), obtainable by the process according to any of the twenty-first to twenty-fourth embodiments.

[0178] In a twenty-sixth embodiment, the invention relates to a polyurethane (I) according to the twenty-fifth embodiment, wherein the polyurethane (I), preferably the polyurethane foam (1-1) or the compact polyurethane (1-2), is sulfur-free and the calculated proportion of the oximic urethane bonds in the polyurethane (I), preferably in the polyurethane foam (1-1) or in the compact polyurethane (1-2), is from 20 mol% to 100 mol%, preferably from 25 mol% to 100 mol%, particularly preferably from 30 mol% to 100 mol%, and very particularly preferably from 35 mol% to 100 mol%, based on the sum of all urethane bonds of the polyurethane (I), preferably of the polyurethane foam (1-1) or of the compact polyurethane (1-2).

[0179] In a twenty-seventh embodiment, the invention relates to a use of the hydroxyl group-containing compound (A) according to any one of the first to fifth embodiments or the hydroxyl group-containing compound (A) obtainable by the process according to any one of the sixth to nineteenth embodiments for facilitating the cleavage of urethane bonds in a process for recycling a polyurethane.

[0180] In a twenty-eighth embodiment, the invention relates to a process for producing a polyurethane (N) comprising a thermal treatment or an enzymatic treatment, preferably a thermal treatment, of the polyurethane (I), preferably the polyurethane foam (1-1) or the compact polyurethane (1-2) according to the twenty-sixth or twenty-seventh embodiment or obtained by the process according to one of the twenty-first to twenty-fifth embodiments.

[0181] In a twenty-ninth embodiment, the invention relates to a process according to the twenty-eighth embodiment, wherein the thermal treatment is carried out at a temperature T(N) of 100 °C to 220 °C, preferably of 130 °C to 200 °C.

[0182] In a thirtieth embodiment, the invention relates to a process according to the twenty-eighth or twenty-ninth embodiment, wherein the thermal treatment is carried out at a pressure p(N) of 50 bar to 300 bar, preferably of 80 bar to 200 bar.

[0183] In a thirty-first embodiment, the invention relates to a process according to one of the twenty-eighth to thirtieth embodiments, wherein the thermal treatment is carried out in a reaction time t(N) of 0.1 min to 20 min, preferably of 0.2 min to 15 min.

[0184] In a thirty-second embodiment, the invention relates to a process according to any one of the twenty-eighth to thirty-first embodiments, wherein the thermal treatment is carried out in a co-rotating multi-screw extruder, such as a twin-screw or a four-screw extruder or a ring extruder, a co-kneader or a planetary roller extruder or in rotor-stator systems.

[0185] In a thirty-third embodiment, the invention relates to a process according to any one of the twenty-eighth to thirty-second embodiments, wherein the polyurethane (N) is a thermoplastic polyurethane (Nl).

[0186] In a thirty-fourth embodiment, the invention relates to a polyurethane (N), preferably a thermoplastic polyurethane (Nl) obtainable by the process according to one of the twenty-eighth to thirty-third embodiments.

[0187] In a thirty-fifth embodiment, the invention relates to a polyurethane (N), preferably a thermoplastic polyurethane (Nl) according to the thirty-fourth embodiment, wherein the polyurethane (N), preferably the thermoplastic polyurethane (Nl), is sulfur-free.

[0188] In a thirty-sixth embodiment, the invention relates to a polyurethane (N), preferably a thermoplastic polyurethane (N1) according to the thirty-fourth or thirty-fifth embodiment, wherein the polyurethane (N), preferably the thermoplastic polyurethane (N1), contains no oximic urethane bonds. In a thirty-seventh embodiment, the invention relates to a polyurethane (N), preferably a thermoplastic polyurethane (N1) according to the thirty-fourth or thirty-fifth embodiment, wherein the polyurethane (N), preferably the thermoplastic polyurethane (N1), contains oximic urethane bonds, wherein the proportion of oximic urethane bonds, based on the sum of all urethane bonds of the polyurethane (N), preferably of the thermoplastic polyurethane (N1), is lower than for the polyurethane (I), preferably the polyurethane foam (I-1) or the compact polyurethane (I-2).

[0189] In a thirty-eighth embodiment, the invention relates to a polyurethane (N), preferably the thermoplastic polyurethane (Nl) according to the thirty-seventh embodiment, wherein the polyurethane (N), preferably the thermoplastic polyurethane (Nl) contains oximic hydroxyl groups.

[0190] In a thirty-ninth embodiment, the invention relates to a process for producing a polyurethane (O) by reacting the polyurethane (N), preferably the thermoplastic polyurethane (Nl) according to one of the thirty-fourth to thirty-eighth embodiments, comprising the steps:

[0191] A) Optional mechanical comminution of the polyurethane (N), preferably the thermoplastic polyurethane (Nl),

[0192] B) Thermal treatment of the polyurethane (N), preferably the thermoplastic polyurethane (Nl) at a temperature T(O), optionally with addition of a catalyst (Kl) and / or optionally with addition of auxiliaries and additives (K-2) ), wherein preferably: T(O) < T(N).

[0193] In a fortieth embodiment, the invention relates to a method according to the thirty-ninth embodiment, wherein the temperature T(O) is lower than the temperature T(N).

[0194] In a forty-first embodiment, the invention relates to a process according to the thirty-ninth or fortieth embodiment, wherein the thermal treatment is carried out at a temperature T(O) of 80 °C to 200 °C, preferably of 110 °C to 180 °C.

[0195] In a forty-second embodiment, the invention relates to a process according to one of the thirty-ninth to forty-first embodiments, wherein the thermal treatment is carried out at a pressure p(O) of 50 bar to 300 bar, preferably of 80 bar to 200 bar.

[0196] In a forty-second embodiment, the invention relates to a process according to the thirty-ninth or forty-first embodiment, wherein the thermal treatment is carried out in a reaction time t(O) of 0.1 min to 20 min, preferably of 0.2 min to 15 min.

[0197] In a forty-third embodiment, the invention relates to a process according to the thirty-ninth or forty-second embodiment, wherein the thermal treatment is carried out in a co-rotating multi-screw extruder, such as a twin-screw or four-screw extruder or a ring extruder, a co-kneader or a planetary roller extruder, or in rotor-stator systems. In a forty-fourth embodiment, the invention relates to a polyurethane (O) obtainable by the process according to any of the thirty-ninth to forty-third embodiments.

[0198] In a forty-fifth embodiment, the invention relates to a polyurethane (O) according to any one of the forty-fourth embodiments, wherein the proportion of oximic urethane bonds relative to the sum of all urethane bonds of the polyurethane (O) is higher than for the polyurethane (N), preferably the thermoplastic polyurethane (Nl).

[0199] Examples

[0200] Methods

[0201] OH number: The OH numbers (hydroxyl numbers) were determined according to the provisions of DIN 4629-2 (December 2016).

[0202] Viscosity: The viscosities were determined using a rotational viscometer (Physica MCR 72, manufacturer: Anton Paar) according to DIN 53019-1 (September 2008).

[0203] Acid number: The acid number was determined according to DIN EN ISO 2114 (November 2006).

[0204] NMR: The ('H- and 13 C-)NMR spectra were recorded on a Broker AV III HD 600 NMR spectrometer according to DIN EN ISO / IEC 17025. CDCh was used as solvent.

[0205] Dynamic Mechanical Analysis (DMA): The DMA measurements were performed on an Anton Paar MCR 702e space with the CTD600 convection oven. All experiments were conducted under a nitrogen atmosphere and compression, with a strain amplitude of 0.5% and a constant force of 1 or 2 N at a frequency of 1 Hz. Measurements were performed on cylindrical specimens with a diameter of 16 mm and a height of 9 mm. For each specimen, two different types of experiments with different temperature profiles were performed:

[0206] 1) Continuous heating up to a maximum of 250 °C at a heating rate of 2 K / min. Measurements were previously interrupted when the deformation limit of the measuring device was reached below 250 °C.

[0207] 2) Temperature hysteresis with a heating rate of 2 K / min up to a maximum temperature (TH) in the range of the softening temperature determined by Experiment 1. The temperature TH was held for 5 min, then the sample was cooled back to a temperature TL and held for 5 min before being heated back to TH. These cycles were repeated several times for stable samples.

[0208] By means of an experiment according to temperature profile 1), the softening temperature of the polyurethanes (I) was determined from the intersection point of the tangent to the extended base line and the tangent at the steepest point of the decrease of the tensile storage modulus.

[0209] By experimenting according to temperature profile 2), insights into recyclability can be gained.

[0210] A: Preparation of compounds (A) containing oximic hydroxyl groups: Raw materials:

[0211] Arcol® Polyol 1104: Trifunctional polyether polyol based on glycerol with an OH number of 55.5 mg KOH / g obtained by polymerization with 100 wt.% propylene oxide.

[0212] Arcol® Polyol 1108: Trifunctional polyether polyol based on glycerol with an OH number of 48 mg KOH / g obtained by copolymerization of 12 wt.% ethylene oxide with 88 wt.% propylene oxide.

[0213] Arcol® Polyol 1004: Bifunctional polyether polyol based on propylene glycol with an OH number of 260 mg KOH / g obtained by polymerization with 100 wt.% propylene oxide.

[0214] Arcol® Polyol 1030: Trifunctional polyether polyol based on glycerol with an OH number of 400 mg KOH / g obtained by polymerization with 100 wt.% propylene oxide.

[0215] Component (C): Levulinic acid: 98%, Sigma-Aldrich.

[0216] Catalyst (D): p-Toluenesulfonic acid monohydrate: Reagent Plus®, >98%, Sigma-Aldrich.

[0217] Hydroxylamine solution: 50 wt% in water, Sigma-Aldrich.

[0218] Example 1

[0219] Step (i) — Preparation of intermediate (E) by esterification of component (B) with component (C):

[0220] In a 1 L three-neck flask equipped with a precision glass stirrer, water separator, and thermocouple, 300 g of Arcol® Polyol 1104 (component (B)), 14.8 g of levulinic acid (component (C)), and 5000 ppm of p-toluenesulfonic acid (catalyst (D)) were dissolved in 350 mL of xylene. The reaction mixture was heated to reflux until the calculated amount of water (2.3 mL) was distilled, corresponding to a 42% conversion of the aliphatic OH groups of Arcol® Polyol 1104 through esterification with levulinic acid. The catalyst (p-toluenesulfonic acid) was removed from the organic phase by washing with a saturated sodium chloride solution (75 mL), and finally, the xylene solvent was distilled off.

[0221] The obtained product (Intermediate (E)) has an OH number of 28.1 mg KOH / g.

[0222] In the 'H NMR spectrum, the CH signal of the free secondary OH group of the product (intermediate (E)) is detected at 3.92 ppm and the esterified CH signal of the secondary OH group at 5.01 ppm. The molar ratio of these two signals, normalized to 3, is:

[0223] CH-OH 1.73

[0224] CH esterified 1.27.

[0225] In the 13 In the C-NMR spectrum, the two carbonyl carbon atoms of the esterified levulinic acid (component (C)) are detected with the following signals:

[0226] Ester group: 172.2 ppm

[0227] Keto group: 206.5 ppm.

[0228] Step (ii) — Reaction of intermediate (E) with hydroxylamine to form compound (A): 120 g of the esterified polyether polyol obtained in step (i) (intermediate (E)) were initially charged into a 500 mL round-bottom flask and dissolved in 90 mL ethanol. The reaction mixture was cooled using an ice bath, and then the stoichiometric amount of hydroxylamine (3.4 g of a 50 wt% aqueous solution) with respect to the hydroxyl groups esterified with levulinic acid was slowly added. The reaction mixture was then warmed to room temperature and stirred for 24 h. After distillation of the solvent, the desired polyether polyol (compound (A)) with 42% oximic and 58% aliphatic OH groups (calculated and determined experimentally) was obtained without further workup. OH number: 54.7 mg KOH / g.

[0229] In the 13In the C NMR spectrum, the signal of the carbonyl carbon atom of the ketone at 206.5 ppm is no longer detectable. The newly formed carbon atom of the oxime group can be detected by two new resonances at 155.2 and 156.2 ppm due to the formation of two configurational isomers. The signals of the carbonyl carbon atoms of the ester group are detected in the range of 172.2–172.4 ppm.

[0230] Example 2

[0231] Step (i) — Preparation of intermediate (E) by esterification of component (B) with component (C):

[0232] In a 2 L three-neck flask equipped with a precision glass stirrer, water separator, and thermocouple, 500 g of Arcol® Polyol 1108 (component (B)), 24.7 g of levulinic acid (component (C)), and 3000 ppm of p-toluenesulfonic acid (catalyst (D)) were dissolved in 580 mL of toluene. The reaction mixture was heated to reflux until the calculated amount of water (3.8 mL) was distilled, corresponding to a 50% conversion of the aliphatic OH groups of Arcol® Polyol 1108 through esterification with levulinic acid. After removal of the solvent, an acid number of 0.44 mg KOH / g was measured. The polyol (intermediate (E)) was neutralized with a stoichiometric amount of KOH (aqueous solution), and the resulting salt was filtered off. OH number: 24.8 mg KOH / g.

[0233] Step (ii) — Reaction of intermediate (E) with hydroxylamine to compound (A):

[0234] In a 500 mL round-bottom flask, 285 g of the esterified polyether polyol obtained in step (i) (intermediate (E)) were initially charged and dissolved in 140 mL of ethanol. The reaction mixture was cooled using an ice bath, and then the stoichiometric amount of hydroxylamine (7.7 g of a 50 wt% aqueous solution) with respect to the hydroxyl groups esterified with levulinic acid was slowly added. The reaction mixture was then warmed to room temperature and stirred for 24 h. After distillation of the ethanol solvent, the desired polyether polyol (compound (A)) with 50% oximic and 50% aliphatic OH groups (calculated) was obtained without further workup. OH number: 48.0 mg KOH / g.

[0235] Example 3 Step (i) - Preparation of intermediate (E) by esterification of component (B) with component (C):

[0236] In a 1 L three-necked flask equipped with a precision glass stirrer, water separator, and thermocouple, 350 g of Arcol® Polyol 1108 (component (B)), 25.9 g of levulinic acid (component (C)), and 5000 ppm of p-toluenesulfonic acid (catalyst (D)) were dissolved in 400 mL of toluene. The reaction mixture was heated to reflux until the calculated amount of water (4.0 mL) was distilled, corresponding to a 75% conversion of the aliphatic OH groups of Arcol® Polyol 1108 through esterification with levulinic acid. After removal of the toluene solvent, an acid number of 3.67 mg KOH / g was measured. The polyol (intermediate (E)) was neutralized with a stoichiometric amount of KOH (aqueous solution), and the resulting salt was filtered off.

[0237] Step (ii) — Reaction of intermediate (E) with hydroxylamine to compound (A):

[0238] In a 500 mL round-bottom flask, 280 g of the esterified polyether polyol obtained in step (i) (intermediate (E)) were initially charged and dissolved in 140 mL of ethanol. The reaction mixture was cooled using an ice bath, and then the stoichiometric amount of hydroxylamine (11.1 g of a 50 wt% aqueous solution) with respect to the hydroxyl groups esterified with levulinic acid was slowly added. The reaction mixture was then warmed to room temperature and stirred for 24 h. After distillation of the ethanol solvent, the desired polyether polyol (compound (A)) with 75% oximic and 25% aliphatic OH groups (calculated) was obtained without further workup. OH number: 47.2 mg KOH / g.

[0239] Example 4

[0240] Step (i) — Preparation of intermediate (E) by esterification of component (B) with component (C):

[0241] In a 2 L three-neck flask equipped with a precision glass stirrer, water separator, and thermocouple, 800 g of Arcol® Polyol 1108 (component (B)), 95 g of levulinic acid (component (C)), and 5000 ppm of p-toluenesulfonic acid (catalyst (D)) were dissolved in 700 mL of toluene. The reaction mixture was heated to reflux until the calculated amount of water (12.2 mL) was distilled, corresponding to 100% conversion of the aliphatic OH groups of Arcol® Polyol 1108 through esterification with levulinic acid. After removal of the toluene solvent, an acid number of 12.43 mg KOH / g was measured. The polyol (intermediate (E)) was neutralized with a stoichiometric amount of KOH (aqueous solution), and the resulting salt was filtered off.

[0242] Step (ii) — Reaction of intermediate (E) with hydroxylamine to compound (A):

[0243] In a 2 L round-bottom flask, 701 g of the esterified polyether polyol obtained in step (i) (intermediate (E)) were initially charged and dissolved in 450 mL of ethanol. The reaction mixture was cooled using an ice bath, and then the stoichiometric amount of hydroxylamine (36.3 g of a 50 wt% aqueous solution) with respect to the hydroxyl groups esterified with levulinic acid was slowly added. The reaction mixture was then warmed to room temperature and stirred for 24 h. After distillation of the ethanol solvent, the desired polyether polyol (compound (A)) with 100% oximic and 0% aliphatic OH groups (calculated) was obtained without further workup. OH number: 46.6 mg KOH / g.

[0244] Example 5

[0245] Step (i) - Preparation of intermediate (E) by esterification of component (B) with component

[0246] In a 1 L three-necked flask equipped with a precision glass stirrer, water separator, and thermocouple, 400 g of Arcol® Polyol 1004 (component (B)), 107.6 g of levulinic acid (component (C)), and 1000 ppm of p-toluenesulfonic acid (catalyst (D)) were dissolved in 300 mL of xylene. The reaction mixture was heated to reflux until the calculated amount of water (16.7 mL) was distilled, corresponding to a 50% conversion of the aliphatic OH groups of Arcol® Polyol 1004 through esterification with levulinic acid. After removing the xylene solvent, an acid number of 1.60 mg KOH / g was measured. The polyol (intermediate (E)) was neutralized with a stoichiometric amount of KOH (aqueous solution), and the resulting salt was filtered off.

[0247] Step (ii) — Reaction of intermediate (E) with hydroxylamine to compound (A):

[0248] In a 1 L round-bottom flask, 395 g of the esterified polyether polyol obtained in step (i) (intermediate (E)) were initially charged and dissolved in 200 mL of ethanol. The reaction mixture was cooled using an ice bath, and then the stoichiometric amount of hydroxylamine (49.2 g of a 50 wt% aqueous solution) with respect to the hydroxyl groups esterified with levulinic acid was slowly added. The reaction mixture was then warmed to room temperature and stirred for 24 h. After distillation of the ethanol solvent, the desired polyether polyol (compound (A)) with 50% oximic and 50% aliphatic OH groups (calculated) was obtained without further workup. OH number: 205.1 mg KOH / g.

[0249] Example 6

[0250] Step (i) — Preparation of intermediate (E) by esterification of component (B) with component (C):

[0251] In a 1 L three-necked flask equipped with a precision glass stirrer, water separator, and thermocouple, 400 g of Arcol® Polyol 1004 (component (B)), 215.3 g of levulinic acid (component (C)), and 10,000 ppm of p-toluenesulfonic acid (catalyst (D)) were dissolved in 300 mL of toluene. The reaction mixture was heated to reflux until the calculated amount of water (33.4 mL) was distilled, corresponding to 100% conversion of the aliphatic OH groups of Arcol® Polyol 1004 through esterification with levulinic acid. After removing the xylene solvent, an acid number of 2.99 mg KOH / g was measured. The polyol (intermediate (E)) was neutralized with a stoichiometric amount of KOH (aqueous solution), and the resulting salt was filtered off.

[0252] Step (ii) — Reaction of intermediate (E) with hydroxylamine to form compound (A): 400 g of the esterified polyether polyol obtained in step (i) (intermediate (E)) were initially charged into a 1 L round-bottom flask and dissolved in 200 mL of ethanol. The reaction mixture was cooled using an ice bath, and then the stoichiometric amount of hydroxylamine (84.1 g of a 50 wt% aqueous solution) with respect to the hydroxyl groups esterified with levulinic acid was slowly added. The reaction mixture was then warmed to room temperature and stirred for 24 h. After distillation of the ethanol solvent, the desired polyether polyol (compound (A)) with 100% oximic and 0% aliphatic OH groups (calculated) was obtained without further workup. OH number: 175.0 mg KOH / g.

[0253] Bl; Production of polyurethane foams (1-1)

[0254] Raw materials used

[0255] Synthesized polyether polyols (compounds (A)) from A

[0256] Polyisocyanate (M): Desmodur T80: Diisocyanate consisting of 80% 2,4-TDI and 20% 2,6-TDI Catalyst (Cl): Desmorapid SO: Tin octoate catalyst

[0257] Catalyst (Cl): NIAX Al Catalyst: Bis(2-Dimethylaminoethyl)ether

[0258] Auxiliary and additive (K-2): Tegostab BF 2370

[0259] General procedure:

[0260] In a 900 mL paper cup, 100 g of polyol (component (J)) with a total of 0.25 wt.% catalyst (K1), 0.8 wt.% stabilizer (K-2), and 3.5 wt.% chemical blowing agent (L), preferably water, were premixed for 25 seconds using a Pendraulik stirrer at approximately 2000 rpm. Subsequently, 44–46 g of polyisocyanate (M) (depending on the OH number of the polyol) were added and mixed for 7 seconds using a Pendraulik stirrer at approximately 2000 rpm. The reaction mixture was then immediately poured into a paper-lined wooden mold and, after the rise time, reacted in a heating cabinet at 90–100 °C for 10 minutes.

[0261] The recipes for the production of polyurethane foams (1-1) are summarized in Table 1.

[0262] Table 1:

[0263] In all tests (II) / AD, high-quality polyurethane flexible foams with a uniform cell structure were obtained. See: Comparative example

[0264] B-2: Production of compact polyurethanes (1-2)

[0265] Raw materials used

[0266] Synthesized polyether polyols (compounds (A)) from A

[0267] Polyisocyanate (M): Desmodur T80: Diisocyanate consisting of 80% 2,4-TDI and 20% 2,6-TDI

[0268] Catalyst (Kl): desmorapid SO: tin octoate catalyst

[0269] General procedure:

[0270] In a 200 mL beaker, 100 g of polyol (component (J)) was premixed with 0.5 wt.% catalyst (Kl) in a speed mixer for 30 seconds at 2500 rpm. Subsequently, 6.9–8.4 g of polyisocyanate (M) (depending on the OH number of the polyol) were added and mixed for a further 30 seconds at 2500 rpm in the speed mixer. The reaction mixture was then transferred to an aluminum mold and allowed to react at 70°C for 15–30 minutes.

[0271] The recipes for the production of the compact polyurethanes (1-2) are summarized in Table 2.

[0272] Table 2:

[0273] The resulting compact polyurethanes (1-2) were analyzed using dynamic mechanical analysis. The softening temperatures determined are listed in Table 2.

[0274] The results show that the polyurethane materials according to the invention (I-2 / CF) have lower softening temperatures than the polyurethane materials (I-2 / AB, comparison).

[0275] In particular, it is found that the polyurethane (I-2 / C) according to the invention, which was obtained using the polyol (J) from Example 1, has a significantly lower softening temperature (125°C) than the corresponding polyurethane (I-2 / A) (comparison), which was obtained using Arcol® 1104 (softening temperature 166°C).

[0276] In the same way, it is shown that the polyurethanes (I-2 / E) and (I-2 / F) according to the invention, which were obtained using the polyols (J) from Examples 3 and 4, have significantly lower softening temperatures (129 and 130°C) than the corresponding polyurethane (I-2 / B) (comparison), which was obtained using Arcol® 1108 (softening temperature 201°C).

[0277] C: Production of polyurethanes (N) by thermal treatment of polyurethane foams (I- 11

[0278] The extrusion tests were conducted in an MC 15 HAT micro-compounder (Xplore Instruments BV, The Netherlands). Tests were conducted at various temperatures (130, 160, 180, 200, and 220°C) to obtain the best temperature conditions for producing a compact and continuous extrudate strand. The temperature was kept constant throughout each experiment.

[0279] All tests were conducted according to the following procedure: The device was heated and held at the desired temperature for at least 30 minutes to eliminate possible fluctuations. The extruder's screw speed was then set to a constant 100 rpm, and the material was fed in flakes. This process took up to 2 minutes, depending on the foam and temperature. After complete filling, the material was held in the extruder for a further 10 minutes before being discharged. The quality of the polyurethane was measured by the appearance and durability of the resulting strand, as well as the ease of discharge.

[0280] Example Cl (according to the invention)

[0281] Under these conditions, the flexible foam from test (Il / C) resulted in a compact and continuous extrudate strand without any color change (see Figure 1).

[0282] Example C-2 (comparison example)

[0283] Under these conditions, the flexible foam from test (Il / A) (comparison) did not produce a continuous extrudate strand but only powdery fragments (see Figure 2).

Claims

Patent claims 1. A hydroxyl group-containing compound (A), wherein at least some of the hydroxyl groups are oximic hydroxyl groups, wherein the hydroxyl group-containing compound (A) is composed of the elements carbon, hydrogen, oxygen and nitrogen, wherein the hydroxyl group-containing compound (A) has an OH number of 10 mg KOH / g to 600 mg KOH / g, preferably of 12 mg KOH / g to 500 mg KOH / g, and wherein the hydroxyl group-containing compound (A) contains oxypropylene units.

2. The hydroxyl group-containing compound (A) according to claim 1, wherein the hydroxyl group-containing compound (A) contains at least 3 directly consecutive oxypropylene units.

3. Hydroxyl group-containing compound (A) according to claim 1 or 2, wherein the calculated proportion of the oximic hydroxyl groups is from 20 mol% to 100 mol%, preferably from 25 mol% to 100 mol%, particularly preferably from 30 mol% to 100 mol%, and very particularly preferably from 35 mol% to 100 mol%, based on the sum of all free hydroxyl groups of the hydroxyl group-containing compound.

4. Hydroxyl group-containing compound (A) according to any one of claims 1 to 3, wherein the hydroxyl group-containing compound has a calculated hydroxyl group functionality of 1 to 8, preferably of 2 to 6 and particularly preferably of 2 to 4.

5. A process for preparing a hydroxyl group-containing compound (A), preferably the hydroxyl group-containing compound (A) according to any one of claims 1 to 4, comprising the steps: i) reacting a component (B) containing one or more aliphatic hydroxyl group(s) with a component (C) containing (C1) one or more hydroxyl group-reactive functional group(s) and (C2) one or more carbonyl group(s), optionally in the presence of a catalyst (D) to form an intermediate (E), and ii) reacting the intermediate (E) with hydroxylamine and / or salts of hydroxylamine, preferably hydroxylamine.

6. The process according to claim 5, wherein component (B) is obtainable, preferably is obtained, by reacting an H-functional starter compound (F) with an alkylene oxide (G) in the presence of a catalyst (H).

7. The process according to claim 6, wherein the H-functional starter compound (F) is an amine and / or an alcohol, preferably an alcohol.

8. Process for the preparation of a polyurethane (I), preferably a polyurethane foam (I-1) or a compact polyurethane (I-2) by reacting the components (J) containing (Jl) the hydroxyl group-containing compound (A) according to any one of claims 1 to 4 or the hydroxyl group-containing compound (A) obtainable by the process according to any one of claims 5 to 7, (J-2) optionally an isocyanate-reactive component (K) where appropriate (Cl) catalyst, and / or (K-2) Auxiliary and additive substance (L) where applicable (L) a propellant, preferably water, with (M) a polyisocyanate.

9. Polyurethane (I), preferably polyurethane foam (I-1) or compact polyurethane (I-2), obtainable by the process according to claim 8.

10. Use of the hydroxyl group-containing compound (A) according to any one of claims 1 to 4 or the hydroxyl group-containing compound (A) obtainable by the process according to any one of claims 5 to 7 for facilitating the cleavage of urethane bonds in a process for recycling a polyurethane.

11. A process for producing a polyurethane (N), preferably a thermoplastic polyurethane (N1), comprising a thermal treatment or an enzymatic treatment, preferably a thermal treatment, of the polyurethane (I), preferably the polyurethane foam (I-1) or the compact polyurethane (I-2) according to claim 9 or obtained by the process according to claim 8.

12. The method according to claim 11, wherein the thermal treatment is carried out at a temperature T(N) of 100 °C to 220 °C.

13. Polyurethane (N), preferably a thermoplastic polyurethane (Nl) obtainable by the process according to claim 11 or 12.

14. A process for producing a polyurethane (O) by reacting the polyurethane (N), preferably the thermoplastic polyurethane (Nl) according to claim 13, comprising the steps: A) Optional mechanical comminution of the polyurethane (N), preferably the thermoplastic polyurethane (Nl), B) Thermal treatment of the polyurethane (N), preferably the thermoplastic polyurethane (Nl) at a temperature T(O), optionally with addition of the catalyst (Kl) and / or optionally with addition of auxiliary and additive (K-2), wherein preferably: T(O) < T(N).

15. Polyurethane (O) obtainable by the process according to claim 14.

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