Method for preparing a polyoxyalkylene polyol

Abstract

The invention relates to a method for preparing a polyoxyalkylene polyol comprising attaching an alkylene oxide (A) to an H-functional starter substance (B) in the presence of a basic catalyst (C) with the formation of an intermediate (D), followed by vacuum-treating the intermediate (D) at pressures of 1 mbara to 500 mbara with the formation of an intermediate (E). Then, an alkylene oxide (F) is attached to this intermediate (E) with the formation of an alkaline polyoxyalkylene polyol (H) and then water is added with the formation of a mixture (J) comprising a first phase (J-1) containing the polyoxyalkylene polyol and a second aqueous phase (J-2). Then, the second aqueous phase (J- 2) is separated from the first phase (J-1) containing the polyoxyalkylene polyol via gravitation. The addition of the alkylene oxide (A) ends before the vacuum treatment and the addition of the alkylene oxide (F) is not started until after the vacuum treatment has been completed.

Description

[0001] Process for producing a polyoxyalkylene polyol

[0002] The invention relates to a process for producing a polyoxyalkylene polyol, comprising the addition of an alkylene oxide (A) to an H-functional starter substance (B) in the presence of a basic catalyst (C) to form an intermediate (D), followed by vacuum treatment of the intermediate (D) at pressures of 1 mbara to 500 mbara to form an intermediate (E). Subsequently, an alkylene oxide (F) is added to this intermediate (E) to form an alkaline polyoxyalkylene polyol (H), and water is subsequently added to form a mixture (J) comprising a first phase (J1) containing the polyoxyalkylene polyol and a second, aqueous phase (J-2). Finally, the second, aqueous phase (J-2) is separated from the first phase (J1) containing the polyoxyalkylene polyol by gravity.Here, the addition of the alkylene oxide (A) is terminated before the vacuum treatment and the addition of the alkylene oxide (F) is only started after the vacuum treatment has been completed.

[0003] EP 3747929 A1 discloses a process for the purification of polyether polyols, wherein in a first step the basic polyether polyol is neutralized with an acid and then the resulting phases are separated.

[0004] DD 144 272 discloses a one- or two-stage process for the preparation of polyether polyols, wherein the proportion of unsaturated monofunctional components in the resulting polyol is to be significantly reduced.

[0005] US 3,823,145 discloses a process for purifying polyoxyalkylene ether polyols containing water-soluble catalyst residues, wherein organic solvents such as hexane or toluene and also water are added to the crude polyoxyalkylene ether polyol containing the water-soluble catalyst residues, forming a first organic phase containing the organic solvent and the polyether polyol and a second, aqueous phase containing the catalyst residues. Subsequently, phase separation and removal of the organic solvent take place to form the purified polyoxyalkylene ether polyol.

[0006] All prior art processes have in common that they are either complicated to carry out, for example, due to the addition of non-polar solvents to assist the phase separation process, or that the phase separation is slow or incomplete. The object of the present invention was therefore to provide an improved process that eliminates the described disadvantages of the prior art processes and is characterized in particular by an improved separation of an aqueous phase containing the catalyst residues from the polyoxyalkylene polyol phase. In addition to increasing process efficiency, this also makes it possible to reduce the content of organic contaminants in the wastewater without having to carry out technically complex, additional filtration processes.In addition, the addition of organic solvents during the purification process should ideally be avoided, as these must be separated from the polyoxyalkylene polyol and purified by distillation at a high energy expenditure.

[0007] Surprisingly, the object was achieved by a process for preparing a polyoxyalkylene polyol, preferably a polyether polyol, comprising the following steps: i) addition of an alkylene oxide (A) to an H-functional starter substance (B) in the presence of a basic catalyst (C) to form an intermediate (D), ii) vacuum treatment of the intermediate (D) at pressures of 1 mbara to 500 mbara, preferably from 2 mbara to 200 mbara, and particularly preferably from 2 mbara to 50 mbara to form an intermediate (E), iii) addition of an alkylene oxide (F) to the intermediate (E), optionally in the presence of a basic catalyst (G), to form an alkaline polyoxyalkylene polyol (H), preferably an alkaline polyether polyol (H1), iv) optional vacuum treatment of the alkaline polyoxyalkylene polyol (H), preferably the alkaline polyether polyol (Hl) at pressures from 1 mbara to 500 mbara, preferably from 2 mbara to 200 mbara,and particularly preferably from 2 mbara to 50 mbara, v) adding water and optionally an acid (I) to the alkaline polyoxyalkylene polyol (H), preferably to the alkaline polyether polyol (H1) to form a mixture (J) comprising a first phase (J1) containing the polyoxyalkylene polyol and a second, aqueous phase (J-2), vi) separating the second, aqueous phase (J-2) from the first phase (J1) containing the polyoxyalkylene polyol by gravity, wherein the addition of the alkylene oxide (A) in step i) is terminated before the vacuum treatment in step ii) and the addition of the alkylene oxide (F) begins only after the vacuum treatment in step ii) has been completed.

[0008] In the process according to the invention, polyoxyalkylene polyols are understood to be addition products of one or more alkylene oxides and optionally one or more comonomers such as CO2 and / or cyclic carboxylic anhydrides and / or cyclic esters such as lactones or lactide with one or more H-functional starter substances in the presence of a basic catalyst (C) and / or (G), wherein polyether polyols, polyether ester polyols, polycarbonate polyols, polyether carbonate polyols or polyether ester carbonate polyols, preferably polyether polyols, are obtainable.

[0009] In one embodiment of the invention, the polyoxyalkylene polyol, preferably the polyether polyol, has a hydroxyl number of 25 mg KOH / g to 100 mg KOH / g, preferably 28 mg KOH / g to 60 mg KOH / g, wherein the hydroxyl number was determined by means of the method DIN 53240-2 (2007-11) disclosed in the experimental part.

[0010] In one embodiment of the invention, the polyoxyalkylene polyol, preferably the polyether polyol, has a molar proportion of primary hydroxyl groups of > 50 mol% to < 100 mol%, wherein the molar proportion of primary hydroxyl groups is determined by NMR spectroscopy according to the method described in WO 2021 / 198054 A1.

[0011] In a preferred embodiment of the process according to the invention, the polyoxyalkylene polyol is a polyether polyol, wherein the polyether polyol is obtainable by addition of one or more alkylene oxides to one or more H-functional starter substances in the presence of a basic catalyst (C) and optionally a further catalyst (G) such as one or more amines, one or more alkyl metal hydrides or, particularly preferably, one or more alkali metal hydroxides.

[0012] The following embodiments of the invention, ie the process according to the invention but also the products obtainable by the process, can be combined with one another as desired, unless the technical context indicates otherwise.

[0013] The at least one alkylene oxide (A) used in the process according to the invention has 2 to 24 carbon atoms. The alkylene oxides (A) 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, C1-C24 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.

[0014] In the process according to the invention, propylene oxide or a mixture of ethylene oxide and propylene oxide is preferably used as the alkylene oxide (A). 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 of the alkylene oxide (A). Particular preference is given to using exclusively propylene oxide as the alkylene oxide (A), and to using 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, as the alkylene oxide (A). The alkylene oxides (A) 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 (A) to the reactor successively, thus allowing polyoxyalkylene chains with a block structure to be formed in step i). When metering several alkylene oxides (A), it is also possible to change the composition of the fed alkylene oxide stream continuously or instantaneously.

[0015] In the process according to the invention for the preparation of the polyoxyalkylene polyols, one or more H-functional starter substance(s) (B) are used.

[0016] Suitable H-functional starter substances (B), also called starters, can be 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 it yields methane by reaction with methylmagnesium iodide according to a process discovered by Zerewitinoff. Typical examples of compounds with Zerewitinoff-active hydrogen are compounds containing carboxyl, hydroxyl, amino, imino, or thiol groups as functional groups.

[0017] Particularly suitable groups with active H atoms for the alkoxylation are -OH and -NH2, -OH is very particularly preferred. As H-functional starter substance, for example, one or more compounds can be selected from the group comprising mono- or polyhydric alcohols, polyhydric amines, polyhydric thiols, amino alcohols, thioalcohols, hydroxyesters, 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), polyetherthiols, 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), Merginol® types (Hobum Oleochemicals GmbH), Sovermol® types (Cognis Deutschland GmbH & Co. KG) and Soyol®TM types (USSC Co.).

[0018] In a preferred embodiment of the process according to the invention, the H-functional starter substance (B) is a polyol, preferably a polyfunctional alcohol, a polyfunctional amine, a polyether polyol, and a polyether ester polyol, and particularly preferably a polyether polyol and / or a polyfunctional alcohol.

[0019] Suitable H-functional starter substances (B) 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-pentanediol, methylpentanediol (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 substance (B) for carrying out the process according to the invention.

[0020] 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 substances (B).

[0021] The H-functional starter substances (B) can also be selected from the substance class of polyether polyols, in particular from those with a number-average molecular weight (M n) in the range from 100 to 4000 g / mol. Preferred polyether polyols are those 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 as Desmophen® 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 homo-polyethylene oxides are, for example, the Pluriol® E brands from BASF SE, suitable homo-polypropylene oxides are, for example, the Pluriol® P brands from BASF SE, suitable mixed copolymers of ethylene oxide and propylene oxide are, for example, the Pluronic® PE or Pluriol® RPE brands from BASF SE.

[0022] The H-functional starter substances (B) 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 substances are used either individually or as a mixture of at least two H-functional starter substances.

[0023] In a preferred embodiment of the process according to the invention, the H-functional starter substances (B) 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.

[0024] According to the invention, basic catalysts (C) such as alkali metal hydrides, alkali metal carboxylates (for example those of monofunctional carboxylic acids), alkali metal hydroxides, or amines are used. Alkali metal alkoxylates (for example those of mono- or polyfunctional alcohols) can also be used with preference. Furthermore, alkali metal alkoxylates of polyfunctional polyoxyalkylene polyols are particularly preferably used as catalyst supports.

[0025] The latter can be obtained, for example, by prealkoxylating the H-functional starter substance (B) with a first portion (A1), preferably a small portion, of the alkylene oxide (A) in a step i-1) in the presence of an alkali metal hydride, an alkali metal carboxylate, and / or an alkali metal hydroxide as an embodiment of a basic catalyst (C), preferably an alkali metal hydroxide, particularly preferably sodium hydroxide and / or potassium hydroxide, optionally after dehydration, and then optionally adding further alkali metal hydride, further alkali metal carboxylate, or, preferably, further alkali metal hydroxide (Cl) and optionally dehydrating a further time. The alkali metal alkoxylates resulting from such a step i-1) are then reacted in step i-2) with a second portion (A-2) of the alkylene oxide (A) to form the intermediate (D).

[0026] In one embodiment of the process according to the invention, the basic catalyst (C) is an alkali metal hydroxide or an amine, preferably an alkali metal hydroxide.

[0027] An overview of amines suitable as catalysts for the process according to the invention has been provided by M. Ionescu 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-methylmorphol, unsubstituted imidazole, and / or alkyl-substituted imidazole derivatives can be used. However, the alkali metal hydroxides already mentioned (such as sodium hydroxide, potassium hydroxide, or cesium hydroxide) are particularly preferably used as basic catalysts in the process according to the invention. The alkali metal hydroxides can be used as solids or as highly concentrated aqueous solutions.

[0028] Sodium hydroxide and / or potassium hydroxide are very particularly preferably used as alkali metal hydroxide catalysts in the process according to the invention.

[0029] The basic catalysts (C) are generally used in an amount of 0.004 to 0.8 wt. %, preferably 0.004 to 0.5 wt. %, based on the amount of end product (i.e., the amount of polyoxyalkylene polyol to be produced, preferably the alkaline polyoxyalkylene polyol (H)). If alkali metal alkoxylates, preferably alkali metal alkoxylates of polyfunctional polyoxyalkylene polyols, are used, the amount of catalyst based on the amount of end product, preferably on the amount of alkaline polyoxyalkylene polyol (H), is calculated from the amount of catalyst present in the polyfunctional polyoxyalkylene polyol after production of the alkali metal alkoxylate, i.e., for example, the amount of alkali metal hydroxide contained therein.

[0030] If alkali metal hydroxides are used as catalysts, the water introduced upon addition of the aqueous alkali metal hydroxide solutions and the water formed during the reaction of the Zerewitinoff-active hydrogens of the H-functional compound (B) with the alkali metal hydroxide can also be separated off by a (optionally vacuum-assisted) distillation step before the start of the addition of the alkylene oxide (A) in order to prevent the potentially undesirable formation of polyoxyalkylenediols as a result of the reaction of the remaining water with the alkylene oxide (A). If an amine is present under the at least one H-functional starter compound (B), the addition of the catalyst to the reaction mixture can also be delayed, i.e., only after the addition of a certain amount of alkylene oxide to the catalyst-free reaction mixture.

[0031] In a preferred embodiment of the process according to the invention, the basic catalyst (C) or, for example, an alkali metal alkoxylate resulting from the reaction of a polyol as an H-functional compound (B) with the alkylene oxide (A) after step i) is not separated after this step i), so that catalyst (C) or its reaction product in step iii) also catalytically supports the addition of an alkylene oxide (F). In this preferred embodiment, the addition of a catalyst (G) different from catalyst (C) can generally be dispensed with.

[0032] In one embodiment of the process according to the invention, the intermediate (D) is obtainable by addition of the alkylene oxide (A) to the H-functional starter substance (B) in the presence of the basic catalyst (C), preferably the alkali metal hydroxide or the amine, particularly preferably the alkali metal hydroxide such as potassium hydroxide and / or sodium hydroxide.

[0033] In a further embodiment of the process according to the invention, the intermediate (D) is obtainable by addition of the alkylene oxide (A) to alkali metal alkoxylates of polyfunctional polyoxyalkylene polyols, which simultaneously act as catalyst supports.

[0034] According to the invention, the formation of the intermediate (E) takes place by vacuum treatment of the intermediate (D) at pressures of 1 mbara to 500 mbara, preferably at pressures of 2 mbara to 100 mbara, particularly preferably at pressures of 2 to 50 mbara in step ii).

[0035] For the process according to the invention, the at least one alkylene oxide (F) has 2 to 24 carbon atoms. The alkylene oxides (F) 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, C1-C24 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.

[0036] In a preferred embodiment of the process according to the invention, the alkylene oxide (F) is ethylene oxide or a mixture of ethylene oxide and propylene oxide containing at least 70% by mass of ethylene oxide, based on the total mass of the mixture of ethylene oxide and propylene oxide of the alkylene oxide (F). In a particularly preferred embodiment, the alkylene oxide (F) is ethylene oxide.

[0037] The alkylene oxides (F) 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 (F) to the reactor successively, thus making it possible to produce polyoxyalkylene chains with a block structure. When metering several alkylene oxides (F), it is possible to change the composition of the fed alkylene oxide stream continuously or instantaneously.

[0038] In a preferred embodiment of the process according to the invention, no further basic catalyst (G) is added in step iii).

[0039] In a less preferred embodiment of the process according to the invention, additional basic catalyst (G) is added in step iii).

[0040] In the process according to the invention, preference is given to using basic catalysts (G) such as, for example, alkali metal hydrides, alkali metal carboxylates (for example those of monofunctional carboxylic acids), alkali metal hydroxides, alkali metal alkoxides (for example those of monofunctional alcohols) or amines.

[0041] In one embodiment of the process according to the invention, the basic catalyst (G) is an alkali metal hydroxide or an amine, preferably an alkali metal hydroxide.

[0042] Particularly preferred basic catalysts (G) used in the process according to the invention are alkali metal hydroxides (such as sodium hydroxide, potassium hydroxide, or cesium hydroxide) or amines. The alkali metal hydroxides can be used as solids or as highly concentrated aqueous solutions.

[0043] Sodium hydroxide and / or potassium hydroxide are very particularly preferably used as alkali metal hydroxide catalysts in the process according to the invention.

[0044] In an extremely preferred embodiment of the process according to the invention, the basic catalyst (C) and the basic catalyst (G) are identical. Preferably, catalyst (C) and catalyst (G) are basic catalysts (Cl) and (Gl), and particularly preferably alkali metal hydroxides.

[0045] According to the invention, the alkaline polyoxyalkylene polyol (H), preferably the alkaline polyether polyol (H1), is formed by addition of the alkylene oxide (F) and optionally further comonomers to the intermediate (E), optionally in the presence of a basic catalyst (G), in step iii) of the process according to the invention.

[0046] The invention further provides the alkaline polyoxyalkylene polyol (H) obtainable by the process according to the invention. According to the invention, the alkaline polyether polyol (H1) is formed by addition of one or more alkylene oxides (F) to the intermediate (E), optionally in the presence of a basic catalyst (G), in step iii) of the process according to the invention.

[0047] A further object of the invention is the alkaline polyether polyol (H1) obtainable by the process according to the invention.

[0048] In one embodiment of the process according to the invention, the acid (I) is a mineral acid, a hydroxycarboxylic acid, a cyclic dicarboxylic anhydride, and / or an incompletely alkoxylated phosphorus oxoacid; preferably, the acid (I) is a mineral acid. Alternatively, carbon dioxide can be used as the acid (I) for the neutralization.

[0049] Preference is given to using inorganic mineral acids, particularly preferably phosphoric acid and / or sulfuric acid, with phosphoric acid and / or sulfuric acid being used in a particularly preferred embodiment as dilute, aqueous phosphoric acid and / or as dilute, aqueous sulfuric acid. In an alternative embodiment, the acid (I) is an organic acid, such as adipic acid, formic acid, and / or acetic acid.

[0050] According to the invention, the mixture (J) comprises a first phase (J1) containing the polyoxyalkylene polyol and a second, aqueous phase (J-2). In one embodiment of the process according to the invention, the alkaline polyoxyalkylene polyol (H), preferably the alkaline polyether polyol (H1), is neutralized by adding water and the acid (I) to form the mixture (J) comprising a first phase (J1) containing the polyoxyalkylene polyol and a second aqueous phase (J-2) containing a neutralization salt.

[0051] The invention further provides the mixture (J) comprising a first phase (J1) containing the polyoxyalkylene polyol and a second, aqueous phase (J-2), preferably containing the neutralization salt, obtainable by the process according to the invention.

[0052] According to the invention, in step i) the addition of the alkylene oxide (A) to the H-functional starter substance (B) optionally takes place in the presence of the basic catalyst (C) to form the intermediate (D).

[0053] In one embodiment of the process according to the invention, step i) is carried out at a temperature of 70 °C to 130 °C, preferably from 80 °C to 115 °C. The temperature can be varied during the alkylene oxide metering phase in step i) within the limits described: In order to achieve an optimal balance between high alkylene oxide conversion and low by-product formation when using sensitive H-functional compounds (B) (starter compounds), such as sucrose, alkoxylation can initially be carried out at low reaction temperatures in step i) (for example at 70 to 110 °C) and only when the H-functional starter substance (B) has been sufficiently converted (i.e. as soon as at least 50 wt. % of the H-functional starter substance (B) used has reacted with alkylene oxide at at least one Zerewitinoff-active hydrogen atom) can the reaction temperatures be increased (for example to 110 to 130 °C).

[0054] The temperature of the exothermic alkylene oxide addition reaction is maintained at the desired level by cooling. According to the state of the art for the design of polymerization reactors for exothermic reactions (e.g., Ullmann's Encyclopedia of Industrial Chemistry, Volume B4, page 167ff, 5th edition, 1992), such cooling is generally achieved via the reactor wall (e.g., double jacket, half-coil) and by means of additional heat exchanger surfaces arranged internally in the reactor and / or externally in the pumped circulation circuit, e.g., on cooling coils, cooling candles, plate-and-tube, or mixer heat exchangers. These should advantageously be designed to allow effective cooling even at the beginning of the metering phase, i.e., at low fill levels and / or in the presence of potentially heterogeneous reactor contents (e.g., in the presence of solid dispersions or suspensions).In one embodiment of the process according to the invention, step i) is carried out at a pressure of 0.001 bara to 10 bara, preferably of 0.01 bara to 7 bara.

[0055] In one embodiment of the process according to the invention, step i) comprises the following substeps: i-1) Addition of a first portion (A1) of the alkylene oxide (A) to the polyether polyol and / or the polyfunctional alcohol as H-functional starter substance (B) in the presence of the alkali metal hydride, the alkali metal carboxylate and / or the alkali metal hydroxide, preferably the alkali metal hydroxide, as basic catalyst (C) to form an alkali metal alkoxylate,

[0056] 1-2) Reaction of the alkali metal alkoxylate with a second portion (A-2) of the alkylene oxide (A) to form the intermediate (D).

[0057] In one embodiment of the process according to the invention, the substance fraction n(Al) of the first portion of the alkylene oxide (Al) added in step i-1) is from 6 mol% to 20 mol%, preferably from 8 mol% to 18 mol% and particularly preferably from 10 mol% to 16 mol%, based on the sum of the substance amounts of the first portion n(Al) and the second portion n(A-2).

[0058] In this case, further basic catalyst (Cl) such as alkali metal hydride, alkali metal carboxylate and / or alkali metal hydroxide, preferably alkali metal hydroxide, can be added to the alkali metal alkoxylate obtained in step i-1) before the further reaction in step i-2), and optionally dehydrated. Such dehydration processes are preferably carried out by treating the alkali metal alkoxylate obtained in step i-1) and admixed with further basic catalyst Cl at 80°C to 150°C and 500 mbara to 1 mbara for 10 minutes to 3 hours. In the process according to the invention, the addition of the alkylene oxide (A) in step i) is terminated before the vacuum treatment in step ii), and the addition of the alkylene oxide (F) is not commenced until after the vacuum treatment in step ii) has been completed.In one embodiment of the process according to the invention, after the addition of the alkylene oxide (A) in step i) has ended and before the vacuum treatment in step ii), the intermediate (D) is treated in a first post-reaction phase at a temperature of 80°C to 150°C, preferably from 80°C to 115°C, and a pressure of 0.01 bara to 10 bara, preferably from 0.1 bara to 7 bara. The first post-reaction phase preferably takes place over a period of 20 minutes to 300 minutes, preferably from 50 minutes to 200 minutes. In this first post-reaction phase, the amount of unreacted alkylene oxide (A) before the vacuum treatment in step ii) is to be reduced, which leads to improved process efficiency of the preparation process according to the invention due to higher alkylene oxide conversions and thus fewer alkylene oxide losses.

[0059] In a preferred embodiment of the process according to the invention, the first post-reaction phase can be carried out at a higher temperature than that at which the reaction in step i) took place. This can further increase the process efficiency described above.

[0060] In a preferred embodiment of the process according to the invention, no water and / or acid addition takes place between steps i) and ii). Adding water would increase the energy expenditure in step ii), because the evaporation enthalpy of the introduced water would also have to be absorbed in this step. Adding acid before step ii) would also be incompatible with the basic catalysts C) and, if applicable, G), since they would be deactivated by the acid.

[0061] According to the invention, in step ii) the vacuum treatment of the intermediate (D) is carried out at pressures of 1 mbara to 500 mbara, preferably of 2 mbara to 200 mbara, and particularly preferably of 2 mbara to 50 mbara to form an intermediate (E).

[0062] In one embodiment of the process according to the invention, the vacuum treatment in step ii) is carried out at temperatures of 20 °C to 200 °C, preferably at 50 °C to 160 °C, particularly preferably at 100 °C to 150 °C.

[0063] In a preferred embodiment of the process according to the invention, step ii) is carried out at a higher temperature than the reaction in step i).

[0064] In one embodiment of the process according to the invention, the vacuum treatment in step ii) is carried out over a period of 5 min to 6 h, preferably from 10 min to 4 h and particularly preferably from 10 min to 2 h.

[0065] In one embodiment of the process according to the invention, the vacuum treatment in step ii) is carried out by introducing inert gases and / or water vapor, preferably nitrogen, below the liquid level into the intermediate (D).

[0066] According to the invention, inert gases are understood to mean gases which are very unreactive under the prevailing reaction conditions, such as nitrogen and noble gases, preferably argon and nitrogen, particularly preferably nitrogen.

[0067] According to the invention, the term "below the liquid level" is to be understood as meaning that the fill level in the reactor with reaction mixture at the time in question, here during step ii), is geographically higher than the inlet opening(s) through which the inert gas is introduced into the reactor. To ensure an efficient stripping process, for example, even in the event of thrombus formation during stirring, it is recommended to position the inlet opening(s) for the inert gas at a suitable location in the bottom region of the reactor. Inert gases can be introduced, for example, via dip tubes or distributor rings.

[0068] In one embodiment of the process according to the invention, the inert gases, preferably nitrogen, and / or water vapor are introduced in amounts of 1 mL / (min kg (intermediate (D))) to 50 mL / (min kg (intermediate (D))), preferably from 3 mL / (min kg (intermediate (D))) to 30 mL / (min kg (intermediate (D))) below the liquid level of the intermediate (D).

[0069] In a preferred embodiment of the process according to the invention, the vacuum treatment in step ii) is carried out in the same reactor as steps i) and iii), optionally steps i), iii) and iv), so that no additional (time-consuming) transfer of the intermediate (D) after step i) or of the intermediate (E) before step iii) into separate reactors is necessary.

[0070] In a less preferred embodiment of the process according to the invention, the vacuum treatment in step ii) is carried out in a stripping column, preferably in a stripping column which contains packing or internals.

[0071] According to the invention, in step iii) the addition of the alkylene oxide (F) to the intermediate (E) optionally takes place in the presence of the basic catalyst (G) to form the alkaline polyoxyalkylene polyol (H), preferably the alkaline polyether polyol (H1).

[0072] In one embodiment of the process according to the invention, step iii) is carried out at a temperature of 70 °C to 170 °C, preferably from 100 °C to 150 °C. The temperature can be varied within the described limits during the alkylene oxide metering phase in step iii).

[0073] In one embodiment of the process according to the invention, step iii) is carried out at a pressure of 0.001 bara to 10 bara, preferably from 0.01 bara to 7 bara.

[0074] In steps i) and iii), the alkylene oxides (A) and (F) are continuously fed into the reactor in the conventional manner such that the safety pressure limits of the reactor system used are not exceeded. When metering ethylene oxide-containing alkylene oxide mixtures or pure ethylene oxide, particular care must be taken to ensure that a sufficient inert gas partial pressure is maintained in the reactor during the start-up and metering phases. This can be adjusted, for example, using noble gases or nitrogen. The alkylene oxides can be fed into the reactor in various ways: Dosing is possible into the gas phase or directly into the liquid phase, e.g., via a dip tube or a distributor ring located near the reactor bottom in a well-mixed zone.When dosing into the liquid phase, the dosing units should be designed to be self-draining, for example, by installing the dosing holes on the underside of the distributor ring. Backflow of reaction medium into the alkylene oxide-carrying lines and dosing units, or into the alkylene oxide storage tanks, can advantageously be prevented by appropriate equipment, such as the installation of check valves.

[0075] In a preferred embodiment of the process according to the invention, after the end of the addition of the alkylene oxide (F) in step iii) and before the preferred vacuum treatment in step iv), the alkaline polyoxyalkylene polyol (H), preferably the alkaline polyether polyol (H1), is treated in a second post-reaction phase at a temperature of 80°C to 170°C, preferably from 80°C to 150°C, and a pressure of 0.01 bara to 10 bara, preferably from 0.1 bara to 7 bara. The second post-reaction phase preferably takes place over a period of 20 minutes to 300 minutes, preferably from 50 minutes to 200 minutes.This is intended to reduce the amount of unreacted alkylene oxide (F) in the alkaline polyoxyalkylene polyol (H), preferably in the alkaline polyether polyol (Hl), which leads to better process efficiency of the preparation process according to the invention due to higher alkylene oxide conversions, but also to an increase in process reliability due to less unreacted (monomeric) alkylene oxide (F).

[0076] In one embodiment of the process according to the invention, after the addition of the alkylene oxide (F) in step iii) has ended and before the neutralization of the alkaline polyoxyalkylene polyol (H), preferably the alkaline polyether polyol (H1) in step v), the alkaline polyoxyalkylene polyol (H), preferably the alkaline polyether polyol (H1) is vacuum-treated at pressures of 1 mbara to 500 mbara, preferably of 2 mbara to 200 mbara, and particularly preferably of 2 mbara to 50 mbara in step iv).

[0077] In one embodiment of the process according to the invention, the vacuum treatment in step iv) is carried out at temperatures of 20 °C to 200 °C, preferably at 50 °C to 160 °C, particularly preferably at 100 °C to 150 °C.

[0078] In a preferred embodiment of the process according to the invention, step iv) is carried out at the same temperature as step iii).

[0079] In one embodiment of the process according to the invention, the vacuum treatment in step iv) is carried out over a period of 5 min to 6 h, preferably for 10 min to 4 h and particularly preferably for 10 min to 2 h.

[0080] In a less preferred embodiment of the process according to the invention, the vacuum treatment in step iv) is carried out by introducing inert gases and / or water vapor, preferably nitrogen, below the liquid level into the alkaline polyoxyalkylene polyol (H).

[0081] In a less preferred embodiment of the process according to the invention, the inert gases, preferably nitrogen, and / or water vapor are introduced in amounts of 1 mL / (min kg (alkaline polyoxyalkylene polyol (H)) to 50 mL / (min kg (alkaline polyoxyalkylene polyol (H)), preferably from 3 mL / ((alkaline polyoxyalkylene polyol (H)) to 30 mL / (min kg (alkaline polyoxyalkylene polyol (H)) below the liquid level of the alkaline polyoxyalkylene polyol (H)). Likewise in a less preferred embodiment of the process according to the invention, the vacuum treatment in step iv) is carried out in a stripping column, preferably in a stripping column which contains packing or internals.

[0082] According to the invention, in step v) water and optionally an acid (I) are added to the alkaline polyoxyalkylene polyol (H), preferably the alkaline polyether polyol (Hl) to form a mixture (J) comprising a first phase (Jl) containing the polyoxyalkylene polyol, preferably the polyether polyol, and a second, aqueous phase (J-2)).

[0083] In one embodiment of the process according to the invention, in step v), the mass ratio of added water to the alkaline polyoxyalkylene polyol (H) is from 0.07:1 to 0.7:1, preferably from 0.1:1 to 0.65:1. The amount of water added is composed of the directly added water and water which is introduced with the optionally added, optionally diluted acid (I).

[0084] In one embodiment of the process according to the invention, in step v) the alkaline polyoxyalkylene polyol (H), preferably the alkaline polyether polyol (H1) is neutralized by adding water and the acid (I) to form the mixture (J) comprising a first phase (J-1) containing the polyoxyalkylene polyol, preferably the polyether polyol, and a second aqueous phase (J-2) containing a neutralization salt.

[0085] For example, the alkaline polyoxyalkylene polyol (H), preferably the alkaline polyether polyol (Hl), can be neutralized with aqueous, dilute mineral acids such as sulfuric acid or phosphoric acid or by introducing carbon dioxide as acids (I).

[0086] In general, when using strong inorganic mineral acids, i.e. those with pKa values ​​of less than 2.5, degrees of neutralization between 90 and 120% are aimed for, with degrees of neutralization between 100 and 115% being preferred and degrees of neutralization between 102 and 112% being particularly preferred.

[0087] The degree of neutralization is defined as the percentage of added neutralization equivalents (effective acid equivalents) relative to the amount of alkaline catalyst to be neutralized. This is explained in more detail using the example of the strong inorganic mineral acids H2SO4 and H3PO4. Since the strength of the second dissociation stage of sulfuric acid is sufficient to protonate the alkali metal hydroxides formed by hydrolysis of the active alkoxide groups, 2 mol of alkoxide groups can be neutralized per mole of sulfuric acid used, thus providing 2 mol of neutralization equivalents per mole of sulfuric acid used. Thus, a degree of neutralization of 100% corresponds to a molar ratio of H2SO4 to alkali metal catalyst = 0.5. The weaker phosphoric acid, on the other hand, can only provide one neutralization equivalent, therefore it must be used in equimolar amounts to the amount of alkoxide groups to be neutralized.Thus, in the case of phosphoric acid, a degree of neutralization of 100% corresponds to the equimolar ratio of H3PO4 to alkali metal catalyst. In general, for the neutralization of alkali metal catalysts, e.g., KOH, with an acid S that can provide n moles of neutralization equivalents per mole, the degree of neutralization is: Degree of neutralization acid s = 100 xnx moles [acid S] / moles of catalyst (1). The degrees of neutralization when using sulfuric acid or phosphoric acid are therefore calculated using equations (2) and (3).

[0088] Degree of neutralization sulfuric acid = 200 x moles [H2SO4] / moles catalyst (2)

[0089] Degree of neutralization phosphoric acid = 100 x moles [H3PO4] / moles catalyst (3)

[0090] Carbon dioxide is a gaseous, weak inorganic acid; therefore, no degree of neutralization is usually specified for its use. The carbon dioxide is fed into the stream of alkaline polyoxyalkylene polyol (H), preferably into the stream of alkaline polyether polyol (HI), in stoichiometric ratios of CO2 / (mole catalyst) of approximately 1.5 to 2.5. Good dispersion of the carbon dioxide can then be ensured, for example, by a static mixing unit integrated into the mixture stream. Likewise, by such so-called "inline blending," water and / or aqueous solutions of inorganic acids can of course also be brought into intensive contact with the polyoxyalkylene polyol (H), preferably the alkaline polyether polyol (HI), to obtain the mixture (J).Water and / or aqueous solutions of inorganic acids such as phosphoric acid or sulfuric acid can, of course, also be mixed with the polyoxyalkylene polyol (H), preferably the alkaline polyether polyol (H1), in so-called neutralization vessels using conventional stirring conditions. According to the invention, in step vi), the second, aqueous phase (J-2), preferably containing the formed neutralization salt, is separated from the first phase (J1) containing the polyoxyalkylene polyol by gravity.

[0091] Such phase separation processes for separating the first phase (J1) from the second phase (J-2) can be accelerated by adding preferably non-polar solvents (K) such as toluene. Centrifuges have also proven helpful in phase separation processes. Exceptions to this are the polyether polyol production processes for specific polyether polyol types described in EP-A 2028211 and WO-A 2009106244. Phase separation processes can also be carried out on non-neutralized intermediates (H), for example by adding a sufficiently high amount of water to the non-neutralized intermediate (H), i.e., the intermediate (H) to which no acid (I) has been added, thoroughly emulsifying the mixture, and then separating the phases.

[0092] In one embodiment of the process according to the invention, in step v), water and a non-polar solvent (K) and optionally an acid (I) are added to the alkaline polyoxyalkylene polyol (H) to form a mixture (J) comprising a first phase (J1) containing the polyoxyalkylene polyol and the non-polar solvent (K) and a second, aqueous phase (J-2). This non-polar solvent (K) is preferably one or more compounds and is selected from the group consisting of n-pentane, isopentane, n-hexane, isohexane, cyclohexane, n-heptane, benzene, toluene and xylene, preferably from the group consisting of toluene, n-hexane, n-heptane and cyclohexane.

[0093] The volume ratio of the mixture (J) to the non-polar solvent (K) is preferably from 1.0 to 3.0, preferably from 1.0 to 2.5.

[0094] Separation by gravity utilizes the density difference between the (solvent-containing) polyoxyalkylene polyol phase and the base- or neutralization salt-containing phase. Such separation can be achieved purely passively, for example, by leaving the multiphase mixture to itself in a phase separation vessel for a sufficiently long period of time until the separation of the first and second phases has progressed sufficiently. Such passive phase separation can be supported by so-called coalescers. In this case, knitted fabrics or bundles of polymer, glass, ceramic, or mineral fibers through which the multiphase mixture is passed support the phase separation process. Supporting phase separation with centrifuges is more complex in terms of equipment but highly efficient. Such devices are well known to those skilled in the art and can also be operated continuously.They are able to accelerate the phase separation via the density difference by multiplying the acceleration due to gravity (up to approximately 10,000 g). Centrifuges that achieve an acceleration of 500 - 2,000 g are preferred, with those that can achieve accelerations of 1,000 - 2,000 g being particularly preferred.

[0095] In a preferred embodiment of the process according to the invention, after step vi), in step vii), the water and optionally, if used, the nonpolar solvent (L) are separated from the first phase (II) containing the polyoxyalkylene polyol. This can be done via vacuum-assisted distillation or with the aid of so-called stripping columns. In such columns, an inert gas or steam stream is passed against the product stream. Stripping columns with packed beds or internals are preferably used for this purpose. Such stripping processes can also be carried out continuously, for example by collecting the unstripped material, which still contains water and optionally solvent, in a buffer vessel and continuously feeding it from there to the stripping column.

[0096] In general, thorough mixing of the reactor contents should be ensured in all reaction phases, i.e. during steps i) to vii), by designing and using commercially available stirring elements. Single- or multi-stage stirrers or stirrer types acting over a large area across the fill level are particularly suitable here (see, for example, Handbook of Apparatus; Vulkan-Verlag Essen, 1st ed. (1990), pp. 188-208). Of particular technical relevance here is an average mixing power applied over the entire reactor contents, which is generally in the range of 0.2 to 5 W / l, with correspondingly higher local power inputs in the area of ​​the stirring elements themselves and, if necessary, at lower fill levels. In order to achieve optimal stirring, combinations of baffles (e.g. flat or tubular baffles) and cooling coils (or cooling candles) can be arranged in the reactor in accordance with the general state of the art; these can also extend across the vessel bottom.The stirring performance of the mixing unit can also be varied during the dosing phase depending on the fill level in order to ensure a particularly high energy input during critical reaction phases. For example, it can be advantageous to mix solid-containing dispersions, which may be present at the beginning of the reaction, for example, when using sucrose, particularly intensively. Furthermore, especially when using solid H-functional starter compounds, the choice of stirring unit should ensure sufficient dispersion of the solid in the reaction mixture. Bottom-running stirring stages and stirring elements particularly suitable for suspension are preferred. Furthermore, the stirrer geometry should contribute to reducing foaming of reaction products.Foaming of reaction mixtures can be observed, for example, after the end of the dosing phases in steps i) and iii) and the first and second post-reaction phases, if residual alkylene oxides are additionally removed under vacuum at absolute pressures in the range of 1 to 500 mbar in step ii) and optionally in step iv), preferably in steps ii) and iv). For such cases, agitator elements that achieve continuous mixing of the liquid surface have proven suitable. Depending on requirements, the agitator shaft has a bottom bearing and, if necessary, additional support bearings in the vessel. The agitator shaft can be driven from above or below (with a centric or eccentric arrangement of the shaft).Alternatively, it is also possible to achieve the necessary mixing exclusively by means of a pumped circulation circuit via a heat exchanger, or to operate this circuit in addition to the stirring unit as an additional mixing component, with the reactor contents being pumped as needed (typically 1 to 50 times per hour). The specific mixing power introduced by pumping, for example, via an external heat exchanger or when returning to the reactor via a nozzle or injector, also averages 0.2 to 5 W / L, whereby this is related to the liquid volume in the reactor and the pumped circulation circuit at the end of the reaction phase.

[0097] A wide variety of reactor types are suitable for carrying out the process according to the invention. Cylindrical vessels with a height-to-diameter ratio of 1:1 to 10:1 are preferred. Examples of suitable reactor bottoms include spherical, dished, flat, or conical bottoms.

[0098] After the end of the alkylene oxide feeds in steps i) and / or iii), the first or second post-reaction phases can follow, in which the decrease in the concentration of unreacted alkylene oxide can be quantified by monitoring the pressure. The end of such a post-reaction phase is reached when, at an approximately constant temperature, no further or only a very slow pressure drop can be detected in the reaction vessel. Such a criterion for the end of the post-reaction time can be individually specified. For example, a pressure drop rate of 20 mbar per hour is usually reached at pressures in the range of approximately 2 bar or higher. If such a pressure drop rate specified for the post-reaction time is reached or undercut, it is recommended to reduce the temperature to values ​​below 100 °C, preferably to values ​​below 80 °C, in order to suppress the formation of undesirable secondary components.If desired, the reaction mixture can be completely freed from small amounts of unreacted alkylene oxides after the end of the second post-reaction phase after step iii) under reduced pressure, for example at an absolute pressure of 1 to 500 mbar, or by stripping in step iv). Stripping removes volatile constituents, such as (residual) alkylene oxides, by introducing inert gases and / or steam into the liquid phase while simultaneously applying a vacuum (for example by passing an inert gas through at an absolute pressure of 5 to 500 mbar). The removal of volatile constituents, such as unreacted alkylene oxides, either under reduced pressure or by stripping, is generally carried out at temperatures of 20 to 200 °C, preferably at 50 to 160 °C, and preferably at reaction temperature with stirring.Such stripping processes can also be carried out in so-called stripping columns, in which an inert gas or steam stream is directed counter to the product stream. Stripping columns with packed beds or internals are preferably used for this purpose. Such stripping processes can also be carried out continuously, for example, by collecting the unstripped material in a buffer tank and continuously feeding it from there to the stripping column. After constant pressure has been reached in the post-reaction phase and, if necessary, after removing volatile components by vacuum and / or stripping, the product can be discharged from the reactor or fed to post-treatment steps, in particular workup steps.

[0099] It is recommended that the polyoxyalkylene polyol according to the invention, preferably the polyether polyol according to the invention, be prepared in the absence of oxygen. Handling and storage in the absence of oxygen is also recommended for the fully processed, salt-free, and stabilized polyoxyalkylene polyol according to the invention, preferably the polyether polyol according to the invention. Suitable inert gases for this purpose include, for example, noble gases, nitrogen, or carbon dioxide; noble gases or nitrogen are particularly suitable. By preventing the ingress of oxygen, product discoloration can be largely avoided. This applies particularly at elevated temperatures, which are generally used to facilitate handling of the finished products by reducing product viscosity.Furthermore, significantly fewer peroxide groups are formed under an inert gas atmosphere, which, by cleaving the polyether chains, contribute to the formation of other low-molecular-weight oxidative degradation products such as acetaldehyde, methanol, formic acid, formic acid esters, acetone, and formaldehyde. This minimizes quality degradation during storage of the finished products, reduces the content of volatile organic compounds, and prevents unpleasant odors and health risks.

[0100] One or more antioxidants (e.g., based on phenol derivatives and / or based on amines) can be added to the polyoxyalkylene polyol of the invention, preferably to the polyether polyol of the invention. If strong bases, such as alkali metal hydroxides, are used for the basic catalysis of the alkylene oxide addition to the starter compounds (B) used, it is recommended to add such antioxidants only after neutralization in step v) or after removal of the catalyst residues after step vi), since this prevents discoloration of the polyoxyalkylene polyols of the invention, preferably the polyether polyols of the invention, freed from catalyst residues.

[0101] The polyoxyalkylene polyol obtainable by the process according to the invention, preferably the polyether polyol obtainable by the process according to the invention, can be used as a starting component for the production of solid or foamed polyurethane materials and, less preferably, also for obtaining polyurethane elastomers. The polyurethane materials and elastomers can also contain isocyanurate, allophanate, and biuret structural units.

[0102] To produce these materials, 1. the polyoxyalkylene polyol according to the invention, preferably the polyether polyol according to the invention, is optionally mixed with further isocyanate-reactive components and

[0103] 2. organic polyisocyanates,

[0104] 3. optionally in the presence of one or more propellants,

[0105] 4. in the presence of one or more catalysts

[0106] 5. if necessary, reacted in the presence of other additives such as cell stabilizers.

[0107] A further polyoxyalkylene polyol, 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 admixed as a further isocyanate-reactive component to the polyoxyalkylene polyol according to the invention, preferably the polyether polyol according to the invention.

[0108] 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 Bronstcdt 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, as well as 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.-containing polyurethanes and / or melamine containing bonded amino groups.

[0109] 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 ratios of, for example, 20 to 35 / 40 to 60 / 20 to 36 wt.-Parts and especially adipic acid. Examples of di- and polyhydric alcohols are ethanediol, diethylene glycol, 1,2- or 1,3-propanediol, dipropylene glycol, methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,10-decanediol, 1,12-dodecanediol, glycerin, trimethylolpropane, and pentaerythritol. Preference is given to using 1,2-ethanediol, diethylene glycol, 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., s-caprolactone, or hydroxycarboxylic acids, e.g., hydroxycaproic acid and hydroxyacetic acid, can also be used.

[0110] To produce the polyester polyols, the organic, aromatic, or aliphatic polycarboxylic acids and / or polycarboxylic acid derivatives and polyhydric alcohols can be polycondensed catalyst-free or in the presence of esterification catalysts, advantageously in an atmosphere of inert gases such as nitrogen, helium, or argon, and also in the melt at temperatures of 150 to 300°C, preferably 180 to 230°C, optionally under reduced pressure, to the desired acid and OH numbers. The acid number is advantageously less than 10, preferably less than 2.5.

[0111] According to a preferred preparation process, the esterification mixture is polycondensed at the above-mentioned temperatures up to an acid number of 80 to 30, preferably 40 to 30, under atmospheric pressure and then under a pressure of less than 500 mbar, preferably 1 to 150 mbar. Suitable esterification catalysts include, for example, iron, cadmium, cobalt, lead, zinc, antimony, magnesium, titanium, and tin catalysts in the form of metals, metal oxides, or metal salts. However, the polycondensation of aromatic or aliphatic carboxylic acids with polyhydric alcohols can also be carried out in the liquid phase in the presence of diluents and / or entrainers, such as benzene, toluene, xylene, or chlorobenzene, for azeotropic distillation of the condensation water.

[0112] 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.

[0113] Suitable polycarbonate polyols are those of a known type, 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 α-co-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.

[0114] Low-molecular-weight, preferably tri- or tetrafunctional crosslinking agents or difunctional chain extenders can be added to the polyoxyalkylene polyol used according to the invention, preferably to the polyether polyol used according to the invention, to modify the mechanical properties, in particular the hardness, of the PUR materials. 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. Preferably used as chain extenders are alkanediols having 2 to 12 carbon atoms, e.g. ethanediol, 1,3-propanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol and in particular 1,4-butanediol and dialkylene glycols having 4 to 8 carbon atoms, e.g. diethylene glycol and dipropylene glycol.Also suitable are branched-chain and / or unsaturated alkanediols having usually not more than 12 carbon atoms, such as 1,2-propanediol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-butene-1,4-diol and 2-butyne-1,4-diol, diesters of terephthalic acid with glycols having 2 to 4 carbon atoms, such as terephthalic acid bis-ethylene glycol ester or terephthalic acid bis-1,4-butylene glycol ester and hydroxyalkylene ethers of hydroquinone or resorcinol, e.g. 1,4-di-(ß-hydroxyethyl)-hydroquinone or 1,3-(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'-diaminodicyclohexylmethane, N-alkyl-, N,N'-dialkyl-substituted and aromatic diamines, which can 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-sec.-butylbenzidine, methylenebis(4-amino-3-benzoic acid methyl ester), 2,4-chloro-4,4'-diamino-diphenylmethane, 2,4- and 2,6-toluenediamine can be used.

[0115] Mixtures of different chain extenders and crosslinking agents as well as mixtures of chain extenders and crosslinking agents can also be used.

[0116] Suitable organic polyisocyanates are cycloaliphatic, araliphatic, aromatic and heterocyclic polyisocyanates, as described, for example, by W. Siefken in Justus Liebigs Annalen der Chemie, 562, pages 75 to 136, for example those of the formula Q(NCO)n in which n = 2-4, preferably 2, and Q is an aliphatic hydrocarbon radical with 2-18, preferably 6-10 C atoms, a cycloaliphatic hydrocarbon radical with 4-15, preferably 5-10 C atoms, an aromatic hydrocarbon radical with 6-15, preferably 6-13 C atoms, or an araliphatic hydrocarbon radical with 8-15, preferably 8-13 C atoms. Suitable are, for example:Ethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), 1,12-dodecane diisocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,3- and -1,4-diisocyanate and any mixtures of these isomers, l-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane (DE-B 1 202 785, US-A 3 401 190), 2,4- and 2,6-hexahydrotoluene diisocyanate and any mixtures of these isomers, hexahydro-1,3- and -1,4-phenylene diisocyanate, perhydro-2,4'- and -4,4'-diphenylmethane diisocyanate, 1,3- and 1,4-phenylene diisocyanate (DE-A 196 27 907), 1,4-durene diisocyanate (DDI), 4,4'-stilbene diisocyanate (DE-A 196 28 145), 3,3'-dimethyl-4,4'-biphenylene diisocyanate (DIBDI) (DE-A 195 09 819), 2,4- and 2,6-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).

[0117] Further examples of suitable compounds according to the invention are: triphenylmethane-4,4',4"-triisocyanate, polyphenyl-polymethylene polyisocyanates as obtained by aniline-formaldehyde condensation and subsequent phosgenation and described, for example, in GB-A 874 430 and GB-A 848 671, m- and p-isocyanatophenylsulfonyl isocyanates according to US-A 3 454 606, perchlorinated aryl polyisocyanates as described in US-A 3 277 138, polyisocyanates containing carbodiimide groups as described in US-A 3 152 162 and in DE-A 25 04 400, 25 37 685 and 25 52 350, norbornane diisocyanates according to US-A 3 492 301, polyisocyanates containing allophanate groups as described in GB-A 994 890, BE-B 761 626 and NL-A 7 102 524, polyisocyanates containing isocyanurate groups, as described in US-A 3 001 9731, in DE-C 10 22 789, 12 22 067 and 1 027 394 as well as in DE-A 1 929 034 and 2 004 048, polyisocyanates containing urethane groups, as described e.g.in BE-B 752 261 or in US-A 3 394 164 and 3 644 457, polyisocyanates containing acylated urea groups according to DE-C 1 230 778, polyisocyanates containing biuret groups as described in US-A 3 124 605, 3 201 372 and 3 124 605 and in GB-B 889 050, polyisocyanates prepared by telomerization reactions as described in US-A 3 654 106, polyisocyanates containing ester groups as mentioned in GB-B 965 474 and 1 072 956, in US-A 3 567 763 and in DE-C 1 231 688, reaction products of the abovementioned isocyanates with Acetals according to DE-C 1 072 385 and polyisocyanates containing polymeric fatty acid esters according to US-A 3 455 883.

[0118] 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.

[0119] Preferably used are the technically readily available polyisocyanates, e.g. 2,4- and 2,6-toluene diisocyanate and any mixtures of these isomers ("TDI"), polyphenyl-polymethylene polyisocyanates, as produced by aniline-formaldehyde condensation and subsequent phosgenation ("crude MDI") and polyisocyanates containing carbodiimide groups, urethane groups, allophanate groups, isocyanurate groups, urea groups or biuret groups ("modified polyisocyanates"), in particular those modified polyisocyanates which differ from

[0120] 2,4- and / or 2,6-toluene diisocyanate or 4,4'- and / or 2,4'-diphenylmethane diisocyanate. Naphthylene 1,5-diisocyanate and mixtures of the above-mentioned polyisocyanates are also suitable.

[0121] It is also possible to use prepolymers containing isocyanate groups, which are obtainable by reacting a part or the total amount of the polyetherester polyols to be used according to the invention and / or a part or the total amount of the isocyanate-reactive components described above, which may be added to the polyetherester polyols 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

[0122] 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 polyoxyalkylene polyol 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. The prepolymers containing isocyanate groups can be prepared in the presence of catalysts. However, it is also possible to prepare the prepolymers containing isocyanate groups in the absence of catalysts and to add them to the reaction mixture for producing the PUR materials.

[0123] Water can be used as an optional blowing agent. This 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 1, 4, and 5.

[0124] 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. Examples of organic blowing agents that can be used include acetone, ethyl acetate, methyl acetate, halogen-substituted alkanes such as methylene chloride, chloroform, ethylidene chloride, vinylidene chloride, monofluorotrichloromethane, chlorodifluoromethane, dichlorodifluoromethane, HFCs such as R 134a, R 245fa, and R 365mfc, partially halogenated olefins (so-called HFOs or HCFOs) such as trans-l,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 blowing agents can also be used as mixtures.Suitable inorganic blowing agents include air, CO2, or N2O. A blowing 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. Further examples of blowing agents, details on the use of blowing agents and criteria for the selection of blowing agents are described in R. Vieweg, A. Höchtlen (eds.): “Kunststoff-Handbuch”, Volume VII, Carl-Hanser-Verlag, Munich 1966, pp. 108f, 453ff and 507-510 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.

[0125] 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 given by solid 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 1 and 2. The gas loading with e.g. B. Air, carbon dioxide, nitrogen and / or helium can be introduced either via the formulation components 1, 4 and 5 or via the polyisocyanates 2 or via 1, 4, 5 on the one hand and 2 on the other hand.

[0126] As component 4, amine catalysts familiar to the person skilled in the art can be used, e.g. tertiary amines such as triethylamine, tributylamine, N-methylmorpholine, N-ethylmorpholine, N,N,N',N'-tetramethylethylenediamine, pentamethyldiethylenetriamine and higher homologues (DEOS 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-dimethylcyclohexylamine, N,N-diethylbenzylamine, bis-(N,N-diethylaminoethyl)adipate, N,N,N',N'-tetramethyl-l,3-butanediamine, N,N-Dimethyl-ß-phenyl-ethyl-amine, bis-(dimethylaminopropyl)-urea, 1,2-dimethylimidazole, 2-methylimidazole, monocyclic and bicyclic amidines (DE-A 17 20 633), bis-(dialkylamino)-alkyl ethers (US-A 3 330 782, DE-B 10 30 558, DE-A 18 04 361 and 26 18 280) and tertiary amines containing amide groups (preferably formamide groups) according to DE-A 25 23 633 and 27 32 292).Also suitable as catalysts are known Mannich bases made from secondary amines, such as dimethylamine, and aldehydes, preferably formaldehyde, or ketones such as acetone, methyl ethyl ketone or cyclohexanone and phenols, such as phenol or alkyl-substituted phenols. Tertiary amines containing hydrogen atoms active toward isocyanate groups that can be used as catalysts include triethanolamine, triisopropanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N,N-dimethylethanolamine, their reaction products with alkylene oxides such as propylene oxide and / or ethylene oxide, and secondary tertiary amines according to DE-A 27 32 292. Silaamines with carbon-silicon bonds, as described in US-A 3,620,984, can also be used as catalysts, e.g., 2,2,4-trimethyl-2-silamorpholine and 1,3-diethylaminomethyltetramethyldisiloxane. Nitrogen-containing bases such as tetraalkylammonium hydroxides and hexahydrotriazines are also suitable.The reaction between NCO groups and Zerewitinoff-active hydrogen atoms is also strongly accelerated by lactams and azalactams, whereby an association is initially formed between the lactam and the compound with acidic hydrogen.

[0127] If amines are used as catalysts to catalyze the polyurethane reaction, it should of course be noted that polyoxyalkylene polyols according to the invention prepared under amine catalysis and / or an optional additional polyoxyalkylene polyol used for the polyurethane reaction may already contain catalytically active amines. However, by conducting suitable test series, it is readily possible for the skilled person to determine the amounts of amine catalysts that may still need to be added.

[0128] Furthermore, conventional organic metal compounds can be used as catalysts for this purpose, preferably organic tin compounds such as tin(II) salts of organic carboxylic acids, e.g., tin(II) acetate, tin(II) octoate, tin(II) ethylhexoate, and tin(II) taurate, and, 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.

[0129] Catalysts that specifically catalyze the trimerization of NCO groups are used to produce polyurethane materials with high proportions of so-called poly(isocyanurate) structures ("PIR foams"). Typically, formulations with significant excesses of NCO groups over OH groups are used to produce such materials. PIR foams are typically produced with isocyanate to hydroxyl groups (KPIs) between 180 and 450, where the KPI is defined as the ratio of isocyanate groups to hydroxyl groups multiplied by a factor of 100. Catalysts that contribute to the formation of isocyanurate structures include metal salts such as potassium or sodium acetate, sodium octoate, and amino compounds such as 1,3,5-tris(3-dimethylaminopropyl)hexahydrotriazine.

[0130] The catalysts or catalyst combinations are generally used in an amount of between about 0.001 and 10 wt.%, in particular 0.01 to 4 wt.%, based on the total amount of compounds having at least two hydrogen atoms reactive towards isocyanates.

[0131] In the absence of moisture and physically or chemically acting blowing agents, compact PUR materials can also be produced.

[0132] During the production of compact or foamed PUR materials, additives 5 may be used if necessary. Examples include surface-active additives such as emulsifiers, foam stabilizers, cell regulators, flame retardants, nucleating agents, antioxidants, stabilizers, lubricants and mold-release agents, dyes, dispersing aids, and pigments. 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 or ammonium salts of sulfonic acids such as dodecylbenzenesulfonic acid or dinaphthylmethanedisulfonic acid, or of fatty acids such as ricinoleic acid, or of polymeric fatty acids. Polyether siloxanes are particularly suitable as foam stabilizers.These compounds are generally constructed by combining copolymers of ethylene oxide and propylene oxide with a polydimethylsiloxane residue. Such foam stabilizers can be reactive toward isocyanates or, due to etherification of the terminal OH groups, unreactive toward isocyanates. They are described, for example, in US Pat. Nos. 2,834,748, 2,917,480, and 3,629,308. General structures of such foam stabilizers are given in G. Oertel (ed.): "Kunststoff-Handbuch," Volume VII, Carl Hanser Verlag, Munich, Vienna 1993, pp. 113-115. Of particular interest are polysiloxane-polyoxyalkylene copolymers according to DE-A 25 58 523, which are often branched via allophanate groups. Other organopolysiloxanes, oxyethylated alkylphenols, oxyethylated fatty alcohols and paraffin oils, and cell regulators such as paraffins, fatty alcohols and dimethylpolysiloxanes are also suitable.Oligomeric polyacrylates with polyoxyalkylene and fluoroalkane residues as side groups are also suitable for improving the emulsifying effect, the dispersion of the filler, the cell structure, and / or for their stabilization. The surface-active substances are typically used in amounts of 0.01 to 5 parts by weight, based on 100 parts by weight of component 1. 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 additives and foam stabilizers, as well as cell regulators, reaction retarders, stabilizers, flame-retardant substances, plasticizers, dyes and fillers, as well as fluorostatic 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.

[0133] To produce PUR or PIR materials, the ratio of isocyanate groups in polyisocyanates 2 to the isocyanate-reactive hydrogens in components 1, 3, 4, and 5 can be varied widely. Typical ratios are 0.7:1 to 5:1.

[0134] The PUR or PIR materials can be produced by 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 polyoxyalkylene polyol, preferably the polyether polyol, which can be produced particularly advantageously by the process according to the invention, can be processed with a poly-1-isocyanate and optionally used physical blowing agents 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 automobile seats, upholstered furniture, and mattresses. The polyoxyalkylene polyol according to the invention, preferably the polyether polyol, can be fed to the mechanical mixing unit either as an individual component or as part of a pre-prepared formulation.The low viscosity of the polyoxyalkylene polyols according to the invention, preferably the polyether polyols according to the invention, proves to be particularly advantageous for the mechanical processing.

[0135] In a first embodiment, the invention relates to a process for preparing a polyoxyalkylene polyol, preferably a polyether polyol, comprising the following steps: i) addition of an alkylene oxide (A) to an H-functional starter substance (B) in the presence of a basic catalyst (C) to form an intermediate (D), ii) vacuum treatment of the intermediate (D) at pressures of 1 mbar to 500 mbar, preferably from 2 mbar to 200 mbar, and particularly preferably from 2 mbar to 50 mbar to form an intermediate (E), iii) addition of an alkylene oxide (F) to the intermediate! (E) optionally in the presence of a basic catalyst (G) to form an alkaline polyoxyalkylene polyol (H), preferably an alkaline polyether polyol (Hl), iv) Optionally vacuum treatment of the alkaline polyoxyalkylene polyol (H), preferably the alkaline polyether polyol (Hl) at pressures of 1 mbara to 500 mbara, preferably of 2 mbara to 200 mbara,and particularly preferably from 2 mbara to 50 mbara, v) adding water and optionally an acid (I) to the alkaline polyoxyalkylene polyol (H), preferably to the alkaline polyether polyol (H1) to form a mixture (J) comprising a first phase (J1) containing the polyoxyalkylene polyol and a second, aqueous phase (J-2), vi) separating the second, aqueous phase (J-2) from the first phase (J1) containing the polyoxyalkylene polyol by gravity, wherein the addition of the alkylene oxide (A) in step i) is terminated before the vacuum treatment in step ii) and the addition of the alkylene oxide (F) begins only after the vacuum treatment in step ii) has been completed.

[0136] In a second embodiment, the invention relates to a process according to the first embodiment, wherein the polyoxyalkylene polyol, preferably the polyether polyol, has a hydroxyl number of 25 mg KOH / g to 100 mg KOH / g, preferably 28 mg KOH / g to 60 mg KOH / g, wherein the hydroxyl number was determined by means of the method DIN 53240-2 (2007-11) disclosed in the experimental part.

[0137] In a third embodiment, the invention relates to a process according to the first or second embodiment, wherein the polyoxyalkylene polyol, preferably the polyether polyol, has a molar proportion of primary hydroxyl groups of > 50 mol% to < 100 mol%, wherein the molar proportion of primary hydroxyl groups is determined by means of NMR spectroscopy according to the method described in WO 2021 / 198054 A1.

[0138] In a fourth embodiment, the invention relates to a process according to any one of the first to third embodiments, wherein the alkylene oxide (A) is propylene oxide or a mixture of ethylene oxide and propylene oxide with up to 30 mass % ethylene oxide based on the total mass of the mixture of ethylene oxide and propylene oxide of the alkylene oxide (A).

[0139] In a fifth embodiment, the invention relates to a process according to any one of the first to fourth embodiments, wherein the H-functional starter substance (B) is a polyol, preferably a polyfunctional alcohol, a polyfunctional amine, a polyether polyol, and a polyether ester polyol, and particularly preferably a polyether polyol and / or a polyfunctional alcohol.

[0140] In a sixth embodiment, the invention relates to a process according to any one of the first to fifth embodiments, wherein the H-functional starter substances (B) 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 part.

[0141] In a seventh embodiment, the invention relates to a process according to any one of the first to sixth embodiments, wherein the basic catalyst (C) is an alkali metal hydroxide, preferably sodium hydroxide and / or potassium hydroxide.

[0142] In an eighth embodiment, the invention relates to a process according to the seventh embodiment, wherein the basic catalyst (C) is used in an amount of 0.004 to 0.8 wt.%, preferably 0.004 to 0.5 wt.%, based on the amount of final product.

[0143] In a ninth embodiment, the invention relates to a process according to any one of the first to eighth embodiments, wherein the alkylene oxide (F) is ethylene oxide or a mixture of ethylene oxide and propylene oxide with at least 70 mass% ethylene oxide based on the total mass of the mixture of ethylene oxide and propylene oxide of the alkylene oxide (F).

[0144] In a tenth embodiment, the invention relates to a process according to any one of the first to ninth embodiments, wherein no further basic catalyst (G) is added in step iii).

[0145] In an eleventh embodiment, the invention relates to a process according to any one of the first to tenth embodiments, wherein the basic catalyst (C) and the basic catalyst (G) are identical.

[0146] In a twelfth embodiment, the invention relates to a process according to any one of the first to eleventh embodiments, wherein the catalyst (C) and catalyst (G) are basic catalysts (C-1) and (Gl), preferably alkali metal hydroxides.

[0147] In a thirteenth embodiment, the invention relates to a process according to any one of the first to twelfth embodiments, wherein the acid (I) is a mineral acid, a hydroxycarboxylic acid, a cyclic dicarboxylic anhydride, carbon dioxide, and / or an incompletely alkoxylated oxoacid of phosphorus, preferably a mineral acid. In a fourteenth embodiment, the invention relates to a process according to any one of the first to thirteenth embodiments, wherein the acid (I) is phosphoric acid and / or sulfuric acid, preferably dilute, aqueous phosphoric acid and / or dilute, aqueous sulfuric acid.

[0148] In a fifteenth embodiment, the invention relates to a process according to any one of the first to fourteenth embodiments, wherein the acid (I) is an organic acid, preferably adipic acid, formic acids and / or acetic acid.

[0149] In a sixteenth embodiment, the invention relates to a process according to any one of the first to fifteenth embodiments, wherein step i) is carried out at a temperature of 70 °C to 130 °C, preferably of 80 °C to 115 °C.

[0150] In a seventeenth embodiment, the invention relates to a process according to any one of the first to sixteenth embodiments, wherein step i) is carried out at a pressure of 0.001 bara to 10 bara, preferably of 0.01 bara to 7 bara.

[0151] In an eighteenth embodiment, the invention relates to a process according to one of the first to seventeenth embodiments, wherein step i) comprises the following substeps: i-1) addition of a first partial amount (A1) of the alkylene oxide (A) to the polyether polyol and / or the polyfunctional alcohol as H-functional starter substance (B) in the presence of the alkali metal hydride, the alkali metal carboxylate and / or the alkali metal hydroxide, preferably the alkali metal hydroxide as basic catalyst (C) to form an alkali metal alkoxylate, i-2) reaction of the alkali metal alkoxylate with a second partial amount (A-2) of the alkylene oxide (A) to form the intermediate (D).

[0152] In a nineteenth embodiment, the invention relates to a process according to the eighteenth embodiment, wherein the molar fraction n(Al) of the first portion of the alkylene oxide (Al) added in step i-1) is from 6 mol% to 20 mol%, preferably from 8 mol% to 18 mol% and particularly preferably from 10 mol% to 16 mol%, based on the sum of the molar amounts of the first portion n(Al) and the second portion n(A-2).

[0153] In a twentieth embodiment, the invention relates to a process according to the eighteenth or nineteenth embodiment, wherein further basic catalyst (Cl) such as alkali metal hydride, alkali metal carboxylate and / or alkali metal hydroxide, preferably alkali metal hydroxide, is added to the alkali metal alkoxylate obtained in step i-1) before the further reaction in step i-2) and optionally dehydrated

[0154] In a twenty-first embodiment, the invention relates to a process according to the twentieth embodiment, wherein the dewatering of the alkali metal alkoxylate obtained in step i-1) and admixed with further basic catalyst Cl is carried out at 80 °C to 150 °C and 500 mbara to 1 mbara for 10 min to 3 h.

[0155] In a twenty-second embodiment, the invention relates to a process according to any one of the first to twenty-first embodiments, wherein no water and / or acid addition takes place between steps i) and ii). In a twenty-third embodiment, the invention relates to a process according to any one of the first to twenty-second embodiments, wherein after the end of the addition of the alkylene oxide (A) in step i) and before the vacuum treatment in step ii), the intermediate (D) is treated in a first post-reaction phase at a temperature of 80°C to 150°C, preferably 80°C to 115°C, and a pressure of 0.01 bara to 10 bara, preferably 0.1 bara to 7 bara.

[0156] In a twenty-fourth embodiment, the invention relates to a process according to the twenty-third embodiment, wherein the first post-reaction phase takes place over a period of 20 min to 300 min, preferably from 50 min to 200 min.

[0157] In a twenty-fifth embodiment, the invention relates to a process according to the twenty-third or twenty-fourth embodiment, wherein the first post-reaction phase takes place at a higher temperature than that at which the reaction in step i) took place.

[0158] In a twenty-sixth embodiment, the invention relates to a process according to any one of the first to twenty-fifth embodiments, wherein the vacuum treatment in step ii) is carried out at temperatures of 20 to 200 °C, preferably at 50 to 160 °C, particularly preferably at 100 °C to 150 °C.

[0159] In a twenty-seventh embodiment, the invention relates to a process according to any one of the first to twenty-sixth embodiments, wherein the vacuum treatment in step ii) is carried out over a period of 5 min to 6 h, preferably from 10 min to 4 h and particularly preferably from 10 min to 2 h.

[0160] In a twenty-eighth embodiment, the invention relates to a process according to any one of the first to twenty-seventh embodiments, wherein the vacuum treatment in step ii) is carried out by introducing inert gases and / or water vapor, preferably nitrogen, below the liquid level into the intermediate (D).

[0161] In a twenty-ninth embodiment, the invention relates to a process according to one of the first to twenty-eighth embodiments, wherein the introduction of the inert gases and / or water vapor, preferably nitrogen, takes place in amounts of 1 mL / (min kg (intermediate (D))) to 50 mL / (min kg (intermediate (D))), preferably of 3 mL / (min kg (intermediate (D))) to 30 mL / (min kg (intermediate (D))) below the liquid level of the intermediate (D).

[0162] In a thirtieth embodiment, the invention relates to a process according to any one of the first to twenty-ninth embodiments, wherein the vacuum treatment in step ii) is carried out in the same reactor as steps i) and iii), optionally steps i), iii), and iv). In a thirty-first embodiment, the invention relates to a process according to any one of the first to twenty-ninth embodiments, wherein the vacuum treatment in step ii) is carried out in a stripping column, preferably in a stripping column containing packing or internals. In a thirty-second embodiment, the invention relates to a process according to any one of the first to thirty-first embodiments, wherein step iii) is carried out at a temperature of 70°C to 170°C, preferably of 100°C to 150°C.

[0163] In a thirty-third embodiment, the invention relates to a process according to any one of the first to thirty-second embodiments, wherein step iii) is carried out at a pressure of 0.001 bara to 10 bara, preferably from 0.01 bara to 7 bara.

[0164] In a thirty-fourth embodiment, the invention relates to a process according to any one of the first to thirty-third embodiments, wherein after the addition of the alkylene oxide (F) in step iii) has ended, the alkaline polyoxyalkylene polyol (EI), preferably the alkaline polyether polyol (HI) is treated at a temperature of 80 °C to 170 °C, preferably from 80 °C to 150 °C and a pressure of 0.01 bara to 10 bara, preferably from 0.1 bara to 7 bara in a second post-reaction phase.

[0165] In a thirty-fifth embodiment, the invention relates to a process according to the thirty-fourth embodiment, wherein the second post-reaction phase takes place over a period of 20 min to 300 min, preferably 50 min to 200 min.

[0166] In a thirty-sixth embodiment, the invention relates to a process according to any one of the first to thirty-fifth embodiments, wherein after the end of the addition of the alkylene oxide (F) in step iii) and before the addition of water and the optional neutralization of the alkaline polyoxyalkylene polyol (H), preferably the alkaline polyether polyol (Hl) in step v), the alkaline polyoxyalkylene polyol (H), preferably the alkaline polyether polyol (Hl) is vacuum-treated at pressures of 1 mbara to 500 mbara, preferably of 2 mbara to 200 mbara, and particularly preferably of 2 mbara to 50 mbara in step iv).

[0167] In a thirty-seventh embodiment, the invention relates to a process according to the thirty-sixth embodiment, wherein the vacuum treatment in step iv) is carried out at temperatures of 20 °C to 200 °C, preferably at 50 °C to 160 °C, particularly preferably at 100 °C to 150 °C.

[0168] In a thirty-eighth embodiment, the invention relates to a process according to any one of the first to thirty-seventh embodiments, wherein step iv) is carried out at the same temperature as step iii).

[0169] In a thirty-ninth embodiment, the invention relates to a process according to one of the first to thirty-eighth embodiments, wherein the vacuum treatment in step iv) is carried out over a period of 5 min to 6 h, preferably for 10 min to 4 h and particularly preferably for 10 min to 2 h.

[0170] In a fortieth embodiment, the invention relates to a process according to any one of the first to thirty-ninth embodiments, wherein the vacuum treatment in step iv) is carried out by introducing inert gases and / or water vapor, preferably nitrogen, below the liquid level into the alkaline polyoxyalkylene polyol (H). In a forty-first embodiment, the invention relates to a process according to the first to fortieth embodiments, wherein the introduction of the inert gases, preferably nitrogen, and / or water vapor is carried out in amounts of 1 mL / (min kg (alkaline polyoxyalkylene polyol (H)) to 50 mL / (min kg (alkaline polyoxyalkylene polyol (H)), preferably from 3 mL / ((alkaline polyoxyalkylene polyol (H)) to 30 mL / (min kg (alkaline polyoxyalkylene polyol (H)) below the liquid level of the alkaline polyoxyalkylene polyol (H)).

[0171] In a forty-second embodiment, the invention relates to a process according to any one of the first to forty-first embodiments, wherein in step v) the alkaline polyoxyalkylene polyol (EI), preferably the alkaline polyether polyol (HI) is neutralized by adding water and the acid (I) to form the mixture (J) comprising the first phase (JI) containing the polyoxyalkylene polyol and a second aqueous phase (J-2) containing a neutralization salt.

[0172] In a forty-third embodiment, the invention relates to a process according to the forty-second embodiment, wherein the alkaline polyoxyalkylene polyol (H), preferably the alkaline polyether polyol (Hl) is neutralized with aqueous, dilute mineral acids such as sulfuric acid or phosphoric acid or by introducing carbon dioxide as acids (I). _, li _,In a forty-fourth embodiment, the invention relates to a process according to any one of the first to forty-third embodiments, wherein in step v) water and a non-polar solvent (K) and optionally an acid (I) are added to the alkaline polyoxyalkylene polyol (H) to form a mixture (J) comprising a first phase (J1) containing the polyoxyalkylene polyol and the non-polar solvent (K) and a second, aqueous phase (J-2).

[0173] In a forty-fifth embodiment, the invention relates to a process according to the forty-fourth embodiment, wherein non-polar solvent (K) is one or more compounds and is selected from the group consisting of n-pentane, iso-pentane, n-hexane, iso-hexane, cyclohexane, n-heptane, benzene, toluene and xylene, preferably from the group consisting of toluene, n-hexane, n-heptane and cyclohexane.

[0174] In a forty-sixth embodiment, the invention relates to a process according to the forty-fourth or forty-fifth embodiment, wherein the volume ratio of the mixture (J) to the non-polar solvent (K) is preferably from 1.0 to 3.0, preferably from 1.0 to 2.5.

[0175] In a forty-seventh embodiment, the invention relates to a process according to any one of the first to forty-sixth embodiments, wherein in step v) the mass ratio of added water to the alkaline polyoxyalkylene polyol (H) is from 0.07: 1 to 0.7: 1, preferably from 0.1: 1 to 0.65: 1.

[0176] In a forty-eighth embodiment, the invention relates to a process according to any one of the first to forty-seventh embodiments, wherein the separation in step vi) is carried out via a coalescer. In a forty-ninth embodiment, the invention relates to a process according to any one of the first to forty-seventh embodiments, wherein the separation in step vi) is carried out via a centrifuge.

[0177] In a fiftieth embodiment, the invention relates to a process according to any one of the first to forty-ninth embodiments, wherein after step vi), in step vii), the water is separated from the first phase (Jl) containing the polyoxyalkylene polyol.

[0178] In a fifty-first embodiment, the invention relates to a process according to the fiftieth embodiment, wherein the separation is carried out by means of vacuum-assisted distillation or using a stripping column. In a fifty-second embodiment, the invention relates to a process according to the fifty-first embodiment, wherein the stripping column contains packing or internals.

[0179] In a fifty-third embodiment, the invention relates to a mixture (J) comprising a first phase (J1) comprising the polyoxyalkylene polyol and a second, aqueous phase (J-2), preferably comprising a neutralization salt obtainable by the process according to any of the first to fifty-second embodiments.

[0180] Examples

[0181] Methods:

[0182] The OH numbers were determined according to DIN 53240-2 (2007-11). The alkali number of the alkali metal alkoxylate was determined according to ASTM D 4662-87. The water content was determined using the Karl Fischer method according to ASTM D 4672-91.

[0183] Raw materials used

[0184] IRGANOX 1076: Octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate

[0185] Preparation of the alkali metal alkoxylate of a glycerol-initiated polyoxyalkylene polyol in step i-1):

[0186] 878.8 g of glycerol and 39.7 g of an aqueous KOH solution (containing 45 wt.% KOH) were combined at 60 °C in a 10 l autoclave. The mixture was dehydrated at 115 °C under vacuum with stirring (450 rpm) until a pressure of less than 10 mbar was reached. At 115 °C, 5121.2 g of propylene oxide were then metered in as the first portion (Al) of the alkylene oxide (A) in such a way that a total pressure of 3 bar was not exceeded. After a post-reaction time of 150 min at 115 °C, the reaction mixture was baked for 30 min at 115 °C under vacuum. The reactor contents were cooled to 80 °C, and 583.4 g of an aqueous KOH solution (containing 45 wt.% KOH) were added as an additional basic catalyst (Cl). Dehydration was carried out under vacuum at 110 °C until a pressure of less than 10 mbar was reached. The resulting alkali metal alkoxylate of a glycerol-initiated polyoxyalkylene polyol had an alkali number of 45.6 mg KOH / g and an OH number of 253.2 mg KOH / g.

[0187] Example 1 (comparison):

[0188] 90.5 g of the alkali metal alkoxylate of the glycerol-initiated polyoxyalkylene polyol from step i-1) were placed in a 2 l laboratory autoclave under a nitrogen atmosphere, and the autoclave was sealed. Oxygen was removed at room temperature by pressurizing the autoclave with nitrogen five times to an absolute pressure of 3 bar and then evacuating to 15 mbar. The contents of the autoclave were heated to 115 °C with stirring (crossbar stirrer, 800 rpm). At 115 °C, in step i-2), 982.4 g of propylene oxide (alkylene oxide (A-2)) were metered into the headspace of the reactor over a period of 3.93 h. After an initial post-reaction phase at 115 °C lasting 3.26 h, during which the reactor pressure dropped from 4.3 to 1.5 bar, intermediate (D) was obtained. The temperature was increased to 130 °C and 130.7 g of ethylene oxide (alkylene oxide (F)) were metered into the headspace of the reactor in step iii) over a period of 0.53 h.After a second post-reaction phase lasting 1.02 h at 130 °C, during which the reactor pressure dropped from 2.5 bar to 1.8 bar, the contents of the autoclave were baked out at 130 °C over a period of 33 min under vacuum (17 mbar), whereby the alkaline polyether polyol (H- 1) was obtained. After cooling to 80 °C, 120 ml of distilled water, 30.59 g of a 12.14 wt. % solution of sulfuric acid in water and 0.646 g of IRGANOX 1076 in step iv) were added and the resulting emulsion was stirred for 30 min. 793.6 g of this emulsion were transferred to a glass reactor with double-jacketed heating and stirring unit and 79 ml of distilled water were added. The ratio of water to alkaline polyoxyalkylene polyol was 0.23:1. Stirring was continued at 80 °C for a further 30 min. The stirrer was turned off, and the reactor contents were allowed to stand at 80 °C for 24 h.After 24 hours, 101.3 g of a lower (aqueous) phase and 758.8 g of an upper (predominantly polyether-containing) phase were isolated, corresponding to a weight ratio of the aqueous phase to the polyether polyol phase of 1 to 7.49. The water content in the upper polyether polyol phase was 5.5 wt%.

[0189] Example 2 (inventive):

[0190] 90.0 g of the alkali metal alkoxylate of the glycerol-initiated polyoxyalkylene polyol from step i-1) were placed in a 2 l laboratory autoclave under a nitrogen atmosphere, and the autoclave was sealed. Oxygen was removed at room temperature by pressurizing the autoclave with nitrogen five times to an absolute pressure of 3 bar and then evacuating to 70 mbar. The contents of the autoclave were heated to 115 °C with stirring (crossbar stirrer, 800 rpm). At 115 °C, in step i-2), 982.4 g of propylene oxide (alkylene oxide (A-2)) were metered into the headspace of the reactor over a period of 3.95 h. After an initial post-reaction phase at 115 °C lasting 4.0 h, during which the reactor pressure dropped from 4.0 bar to 1.4 bar, intermediate (D) was obtained. In step ii), the reactor contents were stripped at 115 °C over a period of 4 h by introducing 50 ml of nitrogen / min while simultaneously applying a vacuum.A pressure of 140 mbar was established, yielding intermediate (E). The temperature was then increased to 130 °C, the reactor pressure was adjusted to 2.7 bar using nitrogen, and in step iii), 130.6 g of ethylene oxide (alkylene oxide (F)) were metered into the headspace of the reactor over a period of 0.53 h. After a second post-reaction phase lasting 1.0 h at 130 °C, during which the reactor pressure dropped from 3.7 bar to 3.1 bar, the contents of the autoclave were baked at 130 °C for 33 min under vacuum (17 mbar) in step iv), yielding the alkaline polyoxyalkylene polyol (H1). After cooling to 80 °C, 120 ml of distilled water, 30.39 g of a 12.14 wt% solution of sulfuric acid in water and 0.639 g of IRGANOX 1076 in step v) were added and the resulting emulsion was stirred for 30 min.763.0 g of this emulsion was transferred to a glass reactor equipped with double-jacketed heating and a stirrer, and 76 ml of distilled water was added. The ratio of water to alkaline polyoxyalkylene polyol was 0.23:1. Stirring was continued at 80 °C for a further 30 minutes. The stirrer was turned off, and the reactor contents were allowed to stand at 80 °C for 24 hours. After 24 hours, 108.0 g of a lower (aqueous) phase and 725.0 g of an upper (predominantly polyether-containing) phase were isolated, corresponding to a weight ratio of the aqueous phase to the polyether polyol phase of 1:6.71. The water content in the upper polyether polyol phase was 5.1 wt.%.

[0191] Example 3 (comparison):

[0192] 449.9 g of the alkali metal alkoxylate of the glycerol-initiated polyoxyalkylene polyol from step i-1) were placed in a 10 l laboratory autoclave under a nitrogen atmosphere, and the autoclave was sealed. Oxygen was removed at room temperature by pressurizing the autoclave five times with nitrogen to an absolute pressure of 3 bar and then evacuating to 15 mbar. The contents of the autoclave were heated to 115 °C with stirring (mesh stirrer, 450 rpm). At 115 °C, in step i-2), 4911.8 g of propylene oxide (alkylene oxide (A-2)) were metered into the headspace of the reactor over a period of 4.75 h. After an initial post-reaction phase at 115 °C lasting 0.5 h, during which the reactor pressure dropped from 4.6 bar to 2.8 bar, intermediate (D) was obtained. The temperature was maintained at 115 °C in step iii) and 653.6 g of ethylene oxide (alkylene oxide (F)) were metered into the headspace of the reactor over a period of 0.53 h.After a second post-reaction phase at 115 °C lasting 1.0 h, during which the reactor pressure dropped from 3.2 bar to 1.9 bar, the contents of the autoclave were heated at 130 °C for 30 min under vacuum (17 mbar), yielding the alkaline polyoxyalkylene polyol (H1). After cooling to 80 °C, 600 ml of distilled water, 147.90 g of a 12.47 wt. % solution of sulfuric acid in water, and 3.019 g of IRGANOX 1076 were added in step iv), and the resulting emulsion was stirred for 30 min. 758.9 g of this emulsion were transferred to a glass reactor with jacket heating and a stirrer, and 75 ml of distilled water were added. The ratio of water to alkaline polyoxyalkylene polyol was 0.23:1. Stirring was continued at 80 °C for a further 30 min. The stirrer was turned off, and the reactor contents were allowed to stand at 80 °C for 24 h. After 24 h, 733.0 g of an upper (predominantly polyether-containing) phase could be isolated.The water content in this upper polyether polyol phase was 7.6 wt%.

[0193] Example 4 (comparison):

[0194] 90.2 g of the alkali metal alkoxylate of the glycerol-initiated polyoxyalkylene polyol from step i-1) were placed in a 2 l laboratory autoclave under a nitrogen atmosphere, and the autoclave was sealed. Oxygen was removed at room temperature by pressurizing the autoclave with nitrogen five times to an absolute pressure of 3 bar and then evacuating to 20 mbar. The contents of the autoclave were heated to 115 °C with stirring (crossbar stirrer, 800 rpm). At 115 °C, in step i-2), 982.4 g of propylene oxide (alkylene oxide (A-2)) were metered into the headspace of the reactor over a period of 3.97 h. After an initial post-reaction phase at 115 °C lasting 4 h, during which the reactor pressure dropped from 4.2 bar to 1.5 bar, intermediate (D) was obtained.The temperature was increased to 130 °C, the reactor pressure was adjusted to 2.5 bar with nitrogen, and in step iii), 130.6 g of ethylene oxide (alkylene oxide (F)) were metered into the headspace of the reactor over a period of 0.52 h. After a second post-reaction phase at 130 °C lasting 1.05 h, during which the reactor pressure dropped from 3.4 bar to 2.7 bar, the contents of the autoclave were baked out at 130 °C in step iv) over a period of 48 min under vacuum (17 mbar), yielding the alkaline polyether polyol (H). After cooling to 80 °C, 726.5 g of the alkaline polyether polyol (H) were transferred to a glass reactor with double-jacketed heating and a stirred unit, and 162 ml of distilled water were added in step v). The ratio of water to alkaline polyoxyalkylene polyol was 0.22:1. Stirring was continued at 80 °C for a further 30 min. The stirrer was turned off and the reactor contents were allowed to stand at 80 °C for 24 h.After 24 h, 0.5 g of a lower (aqueous) phase and 877.0 g of an upper (predominantly polyether-containing) phase could be isolated, which corresponds to a weight ratio of the aqueous phase to the polyether polyol phase of 1 to 1754. The water content in the upper polyether polyol phase was 14.4 wt%.

[0195] Example 5 (inventive):

[0196] 90.5 g of the alkali metal alkoxylate of the glycerol-initiated polyoxyalkylene polyol from step i-1) were placed in a 2 l laboratory autoclave under a nitrogen atmosphere, and the autoclave was sealed. Oxygen was removed at room temperature by pressurizing the autoclave with nitrogen five times to an absolute pressure of 3 bar and then evacuating to 30 mbar. The contents of the autoclave were heated to 115 °C with stirring (cross-beam stirrer, 800 rpm). At 115 °C, in step i-2), 982.4 g of propylene oxide (alkylene oxide (A-2)) were metered into the headspace of the reactor over a period of 3.93 h. After a post-reaction phase at 115 °C lasting 4 h, during which the reactor pressure dropped from 3.9 bar to 1.4 bar, intermediate (D)) was obtained. The reactor contents were stripped at 115 °C in step ii) over a period of 5 h by introducing 50 ml of nitrogen / min while simultaneously applying vacuum, yielding intermediate (E).A pressure of 40 mbar was established. The temperature was then increased to 130 °C, and in step iii), 133.2 g of ethylene oxide (alkylene oxide (F)) were metered into the headspace of the reactor over a period of 0.57 h. After a second post-reaction phase at 130 °C lasting 1.0 h, during which the reactor pressure dropped from 1.6 bar to 0.3 bar, the contents of the autoclave were baked at 130 °C under vacuum (20 mbar) for 30 min, yielding the alkaline polyoxyalkylene polyol (H1). After cooling to 80 °C, 704.0 g of the alkaline polyether polyol (H) was transferred to a glass reactor with jacket heating and a stirrer, and 157 ml of distilled water were added in step iv). The ratio of water to alkaline polyoxyalkylene polyol was 0.22:1. Stirring was continued at 80 °C for a further 30 min. The stirrer was turned off, and the reactor contents were allowed to stand at 80 °C for 24 h.After 24 hours, 110.0 g of a lower (aqueous) phase and 740.0 g of an upper (predominantly polyether-containing) phase were isolated, corresponding to a weight ratio of the aqueous phase to the polyether polyol phase of 1 to 6.73. The water content in the upper polyether polyol phase was 5.4 wt%. Table 1: Summary of the results.

Claims

Patent claims 1. A process for producing a polyoxyalkylene polyol, preferably a polyether polyol, comprising the following steps: i) addition of an alkylene oxide (A) to an H-functional starter substance (B) in the presence of a basic catalyst (C) to form an intermediate (D), ii) vacuum treatment of the intermediate (D) at pressures of 1 mbara to 500 mbara, preferably from 2 mbara to 200 mbara, and particularly preferably from 2 mbara to 50 mbara to form an intermediate (E), iii) addition of an alkylene oxide (F) to the intermediate (E), optionally in the presence of a basic catalyst (G), to form an alkaline polyoxyalkylene polyol (H), preferably an alkaline polyether polyol (H1), iv) optionally vacuum treatment of the alkaline polyoxyalkylene polyol (H), preferably the alkaline polyether polyol (H1) at pressures of 1 mbara to 500 mbara, preferably from 2 mbara to 200 mbara, and particularly preferably from 2 mbara to 50 mbara,v) adding water and optionally an acid (I) to the alkaline polyoxyalkylene polyol (H), preferably to the alkaline polyether polyol (Hl) to form a mixture (J) comprising a first phase (Jl) containing the polyoxyalkylene polyol and a second, aqueous phase (J-2), vi) separating the second, aqueous phase (J-2) from the first phase (Jl) containing the polyoxyalkylene polyol by gravity, wherein the addition of the alkylene oxide (A) in step i) is terminated before the vacuum treatment in step ii) and the addition of the alkylene oxide (F) begins only after the completion of the vacuum treatment in step ii).

2. The process according to claim 1, wherein the alkylene oxide (A) is propylene oxide or a mixture of ethylene oxide and propylene oxide with up to 30 mass% ethylene oxide based on the total mass of the mixture of ethylene oxide and propylene oxide of the alkylene oxide (A).

3. Process according to claim 1 or 2, wherein the basic catalyst (C) is an alkali metal hydroxide, preferably sodium hydroxide and / or potassium hydroxide.

4. The process according to any one of claims 1 to 3, wherein step i) comprises the following substeps: il) addition of a first portion (A1) of the alkylene oxide (A) to the polyether polyol and / or the polyfunctional alcohol as H-functional starter substance (B) in the presence of the alkali metal hydride, the alkali metal carboxylate and / or the alkali metal hydroxide, preferably the alkali metal hydroxide, as basic catalyst (C) to form an alkali metal alkoxylate, i-2) reaction of the alkali metal alkoxylate with a second portion (A-2) of the alkylene oxide (A) to form the intermediate (D).

5. Process according to one of claims 1 to 4, wherein no water and / or acid addition takes place between steps i) and ii).

6. The process according to any one of claims 1 to 5, wherein after completion of the addition of the alkylene oxide (A) in step i) and before the vacuum treatment in step ii), the intermediate (D) is treated at a temperature of 80 °C to 150 °C, preferably from 80 °C to 115 °C and a pressure of 0.01 bara to 10 bara, preferably from 0.1 bara to 7 bara in a first post-reaction phase.

7. The process according to any one of claims 1 to 6, wherein the vacuum treatment in step ii) is carried out at temperatures of 20 to 200°C, preferably at 50 to 160°C, particularly preferably at 100°C to 150°C.

8. The process according to any one of claims 1 to 7, wherein the vacuum treatment in step ii) is carried out over a period of 5 min to 6 h, preferably 10 min to 4 h and particularly preferably 10 min to 2 h.

9. The process according to any one of claims 1 to 8, wherein the vacuum treatment in step ii) is carried out by introducing inert gases and / or water vapor, preferably nitrogen, below the liquid level into the intermediate (D).

10. The process according to claim 9, wherein the introduction of the inert gases and / or water vapor, preferably nitrogen, takes place in amounts of 1 mL / (min kg (intermediate (D))) to 50 mL / (min kg (intermediate (D))), preferably from 3 mL / (min kg (intermediate (D))) to 30 mL / (min kg (intermediate (D))) below the liquid level of the intermediate (D).

11. The process according to any one of claims 1 to 10, wherein the alkylene oxide (F) is ethylene oxide or a mixture of ethylene oxide and propylene oxide with at least 70 mass% ethylene oxide based on the total mass of the mixture of ethylene oxide and propylene oxide of the alkylene oxide (F).

12. The process according to any one of claims 1 to 11, wherein, after the addition of the alkylene oxide (F) in step iii) has ended, the alkaline polyoxyalkylene polyol (H), preferably the alkaline polyether polyol (H1), is treated in a second post-reaction phase at a temperature of from 80°C to 170°C, preferably from 80°C to 150°C and a pressure of from 0.01 bara to 10 bara, preferably from 0.1 bara to 7 bara.

13. The process according to any one of claims 1 to 12, wherein in step v) the mass ratio of added water to the alkaline polyoxyalkylene polyol (H) is from 0.07:1 to 0.7:1, preferably from 0.1:1 to 0.65:

1.

14. The process according to any one of claims 1 to 13, wherein in step v) the alkaline polyoxyalkylene polyol (H), preferably the alkaline polyether polyol (H1) is neutralized by adding water and the acid (I) to form the mixture (J) comprising the first phase (J1) containing the polyoxyalkylene polyol and a second aqueous phase (J-2) containing a neutralization salt.

15. The process according to any one of claims 1 to 14, wherein after step vi) in step vii) the water is separated from the first phase (Jl) containing the polyoxyalkylene polyol.

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