DE10147711A1 - Process for the preparation of polyether alcohols - Google Patents

Abstract

The invention relates to a method for the production of polyether alcohols from oxiran compounds in the presence of at least one multi-metal cyanide catalyst and a moderator gas selected from the group containing carbon dioxide, carbon monoxide, hydrogen and dinitrogen oxide or various mixtures of said gases at pressures of at least 1 bar, in addition to polyether alcohols obtained according to said method.

Description

The present invention relates to processes for the production of Polyether alcohols from oxirane compounds in the presence of Multimetal cyanide catalysts and those using these processes obtained polyether alcohols.

Industrial processes for the production of polyether alcohols from oxirane compounds are already known. polyether find, for example, in the manufacture of surfactants and Polyurethane foams and as a component of lubricants, Compressor fluids or paint coatings use. Of further polyoxymethylenes can be copolymerized by Stabilize polyether alcohols with formaldehyde or trioxane (see also WO 01/03830).

The ring-opening polymerization of oxirane compounds proceeds generally highly exothermic, regardless of whether one Alkali metal hydroxides as initiators or so-called Multimetal cyanide or DMC (Double Metal Cyanide) catalysts are used. Initiators based on alkali metal hydroxides are for this known to produce undesirable side reactions. You get Impurities in the polymer and often a wide one Molecular weight distribution. In addition, contain the so formed Polyether alcohols an undesirably high proportion of double bonds. Polyether alcohols can be used with DMC catalysts achieve a lower proportion of unsaturated units, too the molecular weights are generally greater than that of the Alkali hydroxide catalyzed polymerization, however, go with DMC catalysts are accompanied by relatively long induction phases, i. H. the actual polymerization can take between a few minutes and delay several hours. The DMC-catalyzed polymerization of oxirane compounds is not only because of this long Induction times especially for large-scale applications economically disadvantageous. Because of the strongly exothermic Character at the start of this reaction, which u. May also be explosive all reaction vessels and Equipment to meet special safety standards in order to "Runaway" reaction to sudden temperature and To prevent pressure increase. This is accompanied by no small number Investment costs for the construction of suitable plants.

Furthermore, it cannot be ruled out that after the Induction phase of briefly occurring high pressures and Temperatures not only the starting materials and the polymer product formed damage or to by-products and / or a broad Molecular weight distribution lead, but also decompose the catalyst or can deactivate. Because DMC catalysts usually not insignificant to the total cost of the To contribute to polyether alcohol production, it would be desirable to have any To prevent catalyst decomposition or the catalyst activity increase to with the lowest possible concentrations of catalyst get along.

WO 01/03830 describes a modified DMC catalyst with which the induction phase is shortened and the throttles exothermic character of the polymerization. This modified DMC catalysts have organic sulfoxide or To have sulfone ligands. It takes to manufacture them compared to conventional DMC catalysts an additional Process step. Organic sulfur compounds are above it extremely even in very low concentrations odor-intensive, which is why contamination of the polyether alcohol cannot be prevented regularly and washed out several times of the raw polymer product can entail.

Because of the great technical importance of polyether alcohols has recently been using alternative manufacturing processes searched. For example, Beckmann et al. (Polym. Prepr., Am. Chem. Soc., Div. Polym. Chem., 1999, 40, 903) Cyclohexene oxide in the presence of bulky aluminum complexes. Of Disadvantages are the long response times and the fact that for example ethylene oxide and propylene oxide among those described Conditions do not respond.

Inoue et al. polymerize oxirane compounds in the presence of Aluminum porphyrin systems in the presence or absence of Aluminum alkoxides. The disadvantage is that the used Due to their strong inherent color, catalyst complexes also become one Color the polymer product. The process also requires a photochemical activation stage and is therefore special not practicable for large-scale processes (see a. Macromolecules, 1994, 27, pp. 2820-2822; Macromol. Chem., Macromol. Symp., 1992, 64, pp. 151-158).

It would therefore be desirable to have a manufacturing process of polyether alcohols to be able to access the above does not have the disadvantages mentioned.

The present invention was therefore based on the object Process, in particular for the industrial production of To provide polyether alcohols, the minor Induction times made possible with conventional DMC catalysts is to be carried out and without expensive special equipment for protection against sudden pressure and / or temperature build-up.

Accordingly, a process for producing Polyether alcohols from oxirane compounds using multimetal cyanide Catalysts found in the presence of a moderator gas, selected from the group containing carbon dioxide, carbon monoxide, Hydrogen and nitrous oxide or any mixture these gases, is carried out at pressures of at least 1 bar.

The used for the method according to the invention Multimetal cyanide catalysts contain at least two per formula unit Metals, at least one metal being present as a cation and at least one metal with one or more cyanide ions and possibly other ligands is complexed. With exactly two metals as well at least one cyanide ion per formula unit is also referred to as Double metal cyanide catalysts or complexes (DMC).

Suitable multimetal cyanide compounds are known and in described the following A documents: US 3,278,457, US 3,278,458, US 3,278,459, US 3,427,256, US 3,427,334, US 3,404,109, US 3,829,505, US 3,941,849, EP 283,148, EP 385,619, EP 654,302, EP 659,798, EP 665,254, EP 743,093, EP 755,716, US 4,843,054, US 4,877,906, US 5,158,922, US 5,426,081, US 5,470,813, US 5,482,908, US 5,498,583, US 5,523,386, US 5,525,565, US 5,545,601, JP 7,308,583, JP 6,248,068, JP 4,351,632 and US 5,545,601.

Multimetal cyanide complexes are also e.g. B. in the scriptures DD-A 148 957, EP-A 862 947, EP-A 654 302, EP-A 700 949, WO-A 97/40086, WO-A 98/16310, EP-A 222 453, EP-A 90 444, EP-A 90 445, WO-A 01/04177, WO-A 01/04181, WO-A 01/04182, WO-A 01/03830, DE-A 199 53 546.

Particularly suitable multimetal cyanide catalysts are double metal cyanide compounds, in particular those of the formula (I)

M ¹ _a [M ² (CN) _b A _c ] _d .f M ¹ _g X _n .h H ₂ Oe Lk P (I)

The letters M, A, X, L and P stand for atoms or groups of atoms. CN and H ₂ O are cyanide and water. The superscript indices ¹ and ² are used to differentiate the different M. The subscript indices a, b, c, a, g, n are stoichiometric indices and the letters f, h, e and k are mole numbers.

In the general formula (I) mean
M ^{1 is} a metal ion selected from the group containing Zn ²⁺ , Fe ²⁺ . Fe ³⁺ , CO ²⁺ , CO ³⁺ , Ni ²⁺ , Mn ²⁺ , Sn ²⁺ , Pb ²⁺ , Mo ⁴⁺ , Mo ⁶⁺ , Al ³⁺ , V ⁴⁺ , V ⁵⁺ , Sr ^{2 +} , W ⁴⁺ , W ⁶⁺ , Cr ²⁺ , Cr ³⁺ , Cd ²⁺ , La ³⁺ , Ce ³⁺ , Ce ⁴⁺ , Eu ³⁺ , Mg ²⁺ , Ti ³⁺ . Ti ⁴⁺ , Ag ⁺ , Rh ²⁺ , Ru ²⁺ , Ru ³⁺ ,
M ^{2 is} a metal ion selected from the group comprising Fe ²⁺ , Fe ³⁺ , CO ²⁺ , CO ³⁺ , Mn ²⁺ , Mn ³⁺ , V ⁴⁺ , V ⁵⁺ , Cr ²⁺ , Cr ³⁺ , Rh ³⁺ , Ru ²⁺ , Ir ³⁺ ,
where M ¹ and M ^{2 can be the} same or different,
A at least one anion selected from the group consisting of halide, hydroxide, sulfate, hydrogen sulfate, carbonate, hydrogen carbonate, cyanide, thiocyanate, isocyanate, cyanate, carboxylate, oxalate, nitrate, nitrosyl, phosphate, dihydrogen phosphate, hydrogen phosphate,
X at least one anion selected from the group comprising halide, hydroxide, sulfate, carbonate, hydrogen carbonate, cyanide, thiocyanate, isocyanate, cyanate, carboxylate, oxalate, nitrate,
where A and X can be the same or different,
L at least one water-miscible ligand selected from the group consisting of alcohols, aldehydes, ketones, ethers, polyethers, esters, polyesters, polycarbonates, ureas, amides, nitriles, sulfides, amines, ligands with pyridine nitrogen, phosphides, phosphites, phosphines , Phosphonates, phosphates,
P at least one organic additive selected from the group comprising polyethers, polyesters, polycarbonates, polyalkylene glycol sorbitan esters, polyalkylene glycol glycidyl ethers, polyacrylamide, poly (acrylamide-co-acrylic acid), polyacrylic acid, poly (acrylamide-co-maleic acid), polyacrylonitrile, polyalkylacrylates, polyalkyl methacrylates, polyvinyl , Polyvinyl ethyl ether, polyvinyl acetate, polyvinyl alcohol, poly-N-vinylpyrrolidone, poly (N-vinylpyrrolodone-co-acrylic acid), polyvinyl methyl ketone, poly (4-vinylphenol), poly (acrylic acid-co-styrene), oxazoline polymers, polyalkyleneimines, maleic acid, maleic anhydride copolymer, Hydroxyethyl cellulose, polyacetets, ionic surface-active and surface-active compounds, bile acid and the salts, esters and amides of bile acid, carboxylic acid esters, polyhydric alcohols, glycosides,
where a, b, d, g and n are whole or fractional numbers greater than zero, and
where c, f, h, e and k are whole or fractional numbers greater than or equal to zero, and
where a, b, c, d, g and n are selected so that the electroneutrality of the cyanide compound M ¹ [M ² (CN) A] or the compound M ¹ X is ensured.

Formate, acetate and propionate are carboxylate groups A and X, respectively prefers.

The multimetal cyanide compounds can be crystalline or amorphous his. For k equals zero, the multimetal cyanide compounds are in usually crystalline or predominantly crystalline. Larger for k They are usually crystalline, semi-crystalline or in zero essentially amorphous.

The primary particles of the multimetal cyanide compounds point preferably a crystalline structure and a content of flaky particles of more than 30 wt .-%, based on the total weight of the multimetal cyanide compound. The Platelet shape of the particles leads to the proportion of catalytic active surface, based on the total surface, increases and thus the mass-specific activity increases.

Instead of platelet-shaped, the primary particles can also, for. B. rod-shaped, cube-shaped or spherical.

• - als M¹ mindestens ein Metallion, ausgewählt aus der Gruppe enthaltend Zn²⁺, Fe²⁺, Fe³⁺,
• - als M² mindestens ein Metallion, ausgewählt aus der Gruppe enthaltend Co²⁺, Fe²⁺, Fe³⁺,
• - als A Cyanidanion,
• - als X mindestens ein Anion, ausgewählt aus der Gruppe enthaltend Formiat, Acetat, Propionat,
• - als L mindestens einen mit Wasser mischbaren Liganden, ausgewählt aus der Gruppe enthaltend tert-Butanol, Monoethylenglykoldimethylether (Glyme)
• - als P Polyether.

Preferred multimetal cyanide compounds contain:

• as M ¹ at least one metal ion selected from the group comprising Zn ²⁺ , Fe ²⁺ , Fe ³⁺ ,
• as M ² at least one metal ion selected from the group comprising Co ²⁺ , Fe ²⁺ , Fe ³⁺ ,
• - as A cyanide anion,
• as X at least one anion selected from the group comprising formate, acetate, propionate,
• as L at least one water-miscible ligand selected from the group comprising tert-butanol, monoethylene glycol dimethyl ether (glyme)
• - as P polyether.

Multimetal cyanide compounds of the above are particularly preferred Formula (I) in which k and e are greater than zero. This Compounds contain the multimetal cyanide, at least one Ligand L and at least one organic additive P.

Multimetal cyanide compounds are also particularly preferred of formula (I) above, where k is zero and optionally e is zero. These compounds do not contain any organic Additive P and optionally no ligand L.

Multimetal cyanide compounds with k are very particularly preferred and e is zero, where X is selected from the group containing formate, acetate and propionate. These connections contain no organic additive P and no ligand L. Details can be found in WO-A 99/16775. At this Embodiment are crystalline double metal cyanide catalysts prefers; and double metal cyanide catalysts, which are crystalline and are platelet-shaped (see WO-A 00/74845).

Also particularly preferred are multimetal cyanide compounds of the formula (I) in which f, e and k are not equal to zero. I.e. these compounds contain the metal salt M ¹ _g X _n , a ligand L and organic additives P. See WO-A 98/06312.

The preparation of the multimetal cyanide compounds is e.g. B. described in WO-A 00/74843, WO-A 00/74844, WO-A 00/74845, EP-A 862 947, WO-A 99/16775, WO-A 98/06312 and US-A 5 158 922. An aqueous solution of the metal salt M ¹ _g X _{n is} usually combined with an aqueous solution of the cyanometalate H _a M ² (CN) _b A _c , where H is hydrogen, alkali metal, alkaline earth metal or ammonium. The metal salt solution and / or the cyanometalate solution can contain the water-miscible ligand L and / or the organic additive P. After combining the solutions, ligand L and / or additive P may be added. When preparing the catalyst, it is advantageous to stir vigorously, e.g. B. with high-speed stirrer. The precipitate is separated off in a conventional manner and, if necessary, dried.

The cyanometalates H _a M ² (CN) _b A _c with H equal to hydrogen (so-called cyanometalate hydrogen acids) can, for. B. on acidic ion exchangers from the corresponding alkali or alkaline earth metal cyanate, see z. B. WO-A 99/16775.

As in the older, unpublished DE application Az. 10009568.2, you can also start with an inactive one Prepare the catalyst phase and then through Convert recrystallization to an active phase.

Further details of the manufacturing process of the Those skilled in the art will find multimetal cyanide compounds in the two in the Writings mentioned above paragraphs.

A compound which can be obtained by reacting aqueous hexacyanocobaltoic acid H ₃ [Co (CN) ₆ ] with aqueous zinc acetate solution is very particularly preferably used as the multimetal cyanide compound.

The multimetal cyanide catalyst can be used in both anhydrous and non-anhydrous form. Preferred for the process according to the invention for the production of oligomeric polyether alcohols, in particular those with average molecular weights M _w , determined by means of gel permeation chromatography using tetrahydrofuran as eluent against a polystyrene standard, in the range from 500 to 4,000 g / mol, preferably from 1,000 to 3,500 g / mol , is the use of non-anhydrous multimetal cyanide catalysts. Non-anhydrous means that the catalyst contains, in addition to the chemically bound water (for example h mol of crystal water in the general formula (I) above), further water which is not chemically bound, in particular water which adheres to the surface or is physically enclosed in cavities. Accordingly, one speaks of an anhydrous catalyst if it contains only chemically bound water or if residual water is only present in very minor traces. Anhydrous multimetal cyanide catalysts are preferred for the synthesis of higher molecular weight polyether alcohols, in particular those with average molecular weights M _w , determined by means of gel permeation chromatography using hexafluoroisopropanol as eluent against a polymethyl methacrylate standard, above 4,000 g / mol, preferably in the range from 4,000 to 1,000,000 g / mol and particularly preferably in the range from 4,000 to 500,000 g / mol used according to the inventive method. For example, polyether alcohols with molecular weights M _w in the range from 4,000 to 30,000 g / mol are readily accessible with anhydrous multimetal cyanide catalysts.

In order to obtain an anhydrous catalyst, it is heated generally before the start of the polymerization in an inert gas stream or in a vacuum until water-free. Commonly used nitrogen, argon or other customary inert gases are used as the inert gas. The temperature up to which the catalyst is heated is usually 80 to 130 ° C. The duration of the heating is usually 20 to 300 min. Typical values are 4 hours at 130 ° C for multimetal cyanide catalysts. You can do that Place the catalyst in the polymerization reactor, in an inert gas stream make anhydrous (bake out) and - if necessary after cooling - in carry out the polymerization in the same reactor.

However, the catalyst can also be heated by vacuum or other suitable drying methods, e.g. B. by removal of an azeotropic mixture from water and Toluene, make anhydrous.

Furthermore, the multimetal cyanide catalyst can also be one Be subjected to shearing.

As such, the multimetal cyanide catalyst can be in solution or in dispersion or suspension for the inventive Procedures are used. In a further embodiment can the multimetal cyanide catalyst on a solid, inert Carrier material applied or introduced into this. Also can this catalyst with or without support material too Shaped bodies are shaped or are in powder or paste form and used in this form for catalysis.

Ethylene oxide and substituted epoxides are suitable as oxirane compounds. These are usually those compounds which come under the following general formula (II):

The radicals R here independently of one another denote hydrogen, halogen, nitro group -NO ₂ , cyano group -CN, ester group -COOR or a hydrocarbon group with 1 to 32 C atoms, which can be substituted.

Preference is given to geminally substituted epoxides, particularly preferably on epoxides substituted only in the 1-position resorted.

Suitable hydrocarbon groups are, for example, C _1-32 alkyl such as methyl, ethyl, i- or n-propyl, i-, n- or t-butyl, n-pentyl or n-hexyl, C _2-20 alkenyl such as propenyl or butenyl , C ₃ -C ₂₀ cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl, C _6-18 aryl such as phenyl or naphthyl, and C _7-20 arylalkyl, e.g. B. Benzyl. And wherein two radicals R, when they are located on different carbon atoms of the epoxy group may be bridged to each other and so form a C _3-20 cycloalkylene group.

The following groups are particularly suitable as substituents with which the C _1-32 hydrocarbon group can be substituted: halogen, cyano, nitro, thioalkyl, tert-amino, alkoxy, aryloxy, arylalkyloxy, carbonyldioxyalkyl, carbonyldioxyaryl, carbonyldioxyarylalkyl, alkoxycarbonyl, Aryloxycarbonyl, arylalkyloxycarbonyl, alkylcarbonyl, arylcarbonyl, arylalkylcarbonyl, alkylsulfinyl, arylsulfinyl, arylalkylsulfinyl, alkylsulfonyl, arylsulfonyl and arylalkylsulfonyl.

Ethylene oxide is preferably used as the oxirane compound, Propylene oxide, butylene oxide (1-butene oxide, BuO), cyclopentene oxide, Cyclohexene oxide (CHO), cycloheptenoxide, 2,3-epoxypropylphenyl ether, epichlorohydrin, epibromohydrin, i-butene oxide (IBO), Styrene oxide or acrylic oxides. It is particularly preferably used Ethylene oxide (EO), propylene oxide (PO), butylene oxide, cyclopentene oxide, Cyclohexene oxide or i-butene oxide. Very particularly preferred Ethylene oxide, propylene oxide, i-butene oxide or any of them Mixtures. Terminal oxirane compounds also come with long-chain radicals R, for example epoxidized Soybean oil. It is understood that mixtures of the aforementioned Epoxies can be used, which leads to Copolyether alcohols, for example with statistically distributed ethoxy and propoxy units.

The oxirane compounds can be used both as a racemate and in optically enriched or enantiomerically pure or diastereomerically pure form can be used.

The aforementioned oxirane compounds are known to those skilled in the art generally known and are usually also commercially available. Optically enriched or enantiomerically pure oxirane compounds can be in a known manner by means of resolution, to Example of HPLC chromatography columns with chiral column material, receive. Furthermore, such oxirane compounds are made directly terminal olefins via stereospecific epoxidations accessible (see also J. Am. Chem. Soc. 1987 (109) p. 5765 ff and 8120 ff; and "Asymmetric Synthesis, ed. J. D. Morrison, Academic Press, New York, 1985, Vol. 5, Chapters 7 and 8).

The method according to the invention is usually used in Temperatures in the range from 50 to 110 ° C, preferably from 65 to 90 ° C carried out. But it can also at room temperature, that is in Range of 15 to 25 ° C, are carried out. Usually it is not required to cool the polymer reaction, however is also implemented at lower temperatures Room temperature, that is in the range of, for example, 0 to 15 ° C instead of.

Based on the catalyst solution or dispersion (sum of The catalyst and inert reaction medium) is the Catalyst concentration preferably 0.0001 to 20, in particular 0.001 to 10% by weight. Based on the total of catalyst, epoxy and inert Reaction medium, the catalyst concentration is preferred 0.001 to 20, particularly preferably 0.001 to 1 wt .-%.

The polyether alcohol production according to the invention can be carried out in bulk, Dispersion, suspension or in solution. The polymerization is preferably carried out on an industrial scale in bulk instead. If the polymerization is in solution, suspension or dispersion is carried out, one particularly picks up inert aromatic reaction media such as benzene, toluene, xylenes or anisole back. Furthermore, as inert Reaction media also aliphatic hydrocarbons, such as hexane or Cyclohexane, halogenated hydrocarbons, such as dichloromethane, Chloroform or isobutyl chloride, or ethers, such as dimethoxyethane, Diethylene glycol dimethyl ether, dioxane, diethyl ether or Tetrahydrofuran. Nitro compounds are also like Nitromethane or nitrobenzene suitable. Of course come also any mixtures of the aforementioned reaction media in Question. Toluene and cyclohexane are particularly preferred used.

In a further embodiment, the bulk, solution, Polymerization carried out in suspension or dispersion, especially in the production of oligomeric polyether alcohols, too in the presence of a low molecular weight organic compound containing at least two, three or more free hydroxy groups and / or in the presence of liquid polyether alcohols with a average molecular weight in the range from 40 to 1000 g / mol, preferably from 400 to 900 g / mol. Prefers are used as low molecular weight organic compounds low molecular weight di- or polyols with preferably two to ten Carbon atoms in the chain, e.g. B. glycol, glycerin or Pentaerythritol. For example, the liquid polyether alcohols by the oligomerization of ethylene oxide or propylene oxide or their mixtures are obtained. Suitable as a liquid Polyether alcohols are e.g. B. commercially available Polyethylene glycols such as the products under the Lutrol®E brand (BASF AG) as well Polypropylene glycols such as the products under the Pluriol®P brand (BASF AG). The low molecular di- or polyols or liquid Polyether alcohols can act as starters and form Starting points for the polyether alcohol synthesis according to the invention. In this way you get star-like or so-called Graft. The latter are generally characterized by a comb-like structure.

In the method according to the invention, the ring-opening Polymerization of the oxirane compounds in the presence of a Moderator gas, selected from the group containing carbon dioxide, Carbon monoxide, hydrogen and nitrous oxide or one any mixture of these gases. These gases are below the reaction conditions in the reaction vessel in general Pressures of at least 1 bar, preferably in the range from 1 to 40 bar, preferably from 1.5 to 20 bar and particularly preferably from 1.5 to 10 bar. The minimum pressure of moderator gas in the Reaction vessel with which a start of polyether alcohol formation, d. H. an extreme acceleration of reaction due to a sudden pressure and / or temperature rise can still be prevented can depend essentially on the amount used Multimetal cyanide catalyst and the concentration Oxirane compound in the reaction mixture. This in small dimensions Preliminary tests can generally be carried out without further transferred to large-scale systems. For example is sufficient at a concentration of multimetal cyanide catalyst of 0.6% by weight, based on the total weight of the used Oxirane compound, and a ratio of oxirane compound to Solvents of 1: 1 (vol / vol) already have a carbon dioxide pressure from 2 bar to a sudden rise in pressure and temperature completely prevented at the start of polyether alcohol formation.

Usually you give the moderator gas, e.g. B. carbon dioxide, gaseous in the reaction vessel, the amount of which - in Dependence on the temperature - is set via the gas pressure. at Room temperature (23 ° C) in the reactor is the moderator gas pressure the addition of the oxirane compound is preferably 1 to 30, especially preferably 1 to 20 bar and in particular 1 to 10 bar, each at 23 ° C.

All pressure specifications are absolute prints. The moderator gas pressure can discontinuously at once or divided into several steps, can be set, or continuously via a certain period linear or a linear exponential or following gradual gradients.

The response time is usually small Try 60 to 500 min. preferably 60 to 300 min.

The gases carbon monoxide used as moderator gases, Carbon dioxide, hydrogen and thick matter oxide are sufficient for the person skilled in the art known and commercially available.

At the beginning of the implementation, the Multimetal cyanide catalyst, the solvent and the oxirane compound in the Reaction vessel submitted, the order is not significant is. Before dosing the oxirane compounds, this is Reaction vessel is usually rendered inert to prevent undesirable reactions Avoid oxirane compounds with oxygen. Subsequently become carbon dioxide, carbon monoxide, hydrogen, nitrous oxide or any mixtures of these gases and the desired pressure and / or the desired temperature. Furthermore, solvents, oxirane compound or Catalyst even under a moderator gas atmosphere in the Reaction vessel are introduced.

Instead of presenting the multimetal cyanide catalyst, one can also initially the inert reaction medium (if not in bulk should be polymerized), then the oxirane compound and then either the moderator gas or the multimetal cyanide Add catalyst.

In a preferred embodiment, a multimetal cyanide Catalyst introduced into the reaction vessel and optionally heated under vacuum to remove any remaining water, if you want to work with an anhydrous catalyst. Then, if the reaction is not in bulk, one gives to be carried out, an inert reaction medium, for example Toluene, for multimetal cyanide catalyst. After adding the Oxirane compound becomes the moderator gas in the reaction vessel given and the reaction temperature set. After reaching the desired reaction temperature, the desired pressure of the Moderator gas can still be adjusted.

The polymerization is generally carried out by cooling, relaxing the reaction vessel and dilute the reaction mixture with an inert solvent, for example tetrahydrofuran or Methanol, terminated and, if necessary, by known methods worked up.

If the process according to the invention is carried out on an industrial scale By scale, is usually polymerized in bulk. The amount catalyst residues in the polymer do not fall further weight, which is why there are no further processing steps can be. For smaller batches, you can use the catalyst e.g. B. filter out of the reaction mixture (if not in bulk has been worked), extract, e.g. B. in the absorber bed Silica, or bind to ion exchangers.

With the method according to the invention polyether alcohols can Molecular weights in the range of 500 to 1,000,000 g / mol be preserved. So-called oligomeric polyether alcohols, in particular those with MW molecular weights in the range of 1,000 to 4,000 g / mol are especially with non-anhydrous multimetal cyanide Easily accessible catalysts. High molecular weight polyether alcohols, especially those with molecular weights in the range of 5,000 up to 500,000 g / mol can preferably be obtained with anhydrous Receive catalysts, with small amounts of anhydrous or almost anhydrous multimetal cyanide catalyst suffice. The synthesis is also favored higher molecular weight polyether alcohol when the reaction medium is very small amounts, preferably less than 500 ppm, of reactive Connections such as B. contains water or alcohols.

The polyether alcohols obtained by the process according to the invention, when carbon dioxide is used as moderator gas, are distinguished by the fact that they contain no or only a small proportion of incorporated carbonate units. The proportion of carbonate units is generally well below 50 mol%, preferably in the range up to a maximum of 30 mol% and particularly preferably in the range up to a maximum of 20 mol%, based on the polyether alcohol obtained. The proportion of carbonate linkages in the polymer is generally determined on the basis of ¹ H-NMR spectra. For the purposes of the present invention, polyether alcohols are accordingly also those polyether alcohols with a maximum of 30% of statistically incorporated carbonate units. No installation takes place when using carbon monoxide, hydrogen, nitrous oxide or mixtures thereof. Homopolymeric polyether alcohols are obtained.

With the inventive method for the production of Polyether alcohols from oxirane compounds in the presence Otherwise, multimetal cyanide catalysts can do this in this reaction observed go-around, d. H. the sudden rise of Temperature and pressure after an unpredictable Induction time can be completely prevented. This way, too the industrial production of polyether alcohols Oversized security standards, for example at Design of valves, reactors or supply and discharge lines to be dispensed with, which increases the investment costs for the construction suitable systems can be significantly reduced. Furthermore, it is possible to install carbonate units in the Polyether alcohol structure when using carbon dioxide as moderator gas completely or almost completely. In particular is it is possible with the method according to the invention, specifically Polyether alcohols with small proportions of statistically distributed To produce carbonate units. This is when using So far, DMC catalysts have often failed due to the fact that one Could not prevent the reaction from starting. The one there occurring high pressures and temperatures lead to higher installation rates on carbonate units.

Those obtained by the process according to the invention Polyether alcohols, especially the oligomeric polyether alcohols, can in a known manner, for example with polyisocyanates Polyurethanes are implemented and are therefore particularly suitable for the production of polyurethane foams, in particular Flexible polyurethane foams, and thermoplastic polyurethanes.

Details on polyurethane production based on Polyether alcohols are described in DE-A 10 00 1779 to which reference is hereby expressly made. Furthermore are out these polyether alcohols surfactants and lubricants, Compressor fluids or paint coatings accessible. Moreover can be polyoxymethylenes by copolymerization of Stabilize polyether alcohols with formaldehyde or trioxane.

From the molding compositions preferably containing non-oligomeric Polyether alcohols in the sense of the invention can be moldings of all Art, including foils, films, coatings and fabrics as well Make fibers. The production of the foils can be done by Extruding, rolling, calendering and others known to those skilled in the art Procedure. The molding compositions according to the invention by heating and / or friction alone or with joint use from softening or other additives to one processable film or sheet (plate) shaped. Processing into three-dimensional moldings for everyone Type is done for example by injection molding.

As coatings come e.g. B. coatings from surfaces Paper, wood, plastic, metal or glass.

The present invention is based on the following examples are explained in more detail.

Examples

There were carbon dioxide, toluene, propylene oxide and cyclohexene oxide from BASF AG, Ludwigshafen. Toluene was added before Use refluxed over sodium for several hours distilled immediately before addition to the reaction vessel.

The double metal cyanide catalyst (DMC) was prepared as follows:
In a stirred tank with a volume of 800 l, equipped with a inclined blade turbine, dip tube for dosing, pH electrode, conductivity measuring cell and scattered light probe, 370 kg of aqueous hexacyanocobaltoic acid H ₃ [Co (CN) ₆ ] (cobalt content 9 g / l ) submitted and heated to 50 ° C with stirring. Subsequently, 209.5 kg of aqueous zinc acetate dihydrate solution (zinc content 2.7% by weight), which was also heated to 50 ° C., were metered in with stirring (stirring power 1 W / l) within 50 min. 8 kg of Pluronic® PE 6200 (this is an EO-PO block copolymer with 20% by weight of EO and an average molecular weight of about 2000 to 5000, available from BASF) and 10.7 kg of water were then added with stirring. Then 67.5 kg of aqueous zinc acetate dihydrate solution (zinc content: 2.7% by weight) were metered in with stirring (stirring energy: 1 W / l) at 50 ° C. within 20 min. The suspension was stirred at 55 ° C. until the pH had dropped from 3.7 to 2.7 and remained constant. The precipitation suspension thus obtained was then filtered off by means of a filter press and washed in the filter press with 400 l of water. The moist filter cake obtained was dried in a forced air oven at 60 ° C. to constant weight.

test description

The DMC catalyst was introduced into the reaction vessel (5 ml) and heated at temperatures in the range from 80 to 130 ° C. over a period of 4 hours. After cooling to room temperature under a nitrogen atmosphere, toluene and propylene oxide were added, the reaction vessel was closed and carbon dioxide was injected to the desired pressure. The polymerization reactor was heated to 80 ° C. and held at this temperature for 3 hours. After cooling to room temperature, the reaction reactor was depressurized, the reaction mixture was taken up in tetrahydrofuran (2-5 ml), the polyether alcohol formed was filtered off and the last solvent residues were removed using ultrasound and then vacuum at 80 ° C. over a period of 12 hours. The amounts of catalyst, toluene and oxirane compound used and the carbon monoxide pressure applied are recorded in the table below. The pressure and temperature values were continuously recorded and documented throughout the reaction time, namely with a pressure sensor of type 881.09.5295 from WIKA and with a temperature sensor of type PT 100 using a data acquisition device of type LSB 36 III from Linseis.

Claims (18)

1. A process for the preparation of polyether alcohols from oxirane compounds in the presence of multimetal cyanide catalysts, characterized in that the polymerization reaction in the presence of a moderator gas selected from the group comprising carbon dioxide, carbon monoxide, hydrogen and nitrous oxide or any mixtures of these gases, at pressures of at least 1 bar. 2. The method according to claim 1, characterized in that one the polymerization reaction at pressures in the range of 1.5 up to 20 bar. 3. The method according to claims 1 or 2, characterized characterized in that as oxirane compounds ethylene oxide, Propylene oxide, i-butene oxide or mixtures thereof. 4. The method according to claims 1 to 3, characterized characterized in that one as a multimetal cyanide catalyst Double metal cyanide catalyst used. 5. The method according to claims 1 to 4, characterized characterized in that the polymerization in bulk, suspension, Performs dispersion or in solution. 6. The method according to claims 1 to 5, characterized characterized that you have a non-anhydrous Multimetal cyanide catalyst is used. 7. The method according to claim 6, characterized in that the polyether alcohol has an average molecular weight M _w in the range from 500 to 4,000 g / mol, determined by means of gel permeation chromatography using tetrahydrofuran as eluent against a polystyrene standard. 8. The method according to claims 6 or 7, characterized characterized in that the polymerization in the presence of a low molecular weight organic compound containing at least two free hydroxy groups and / or liquid in the presence Polyether alcohols with an average molecular weight in the range from 40 to 1000 g / mol. 9. The method according to claims 1 to 5, characterized characterized that you have an anhydrous Multimetal cyanide catalyst is used. 10. The method according to claim 9, characterized in that the polyether alcohol has an average molecular weight M _w in the range from 4,000 to 1,000,000 g / mol, determined by means of gel permeation chromatography using hexafluoroisopropanol as eluent against a polymethyl methacrylate standard. 11. The method according to claims 1 to 10, characterized characterized in that carbon dioxide is used as the moderator gas. 12. The method according to claim 11, characterized in that the Percentage of carbonate units in polyether alcohol in Range is up to 20 mol%. 13. Polyether alcohols obtainable according to one of claims 1 to 12th 14. Polyether alcohols obtainable according to one of claims 6 or 7. 15. Polyether alcohols obtainable according to claim 8. 16. Polyether alcohols obtainable according to one of claims 9 or 10. 17. Use of the polyether alcohols according to claims 14 or 15 for the production of polyurethane foams, thermoplastic polyurethanes, surfactants, lubricants, Compressor liquids or paint coatings or Stabilization of polyoxymethylenes. 18. Use of the polyether alcohols according to claim 16 for the Production of moldings, foils, films, coatings or fibers.