WO2004022227A1 - Method for the production of multimetal cyanide catalysts - Google Patents

Abstract

The invention relates to a method for producing multimetal cyanide compounds, comprising the following steps a) reacting a metal salt of the aqueous solution with the aqueous solution of a cyanometallate compound, b) spray drying the suspended multimetal cyanide compounds obtained in step a).

Description

Process for the preparation of multimetal cyanide catalysts

description

The invention relates to a process for the preparation of multimetal cyanide compounds, the multimetal cyanide compounds prepared by this process and their use as catalysts for the polymerization of alkylene oxides.

Polyether alcohols are used in large quantities for the production of polyurethanes. They are usually produced by catalytic addition of lower alkylene oxides, in particular ethylene oxide and propylene oxide, to H-functional starter substances. Basic metal hydroxides or salts are mostly used as catalysts, the potassium hydroxide being of the greatest practical importance.

In the synthesis of polyether alcohols with long chains, such as are used particularly for the production of flexible polyurethane foams, side reactions occur as the chain grows, which leads to disruptions in the chain structure. These by-products are referred to as unsaturated components and lead to an impairment of the properties of the resulting polyurethanes. There has been no shortage of attempts in the past to provide polyether alcohols with a low content of unsaturated constituents. To this end, the alkoxylation catalysts used are specifically modified. It is proposed in EP-A-268 922 to use cesium hydroxide as the catalyst. So that can

Unsaturated content can be reduced, but cesium hydroxide is expensive and problematic to dispose of.

Furthermore, the use of multimetal cyanide complex compounds, mostly zinc hexacyanometalates, for the production of polyether alcohols with low levels of unsaturated constituents is known. There are a large number of documents describing the preparation of polyether alcohols using multimetal cyanide complex compounds as catalysts. DD-A-203 735 and DD-A-203 734 describe the production of polyetherols using zinc hexacyano cobaltate.

The production of zinc hexacyanometalates is also known. These catalysts are usually prepared by solutions of metal salts, such as zinc chloride, with solutions of alkali metal or alkaline earth metal cyanometalates, such as potassium hexacyanoates. cobaltat, to be implemented. A water-miscible, heteroato-containing component is generally added to the precipitation suspension formed immediately after the precipitation process. This component can also already be present in one or in both educt solutions. This water-miscible component containing heteroatoms can be, for example, an ether, polyether, alcohol, ketone or a mixture thereof. Such methods are described for example in US 3,278,457, US 3,278,458, US 3,278,459 and US 5,545,601.

Although multimetal cyanide catalysts have high polymerization rates, there has been no lack of attempts to further increase the catalytic activity of the multimetal cyanide compounds.

Multimetal cyanide catalysts are mostly used in the form of powder for the production of polyether alcohols. No. 5,900,384 describes a process for producing multimetal cyanide catalysts with improved catalytic activity and small particle size, in which a slurry of multimetal cyanide compounds is dried in an organic solvent by means of spray drying. A disadvantage of this process is that the slurrying of the multimetal cyanide compound in the organic solvent represents an additional process step, which makes the process more complicated. In addition, because of the risk of explosion of the organic solvents, the spray drying must be carried out under an inert gas atmosphere. Furthermore, it has been shown that the multimetal cyanide catalysts produced in this way still have an insufficient catalytic activity.

The object of the invention was to provide multimetal cyanide compounds which have high catalytic activity and can be prepared by a simple process.

It has surprisingly been found that multimetal cyanide compounds show an increased catalyst activity in the polymerization of alkylene oxides when they are spray-dried from an aqueous suspension and under an inert gas or air. The invention accordingly relates to a process for the preparation of multimetal cyanide compounds, comprising the steps

a) reacting one of the aqueous solution of metal salts with the aqueous solution of a cyanometalate compound,

b) spray drying the suspended multimetal cyanide compounds obtained in step a).

The invention furthermore relates to the multimetal cyanide compounds obtained by this process.

The invention further relates to the use of the multimetal cyanide compounds prepared by this process as catalysts for the preparation of polyether alcohols by polymerizing alkylene oxides.

The multimetal cyanide compounds produced by the process according to the invention preferably have the general formula (I)

M ¹ _a [M ² (CN) _b (A) _c ] _d -fM ¹ _g X _n -h (H ₂ 0) eL-kP (I),

in which

M ^{1 is} a metal ion selected from the group comprising Zn ²⁺ , Fe ²⁺ , Co ³⁺ , Ni ²⁺ , Mh ² X Co ²⁺ , Sn ²⁺ , Sn ⁴⁺ , Pb ²⁺ , Mo ⁴⁺ , Mo ⁵⁺ , Al ³⁺ , V ⁴ X ⁵⁺ , Sr +, W ⁴⁺ , W ⁶⁺ , Cr ² +, Cr ³⁺ , Cd ²⁺ , Cu ²⁺ , La ³⁺ ,

M ^{2 is} a metal ion selected from the group containing Fe ²⁺ , Fe ³⁺ , Co ²⁺ , Co ³⁺ , Mh ²⁺ , Mn ³⁺ , Ni ⁺ V ⁺ , V ⁵⁺ , Cr ²⁺ , Cr ^{3 +} , Rh ³ X Ru ² +, Ir ⁺ ,

mean and M ¹ and M ^{2 are} different,

A is an anion selected from the group consisting of halide, hydroxide, sulfate, carbonate, cyanide, thiocyanate, isocyanate, cyanate, carboxylate, oxalate or nitrate,

X is an anion selected from the group consisting of halide, hydroxide, sulfate, carbonate, cyanide, thiocyanate, isocyanate, cyanate, carboxylate, oxalate, nitrate or nitrite (N0 ₂ ^~ ), and the uncharged species CO, H0 and NO, L is a water-miscible ligand selected from the group consisting of alcohols aldehydes, ketones, ethers, polyethers, esters, polyesters, polycarbonates, ureas, amides, nitriles, and sulfides or mixtures thereof,

P is an organic additive selected from the group consisting of 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, polyalkyl - Acrylates, polyalkyl methacrylates, polyvinyl methyl ether, poly vinyl ethyl ether, poly vinyl acetate, poly vinyl alcohol, poly-N-vinyl pyrrolidone, poly (N-vinyl pyrrolidone-co-acrylic acid), poly vinyl methyl ketone, poly (4-vinyl phenol), poly (acrylic acid co-styrene ), Oxazoline polymers, polyalkyleneimines, maleic acid and maleic anhydride copolymer, hydroxyethyl cellulose, polyacetates, ionic surfaces and surface-active compounds, bile acid or its salts, esters or amides, carboxylic acid esters of polyhydric alcohols and glycosides,

such as

a, b, d, q and n are integer or fractional numbers greater than zero, c, f, e, h and k are integer or fractional numbers greater than zero,

in which

a, b, c, and d, and q and n are selected so that electroneutrality is ensured.

Preferably, f and k may only be zero if c is non-zero and A is exclusively carboxylate, oxalate or nitrate.

These catalysts can be crystalline or amorphous. In the event that k is zero, crystalline double metal cyanide compounds are preferred. In the event that k is greater than zero, both crystalline, partially crystalline and substantially amorphous catalysts are preferred.

To carry out the process according to the invention, an aqueous solution of a cyanometalate compound, in particular a cyanometalate hydrogen acid or a cyanometalate salt, is combined with the aqueous solution of a metal salt of the general formula M ^ fXJn, where the symbols have the meaning explained above. This is done with a stoichiometric shot of the metal salt worked. The molar ratio of the metal ion to the cyanometalate component is preferably from 1.1 to 7.0, preferably from 1.2 to 5.0 and particularly preferably from 1.3 to 3.0. It is advantageous to present the metal salt solution and add the cyanometalate compound, but the procedure can also be reversed. Thorough mixing, for example by stirring, is required during and after the starting material solutions have been combined.

The content of the cyanometalate compound in the aqueous solution, based on the mass of aqueous solution, is 0.1 to 30% by weight, preferably 0.1 to 20% by weight, in particular 0.2 to 10% by weight. The content of the metal salt component in the metal salt solution, based on the mass of metal salt solution, is 0.1 to 50% by weight, preferably 0.2 to 40% by weight, in particular 0.5 to 30% by weight.

At least one of the aqueous solutions of the starting materials preferably contains a ligand containing heteroatoms, as it is designated and explained as L in the general formula (I). The ligands containing heteroatoms can also be added to the resulting suspension only after the two starting material solutions have been combined, and here too thorough mixing must be ensured.

The content of the ligands containing heteroatoms in the suspension formed after the precipitation should be 1 to 60% by weight, preferably 5 to 40% by weight, in particular 10 to 30% by weight.

To adjust the morphology of the multimetal cyanide compounds, it has proven useful to carry out the preparation of these compounds in the presence of surface-active substances. As a rule, the surface-active substances are already introduced in at least one of the two solutions. The surface-active substances are preferably added to the solution which is initially introduced during the precipitation. The content of surface-active substances in the precipitation solution, based on the total mass of the precipitation suspension, is preferably between 0.01 and 40% by weight, in particular between 0.05 and 30% by weight. Another preferred embodiment provides that the surface-active substances are distributed proportionally to both educt solutions.

In a further preferred embodiment of the preparation of the multimetal cyanide compounds, the reaction of the metal salt with the cyanometalate compound (step a) takes place in two stages. First, a catalytically inactive phase of the multimetal cyanide compound is produced and then this converted into a catalytically active phase of the multimetal cyanide compound by recrystallization. The recrystallization can be carried out by various measures. It is thus possible to add further reactant solutions, in particular the solution of the metal salt, to the suspension formed after the reaction. Another possibility is to change the temperature of the precipitation suspension after the precipitation has ended, in particular to heat the suspension. Another possibility is to add further heteroatoms containing ligands and / or surface-active substances to the precipitation suspension after the precipitation has ended. Another possibility is to change the pH of the precipitation suspension.

In a further preferred embodiment of the method according to the invention, k is zero in formula (I) and optionally e is also zero. In this case, X is exclusively carboxylate, preferably formate, acetate and propionate. Such multimetal cyanide compounds are described, for example, in WO 99/16775. In this embodiment, crystalline double metal cyanide catalysts are preferred.

Multimetal cyanide compounds which are crystalline and platelet-shaped are also preferred. Such multimetal cyanide compounds are described, for example, in WO 00/74843.

In a further preferred embodiment of the multimetal cyanide compounds, f, e and k in formula (I) are not equal to zero. These are multimetal cyanide compounds which contain a water-miscible organic ligand L, mostly in amounts of 0.5 to 30% by weight, and an organic additive P, usually in amounts of 5 to 80% by weight , Such multimetal cyanide compounds are described, for example, in WO 98/06312. described.

The precipitation of the multimetal cyanide compounds in step a) can preferably be carried out with vigorous stirring, for example at 24,000 rpm with Turrax® stirring, as described, for example, in US Pat. No. 5,158,922.

Further for carrying out the method according to the invention preferred multimetal cyanide, as described in WO 01/03830, describes contain organic sulphones or sulphoxides ^■. Further multimetal cyanide compounds preferred for the process according to the invention can, as described in WO 01/03831, be produced by a so-called "Incipient Wetness Method". Others for the inventive Preferred multimetal cyanide compounds can, as described in WO 01/04182, contain metal hexacyanometallate hexanitro metalate, or, as described in WO 01/04181, contain hexacyano cobaltate nitroferrocyanide.

Between steps a) and b), the multimetal cyanide compounds produced in step a) can be separated from the precipitation suspension by filtration or centrifugation. One or more washes of the multimetal cyanide compounds can then follow this separation. The washings can be carried out with water, the ligands containing heteroatoms mentioned above or mixtures thereof. The washings can be carried out on the separation device (e.g. filter device) itself or in separate apparatus by e.g. Resuspend the multimetal cyanide compound in washing liquid and separate again from the liquid. This washing can be carried out at temperatures from 10 ° C. to 150 ° C., preferably 15 ° to 60 ° C.

The multimetal cyanide compound thus obtained is optionally mashed with water, the solids content being adjusted in such a way that a sprayable aqueous suspension is present. The solids content of the suspension is then between 5 and 40% by weight. The aqueous suspension of the multimetal cyanide compounds is then converted into a powdery solid by a spray drying process, as described, for example, in Kröll, drying technology, Springer Verlag, 2nd volume, 2nd edition, pages 275-313. The aqueous suspension is first divided into fine droplets in the spray dryer by means of an atomizing device, such as a one-component nozzle, two-component nozzle, or a rotary atomizer, which are then dispersed in a hot gas stream. The inlet temperature of the drying gas is preferably between 120 ° C and 350 ° C. Due to the intensive heat and mass exchange of the spray droplets with the hot drying gas, the liquid evaporates from the spray droplets into the drying gas, so that a dry powdery solid is obtained. At the outlet of the spray dryer, the dried spray powder is separated from the drying gas, for example with a filter or cyclone. Since the metal cyanide compounds are dried from aqueous solution, the safety requirements for the spray drying process are considerably lower than in the presence of organic solvents. In principle, all gases which are inert to the multimetal cyanide compounds under the drying conditions can be used as drying gases. Air, nitrogen or argon are used in particular.

Air can be used particularly preferably as the drying gas, which leads to a significantly higher activity of the catalyst compared to nitrogen.

The multimetal cyanide compounds prepared by the process according to the invention are outstandingly suitable as catalysts for the synthesis of polyetherols with functionalities from 1 to 8, preferably 1 to 6 and molar masses from 500 to 50,000, preferably 800 to 15,000, by addition of alkylene oxides onto H-functional starter substances. The catalyst concentrations used are less than 1% by weight, preferably less than 0.5% by weight, particularly preferably less than 1000 ppm, particularly preferably less than 500 ppm, particularly preferably less than 100 ppm, based on the total mass of the polyetherol Polyetherols can be carried out either continuously or batchwise. The synthesis is carried out in a suspension mode. The temperatures used in the synthesis are between 50 ° C. and 200 ° C., temperatures between 90 ° C. and 150 ° C. being preferred.

To prepare the polyether alcohols using the catalysts according to the invention, compounds having at least one alkyl oxide group, such as, for example, ethylene oxide, 1, -epoxypropane (propylene oxide), 1, 2-methyl-2-methylpropane, 1,2-epoxybutane (butylene oxide), 2, 3-epoxybutane, 1,2-epoxy-3-methylbutane, 1,2-epoxypentane, 1,2-epoxy-3-methylpentane, 1, 2-epoxyhexane, 1, 2-epoxyheptane, 1, 2-epoxyoctane, 1, 2-epoxynonan, 1,2-epoxydecane, 1,2-epoxyundecane, 1,2-epoxydodecane, styrene oxide, 1,2-epoxycyclopentane, 1,2-epoxycyclohexane, (2,3-epoxypropyl) benzene, vinyloxirane, 3- Phenoxy-1,2-epoxypropane, 2,3-epoxymethyl ether, 2,3-epoxyethyl ether, 2,3-epoxyisopropyl ether, 2,3-epoxy-1-propanol, (3,4-epoxybutyl) stearate, 4,5 -Epoxypentyl acetate, 2,3-epoxy propane methacrylate, 2,3-epoxy propane acrylate, glycidyl butyrate, methyl glycidate, ethyl 2,3-epoxy butanoate, 4- (trimethylsilyl) butane-1,2-epoxide, 4- (triethylsilyl) butane -l, 2-epoxy, 3- (perfluoromethyl) propene oxide, 3- (PerfluoroethyDpropenoxid, 3- (Perfluorobutyl) propenoxid, 4- (2, 3-Epoxypropy) morpholin, 1- (Oxiran-2-ylmethyl) pyrrolidin-2-one, as well as their arbitrary mixtures with each other, can be used. Ethylene oxide, propylene oxide, butylene oxide, styrene oxide, vinyloxirane and any mixtures thereof with one another, in particular ethylene oxide, propylene oxide, and mixtures of ethylene oxide and propylene oxide are preferred.

The polyether alcohols according to the invention mostly have a functionality of 2 to 8, preferably 2 to 4 and in particular 2 to 3 and an equivalent weight of more than 500 g / mol. The starting substances used as higher-functional starting substances are, in particular, sugar alcohols, for example sorbitol, hexitol and sucrose, but mostly two- and / or three-functional alcohols or water, either as a single substance or as a mixture of at least 2 of the starting substances mentioned. Examples of bifunctional starter substances are ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butanediol-1, 4 and pentantanedio -1, 5. Examples of bifunctional start substances are trimethylolpropane, pentaerythritol and in particular glycerin. The StartSubsces can also be used in the form of alkoxylates, in particular those with a molecular weight M _w in the range from 62 to 15000 g / mol. These alkoxylates can be prepared in a separate process step, and catalysts other than multimetal cyanide compounds, for example alkali metal hydroxides, can also be used for their preparation. When using alkali metal hydroxides to produce the alkoxylates, it is necessary to remove the catalyst almost completely, since alkali metal hydroxides can deactivate the multimetal cyanide catalysts. The advantage of using alkoxylates as starter substances is that the reaction starts faster, the disadvantage is the introduction of an additional process step and, as stated, the time-consuming cleaning of the alkoxylate.

The polyether alcohols produced using the DMC catalysts according to the invention are preferably used for the production of polyurethanes, in particular polyurethane foams and in particular flexible polyurethane foams. The polyurethanes are produced by reacting the polyether alcohols with polyisocyanates in the presence of catalysts, blowing agents and, if appropriate, other customary auxiliaries and / or additives. The invention is illustrated by the following examples.

Example 1: Preparation of the multimetal cyanide compound

In a 2-1 reactor equipped with a inclined blade turbine, a dip tube for dosing, an electrode for measuring the pH value, a conductivity measuring cell and a scattered light probe, 1000 g aqueous hexacyanocobaltaic acid (cobalt content: 9 g / 1 Cobalt) and heated to 50 ° C with stirring. 587 g of aqueous zinc acetate dihydrate solution (zinc content: 2.6% by weight), which was also heated to 50 ° C., were then added within 45 minutes with stirring.

A solution of 20 g of a surface-active compound (Pluronic® PE.6200 from BASF Aktiengesellschaft) in 30 g of water was then added. The mixture was heated to 60 ° C. and further stirred at this temperature for 2 hours. Then 186.1 g of aqueous zinc acetate dihydrate solution (zinc content: 2.6% by weight) were metered in with stirring at 60 ° C. within 20 min. After a few minutes, the conductivity started to drop. The suspension was stirred at a temperature of 60 ° C. until the pH of the suspension had dropped from 4.0 to 2.9 and remained constant. The precipitate suspension thus obtained was filtered off and washed with about 600 ml of water. A white powder was obtained.

Example 2: Spray drying of the multimetal cyanide compound from water with air as the drying and atomizing medium

45 g of moist filter cake of the multimetal cyanide compound

Example 1 with a proportion of multimetal cyanide compound from

• 32.2% by weight. were suspended in 185 g of water. The solids content of the suspension thus obtained was 7% by weight. The

Suspension was sprayed into a hot air stream with a two-fluid nozzle in a laboratory spray tower. The diameter of the spray tower used was 0.3 m, the height 0.6 m. The inlet temperature of the drying air was 160 ° C, the throughput of the drying air was 15.5 m3 / h. The spray rate was adjusted such that an exit temperature of the drying air of 70 ^C C yielded. The two-fluid nozzle was operated at a pre-pressure of 2 bar and an air throughput of 3 mS / h. At the exit of the spray tower, the dry multimetal cyanide compound was separated from the drying air using a cyclone. Example 3: Spray drying of the multimetal cyanide compound from t-butanol using nitrogen as the drying and atomizing medium

45 g of moist filter cake of the multimetal cyanide compound from Example 1 with a proportion of multimetal cyanide compound of 32.2% by weight were suspended in 185 g of t-butanol. The solids content of the suspension thus obtained was 7% by weight. The suspension was sprayed into a hot nitrogen stream using a two-fluid nozzle in a laboratory spray tower. The diameter of the spray tower used was 0.3 m, the height 0.6 m. The inlet temperature of the drying medium nitrogen was 160 ° C, the throughput of the drying medium was 15.5 m3 / h. The spray rate was set in such a way that an exit temperature of the drying medium of 70 ° C. resulted. The two-fluid nozzle was operated at a pre-pressure of 2 bar and a nitrogen throughput of 3 m3 / h. A Exit of the spray tower, the dry multimetal cyanide compound was separated from the drying medium with a cyclone.

Determination of the catalytic activity of the multimetal cyanide compound

In a 250 ml stirred autoclave, 128 g of a polypropylene glycol with a molecular weight M _w of 400 g / mol, hereinafter called PPG 400, were added in a variable amount of DMC catalyst from the preceding examples and 2 hours at 100 ° C. evacuated at 3 mbar. 72 g of propylene oxide were then metered in at 130.degree. After the rise in temperature and pressure, the maxima were recorded and recorded as the light-off time and at the same time evaluation for the activity. After the propylene oxide had completely reacted, as can be seen from the drop in pressure to a constant level, the resulting polypropylene glycol was at 100 ° C. after degassing. drained from the autoclave at 10 mbar and inertization with nitrogen.

The results of the catalytic activity of the multimetal cyanide compounds, their amounts used and the properties of the resulting polyether alcohols are summarized in Table 1. Table 1

Drying and DMC use of hydroxyl viscosity

Catalyst suspension set quantity spring time number 25 ° C

atomization

(ppm) (min) medium (%) (mgKOH / g) mPa s

Catalyst 1 water air 100 10. 100 178 101

Catalyst 1 water air 150 4 100 179 102

Catalyst 1-BuOH nitrogen 100 13 98 180 95

Catalyst 1 t-BuOH nitrogen 150 5 100 179 103

Claims

claims 1. A method for producing multimetal cyanide compounds comprising the steps a) reacting one of the aqueous solution of metal salt with the aqueous solution of a cyanometalate compound, b) spray drying the suspended multimetal cyanide compounds obtained in step a). 2. The method according to claim 1, characterized in that between steps a) and b) the multimetal cyanide compound produced in step a) is separated from the precipitation suspension. 3. The method according to claim 1, characterized in that the spray drying of the multimetal cyanide compound obtained in step a) is carried out from aqueous solution. 4. The method according to claim 1, characterized in that air, nitrogen or argon is used as the drying medium. 5. The method according to claim 1, characterized in that air is used as the drying medium. 6. The method according to claim 1, characterized in that the inlet temperature of the drying gas during spray drying is between 120 ° C and 350 ° C. 7. The method according to claim 1, characterized in that the multimetal cyanide compound general formula (I) M ^l _a [M (CN) _b (A) _c ] _d -fM ^l _g X _n -h (H ₂ 0) eL-kP (I), in which M ^{1 is} a metal ion selected from the group containing Zn ²⁺ , Fe ⁺ , Co ^{3 +} , Ni ²⁺ , Mn ²⁺ , Co ²⁺ , Sn ²⁺ , Sn ⁴ X Pb ^{2 +} , Mo ⁴⁺ , Mo ⁶⁺ , Al ^{3 +} , V ⁴⁺ , V ⁵⁺ , Sr ²⁺ , W ⁴ XW ⁶⁺ , Cr ²⁺ , Cr ³⁺ , Cd ⁺ , Cu ^{2 +} , La ³⁺ , M ^{2 is} a metal ion selected from the group comprising Fe ²⁺ , Fe +, Co ⁺ , Co ³⁺ , Mh +, Mn ³⁺ , Ni ⁺ V +, V ⁵ +, Cr +, ^• Cr ³⁺ , Rh ³⁺ , Ru ²⁺ , Ir ³⁺ , mean and M ¹ and M ^{2 are} different, A is an anion selected from the group consisting of halide, hydroxide, sulfate, carbonate, cyanide, thiocyanate, isocyanate, cyanate, carboxylate, oxalate or nitrate, X is an anion selected from the group consisting of halide, hydroxide, sulfate, carbonate, cyanide, thiocyanate, isocyanate, cyanate, carboxylate, oxalate, nitrate or nitrite (N0 ₂ ^~ ), and the uncharged species CO, H ₂ 0 and NO . L is a water-miscible ligand selected from the group consisting of alcohols aldehydes, ketones, ethers, polyethers, esters, polyesters, polycarbonates, ureas, amides, nitriles, and sulfides or mixtures thereof, P is an organic additive selected from the group consisting of 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 , Polyalkyl acrylates, polyalkyl methacrylates, polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl acetate, polyvinyl alcohol, poly-N-vinyl pyrrolidone, poly (N-vinyl pyrrolidone-co-acrylic acid), polyvinyl methyl ketone, poly (4-vinylphenol), poly (acrylic acid-co-styrene ), Oxazoline polymers, polyalkyleneimines, maleic acid and maleic anhydride copoly er, hydroxyethyl cellulose, polyacetates, ionic surfaces and surface-active compounds, bile acid or its salts, esters or amides, carboxylic acid esters of polyhydric alcohols and glycosides such as a, b, d, q and n are integer or fractional numbers greater than zero, c, f, e, h and k are integer or fractional numbers greater than zero, in which a, b, c, and d, and q and n are selected so that electroneutrality is ensured. 8. Multimetal cyanide compound, producible according to one of claims 1 to 6. 9. Use of the multimetal cyanide compound according to claim as a catalyst for the polymerization of alkylene oxides. 10. A process for the preparation of polyether alcohols by catalytic polymerization of alkylene oxides, characterized in that multimetal cyanide compounds according to claim 8 are used as catalysts.