MXPA01008132A - Double metal cyanide catalysts for producing polyether polyols - Google Patents

Abstract

The invention relates to novel double metal cyanide (DMC) catalysts for producing polyether polyols by polyaddition of alkylene oxides to starter compounds with active hydrogen atoms. The catalyst contains a) double metal cyanide compounds, b) organic complex ligands which are different from c) and c) ionic surface- or interface-active compounds. The inventive catalysts show considerably increased activity in the production of polyether polyols.

Description

Polyetherolines Description of the Invention The invention relates to novel catalysts of bimetal cyanide (DMC) for the production of polyether polyols by alkylene oxides to initiator compounds having active hydrogen atoms. The bimetallic cyanide (DMC) catalysts for the polyaddition of alkylene oxides to initiator compounds having active hydrogen atoms are known (see, for example, US-A 3 404 109, US-A 3 829 505, US-A 3 941 849 and US-A 5 158 922). The use of these DMC catalysts for the production of polyether polyols causes, in particular, a reduction of the part of monofunctional polyethers with terminal double bonds, called monooles, in comparison with the conventional production of polyether polyols by means of alkaline catalysts, such as alkali hydroxides. The polyether polyols thus obtained can be processed into valuable polyurethanes (eg elastomers, foams, coatings). The catalysts of DMC are usually obtained by reacting an aqueous solution of a metal salt with the aqueous solution of a metal cyanide salt in the presence of an organic complex ligand, eg of an ether. In a typical catalyst preparation as an example, aqueous solutions of Ref: -131885 zinc chloride (in excess) and potassium hexacyanocobaltate and then dimethoxyethane (glime) is added to the suspension formed. After filtration and washing of the catalyst with aqueous glime solution, an active catalyst of the general formula is obtained (see, for example, EP-A 700 949).

Zn3 [Co (CN) 6] 2 • x ZnCl2 • and H20 • z Glime From JP-A 4 145 123, US-A 5 470 813, EP-A 700 949, EP-A 743 093, EP-A 761 708 and WO 97/40086 DMC catalysts are known that when using tert-butanol as an organic complex ligand (alone or in combination with a polyether (EP-A 700 949, EP-A 761 708, WO 97/40086)) further reduce the proportion of monofunctional polyethers with terminal double bonds in the production of polyether polyols. In addition to this, when using these DMC catalysts the induction time in the reaction of polyaddition of the alkylene oxides with corresponding initiator compounds is reduced and the activity of the catalyst is raised. It has been the object of the present invention to provide improved DMC catalysts for the polyaddition of alkylene oxides to corresponding initiator compounds which have a higher catalytic activity compared to the types of catalysts known hitherto. This leads to shortened alkoxylation times to improved profitability of the polyol ether production process.

Ideally, upon increasing activity the catalyst can then be used in such low concentrations (25 ppm or less) that the very expensive separation of the catalyst from the product is no longer necessary and the product can be used directly for the manufacture of the polyurethane. Surprisingly it has now been found that DMC catalysts containing an ionic surfactant compound on surfaces or interfaces as a complex ligand possess a very high activity in the production of polyether polyols. It is therefore the object of the present invention a bimetallic cyanide catalyst (DMC) containing a) one or more bimetallic cyanide compounds, preferably one, b) one or more, preferably one, organic complex ligands other than c), and c) ) one or several, preferably one, ionic surfactant compounds on surfaces or interfaces. The catalyst according to the invention can optionally contain d) water, preferably 1 to 10% by weight and / or e) one or more water-soluble metal salts, preferably from 5 to 25% by weight, of formula (I) M (X) n of the preparation of the bimetal cyanide compounds a). In the formula (I) M is selected from the metals Zn (II), Fe (II), Ni (II), Mn (II), Co (II), Sn (II), Pb (II), Fe (III) ), Mo (IV), Mo (VI), Al (III), V (V), V (IV), Sr (II), W (IV), W (VI), Cu (II) and Cr (III) ).

Zn (II), Fe (II), Co (II) and Ni (II) are especially preferred. The anions X are the same or different, preferably identical, preferably selected from the group of halides, hydroxides, sulfates, carbonates, cyanates, thiocyanates, isocyanates, isothiocyanates, carboxylates, oxalates or nitrates. The value of n is 1, 2 or 3. The bimetallic cyanide compounds a) contained in the catalysts according to the invention are the reaction products of water-soluble metal salts and water-soluble metal cyanide salts. For the preparation of bimetallic cyanide compounds a) suitable water-soluble metal salts preferably have the general formula (I) M (X) n wherein M is selected from the metals Zn (II), Fe (II), Ni (II) ), Mn (II), Co (II), Sn (II), Pb (II), Fe (III), Mo (IV), Mo (VI), Al (III), V (V), V (IV) ), Sr (II), W (IV), W (VI), Cu (II) and Cr (III). Zn (II), Fe (II), Co (II) and Ni (II) are especially preferred. The anions X are the same or different, preferably the same, and are preferably selected from the group of halides, hydroxides, sulfates, carbonates, cyanates, thiocyanates, isocyanates, isothiocyanates, carboxylates, oxalates or nitrates. The value of n is 1, 2 or 3. Examples of suitable water-soluble metal salts are zinc chloride, zinc bromide, zinc acetate, zinc acetylacetonate, zinc benzoate, zinc nitrate, iron (II) sulfate, iron (II) bromide, iron (II) chloride, cobalt (II) chloride, cobalt (II) thiocyanate, nickel (II) chloride and nickel (II) nitrate. It is also possible to use mixtures of different water-soluble metal salts. For the preparation of bimetallic cyanide compounds a) suitable water-soluble metal cyanide salts preferably have the general formula (II) (Y) aM '(CN) b (A) c, in which M' is selected from the Fe metals (II), Fe (III), Co (II), Co (III), Cr (II), Cr (III), Mn (II), Mn (III), Ir (III), Ni (II), Rh (III), Ru (II), V (IV) and V (V). M 'is particularly preferably selected from the metals Co (II), Co (III), Fe (II), Fe (III), Cr (III), Ir (III) and Ni (II). The water-soluble metal cyanide salt may contain one or more of these metals. The Y cations are the same or different, preferably the same, and are selected from the group comprising the alkali metal ions and the alkaline earth metal ions. The anions A are the same or different, preferably the same, and are preferably selected from the group of halides, hydroxides, sulfates, carbonates, cyanates, thiocyanates, isocyanates, isothiocyanates, carboxylates, oxalates or nitrates. Both a and b and c are integers, the values of a, b and c being chosen so as to result in the electroneutrality of the metal cyanide salt; a is preferably 1, 2, 3 or 4; b is preferably 4, 5 or 6; c preferably has the value 0. Examples of suitable water-soluble metal cyanide salts are potassium hexanocyanocobaltate (III), potassium hexacyanoferrate (II), potassium hexacyanoferrate (III), calcium hexanocyanocobaltate (III) and hexanocyanocobaltate (III) of lithium. Preferred bimetallic cyanide compounds a) contained in the catalysts according to the invention are the compounds of general formula (III) MX [M'X, (CN) and] 2, wherein M is defined as in formula (I) and M 'as in formula (II), and x, x', y and z are integers and are chosen so as to result in the electroneutrality of the bimetallic cyanide compound. Preferably they are x = 3, x '= 1, y = 6 and z = 2, M = Zn (II), Fe (II), Co (II) or Ni (II) and M' = Co (III), Fe ( III), Cr (III) or Ir (III). Examples of suitable bimetal cyanide compounds are a) zinc hexanocyanocobaltate (III), zinc hexacyanidate (III), zinc hexacyanoferrate (III) and cobalt (II) hexanocyanocobaltate (III). Other examples of suitable bimetal cyanide compounds are listed, for example, in US Pat. No. 5,158,922. Zinc hexanocyanocobaltate (III) is particularly preferred. The organic complex ligands b) contained in the DMC catalysts according to the invention are in principle known and are described in detail in the state of the art (for example in US-A 5 158 922, US-A 3 404 109, US-A 3 829 505, US-A 3 941 849, EP-A 700 949, EP-A 761 708, JP-A 4 145 123, US-A 5 470 813, EP- A 743 093 and WO 97/40086). Preferred organic complex ligands are water-soluble organic compounds with heteroatoms such as oxygen, nitrogen, phosphorus or sulfur, which can form complexes with the bimetallic cyanide compound a). Suitable organic complex ligands are, for example, alcohols, aldehydes, ketones, ethers, esters, amides, ureas, nitriles, sulfides and mixtures thereof. Preferred organic complex ligands are water-soluble aliphatic alcohols such as ethanol, isopropanol, n-butanol, iso-butanol, sec-butanol and tert-butanol. Especially preferred is tert-butanol. The organic complex ligand is added either during the preparation of the catalyst or immediately after the precipitation of the bimetal cyanide compound a). Usually, the organic complex ligand is used in excess. The DMC catalysts according to the invention contain the bimetallic cyanide compounds a) in amounts of 20 to 90% by weight, preferably 25 to 80% by weight, based on the amount of the catalyst prepared, and the organic complex ligands b ) in amounts of 0.5 to 30, preferably 1 to 25% by weight, based on the amount of catalyst prepared. The DMC catalysts according to the invention usually contain from 1 to 80% by weight, preferably from 1 to 40% by weight, based on the amount of the catalyst prepared, of surfactant compounds on surfaces or interfaces. The structural characteristic of ionic surfactant compounds on surfaces or interfaces c) suitable for the preparation of the catalysts according to the invention is their amphiphilic molecular structure, ie they contain at least one hydrophilic ionic group (or a part of the hydrophilic ionic molecule ) and at least one hydrophobic group (or a part of the hydrophobic molecule). Examples of such surfactant ionic compounds on surfaces or interfaces are in the group of surfactants, soaps, emulsifiers, detergents and dispersants. The hydrophilic ionic groups can be anionic, cationic or dipolar ion (amphoteric). Examples of anionic groups are carboxylate, sulfonate, sulfate, thiosulfate, phosphonate, phosphinate, phosphate or dithiophosphate groups. Examples of cationic groups are ammonium, phosphonium or sulfonium groups. Examples of dipolar ion groups are betaine, sulfobetaine or aminoxide groups. The hydrophilic groups are preferably C2-C50 hydrocarbon radicals, such as aryl, aralkyl and alkyl radicals. But fluoroalkyl, silaalkyl, thiaalkyl or oxalkyl groups are also suitable.

Examples of suitable classes of compounds are hydrophilic anionic groups, carboxylates such as alkylcarboxylates (soaps), ether carboxylates (carboxymethylated ethoxylates), polycarboxylates such as malonates and succinates, salts of bile acid, eg bile acid amides with sulfoalkyl and carboxyalkyl radicals in the salt form, amino acid derivatives such as sarcosides (alkyl sarcosinates) sulfonamidocarboxylates, sulphates such as alkyl sulfates, ether sulfates, eg fatty alcohol ether sulfates, arylether sulfates or amidoethersulfates, sulphated carboxylates, sulfated carboxylic acid glycerides, sulfated carboxylic acid esters, sulfated carboxamides, sulfonates, eg alkyl-, aryl - and alkylarylsulfonates, sulphonated carboxylates, sulfonated carboxylic acid esters, sulfonated carboxylic acid amides, carboxylestersulfonates such as esters of α-sulfo fatty acid, carboxyamido sulfonates, sulfosuccinic acid esters, ether sulfonates, thiosulfates, phosphates, eg alkylphosphates or glycerin phosphates, phosphonates , phosphinates and dithiophosphates. Examples of suitable classes of compounds with hydrophilic cationic groups are primary, secondary, tertiary and quaternary ammonium salts with alkyl, aryl and aralkyl moieties, alkoxylated ammonium salts, quaternary ammonium esters, benzylammonium salts, alkanolammonium salts, pyridinium salts , imidazolinium salts, oxazolinium salts, thiazolinium salts, amine oxide salts, sulfonium salts, quinolinium salts, isoquinoline salts and tropylium salts. Examples of suitable classes of compounds are dipolar (amphoteric) ionyl groups, hydrophilic amine oxides, imidazolinium derivatives such as imidazolinium carboxylates, betaines, for example alkyl and amidopropyl betaines, sulfobetaines, amino acids and phospholipids, eg phosphatidylcholine. (lecithin).

Of course, the surfactant ionic compounds on surfaces or interfaces may also contain several hydrophilic groups or parts of the molecule (anionic and / or cationic and / or dipolar ion). The surfactant ionic compounds on surfaces or interfaces c) may be used alone or in combination. Surface-active ionic compounds or interfaces c) suitable for the preparation of the catalysts according to the invention are generally well known and, for example, are described in detail in "Ullmann's Encyclopedia of Industrial Chemistry", 5th edition, vol. A25, pages 747-817, VCH, Weinheim, 1994, "Kirk-Othmer, Encyclopedia of Chemical Technology" 4th edition, vol. 23, pgs. 477-541, John Wiley & Sons, New York, 1997, "Tensid-Taschenbuch", 2nd edition, H. Stache (Ed.), Carl Hanser Verlag, Munich, 1982, "Surfactant Science Series", vol. 1-74, M.J. Schick (Consulting Editor), Marcel Decker, New York, 1967-1998, "Methods in Enzymology", vol. 182, M.P. Deutscher (Ed.), Pgs. 239-253, Academic Press, San Diego, 1990. The analysis of the catalyst composition is usually performed by elemental analysis, thermogravimetry or extractive separation of the surfactant component part on surfaces or interfaces and subsequent gravimetric determination. The catalysts according to the invention can be crystalline, partially crystalline or amorphous. The analysis of the crystallinity is usually carried out by powder X-ray diffractometry. Catalysts according to the invention containing a) tin hexacyanocobaltate (III), b) tert-butanol and c) an ionic surface-active compound on surfaces or interfaces are preferred. The preparation of the DMC catalysts according to the invention is usually carried out in aqueous solution by reacting metal salts, in particular of formula (I), with metal cyanide salts, in particular of formula (II), β). organic complex b) that are not surfactant ionic compounds on surfaces or interfaces and and y) surfactant ionic compounds on surfaces or interfaces c). In this connection, the aqueous solutions of the metal salt (eg zinc chloride) are preferably reacted first., used in stoichiometric excess (at least 50 mol% based on the metal cyanide salt)) and the metal cyanide salt (eg potassium hexacyanocobaltate) in the presence of the organic complex ligand b) (e.g. tert-butanol), forming a suspension containing the bimetallic cyanide compound a) (eg zinc hexacyanocobaltate), water d), metal salt e) in excess, and the organic complex ligand b). The organic complex ligand b) may in this case be present in the aqueous solution of the metal salt and / or the metal cyanide salt, or may be added directly to the suspension obtained after the precipitation of the bimetal cyanide compound a). It has turned out to be advantageous to mix the aqueous solutions and the organic complex ligands b) under strong stirring. The suspension formed is usually treated in the following with one or more ionic surfactant compounds on surfaces or interfaces c). Component c) is preferably used in this connection in a mixture with water and organic complex ligand b). The isolation of the catalyst from the suspension is then carried out by known techniques, such as centrifugation or filtration. In a preferred embodiment, the isolated catalyst is then washed with an aqueous solution of the organic complex ligand b) (eg by resuspension and subsequent re-isolation by filtration or centrifugation). In this way, for example, water-soluble by-products, such as potassium chloride, can be removed from the catalyst according to the invention.

Preferably the amount of organic complex ligand b) in the aqueous wash solution is between 40 and 80% by weight, based on the total solution. In addition, it is advantageous to add to the aqueous washing solution a small amount of the ionic surfactant (s) on surfaces or interfaces c) used as component y), preferably 0.5 to 5% by weight, based on the total solution. In addition, it is advantageous to wash the catalyst more than once. For this, the first washing process can be repeated, for example. However, it is preferable to use non-aqueous solutions for the other washing processes, eg a mixture of the organic complex ligand and the ionic surfactant (s) on surfaces or interfaces c) used as component?). Subsequently, the washed catalyst, if appropriate after spraying, is dried at temperatures of generally 20-100 ° C and at pressures of generally 0.1 mbar at normal pressure (1013 mbar). Another object of the present invention is the use of the DMC catalysts according to the invention in a process for the production of polyether polyol ethers of alkylene oxides to initiator compounds having active hydrogen atoms. As the alkylene oxides, ethylene oxide, propylene oxide, butylene oxide and mixtures thereof are preferably used. The synthesis of the polyether chains by alkoxylation can, for example, be carried out with only one monomeric epoxide or else statistically or in block with 2 or 3 different monomeric epoxides. More details can be found in "Ullmanns Encyclopaedia der industriellen Chemie", vol. A21, 1992, p. 670 and next. As starter compounds having active hydrogen atoms, molecular weight compounds (number media) of 18 to 2,000 and 1 to 8 hydroxyl groups are preferably used. By way of example, mention may be made of: ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,4-butanediol, hexamethylene glycol, bisphenol A, trimethylolpropane, glycerin, pentaerythritol, sorbitol, cane sugar, digested starch or water. It is advantageous to use those initiator compounds having active hydrogen atoms obtained, for example, by conventional alkaline catalysis of the abovementioned low molecular weight initiators and to synthesize oligomeric alkoxylation products of molecular weights (number means) of 200 to 2,000. The polyaddition catalyzed by catalysts according to the invention of alkylene oxides to initiator compounds having active hydrogen atoms is generally carried out at temperatures of 20 to 200 ° C, preferably in the range of 40 to 180 ° C, with particular preference to temperatures from 50 to 150 ° C. The reaction can be carried out at total pressures of 0.0001 to 20 bar. The polyaddition can be carried out in a substance or in an inert organic solvent, such as toluene and / or THF. The amount of solvent is usually between 10 and 30% by weight, based on the amount of the polyether polyol to be produced. The catalyst concentration is chosen so that under the given reaction conditions a good control of the polyaddition is possible. The catalyst concentration is generally in the range of 0.0005% by weight to 1% by weight, preferably in the range of 0.001% by weight to 0.1% by weight, particularly preferably in the range of 0.001% by weight. 0.0025% by weight, based on the amount of the polyether polyol to be produced. The molecular weights (number means) of the polyether polyols produced according to the invention are in the range of 500 to 100,000 g / mol, preferably in the range of 1,000 to 50,000 g / mol, particularly preferably in the range of 2,000 to 20,000. g / mol The polyaddition can be carried out continuously or batchwise, for example in a discontinuous or semi-batch process. The catalysts according to the invention can be used, due to their clear greater activity, in very low concentrations (25 ppm and less, referred to the amount of the polyether polyol to be produced). If the polyether polyols produced in the presence of catalysts according to the invention are used for the production of polyurethanes (Kunststoffhandbuch, Vol 7, Polyurethane, 3rd edition, 1993, pp. 25-32 and 57-67), the removal of the catalyst can be suppressed. of the polyether without inconveniently affecting the product quality of the obtained polyurethane.

Ejgmplps Preparation of the catalyst Ta c-Hi ip A Preparation of a DMC catalyst with sodium salt of cholic acid (Catalyst A) To a solution of 2 g (6 mmol) of potassium hexacyanocobaltate in 35 ml of distilled water was added with vigorous stirring (24,000 rpm) a solution of 6.2 g (45.75 mmol) of zinc chloride in 10 ml of distilled water. Immediately afterwards a mixture of 25 g of tert-butanol and 25 g of distilled water was added to the formed suspension and then stirred vigorously (24,000 rpm) for 10 min. Then a mixture of 0.5 g of colic acid sodium salt was added (Fluka Chemie AG, CH-9471 Buchs), 0.5 g of tert-butanol and 50 g of distilled water and stirred for 3 min (1,000 rpm). The solid matter was isolated by filtration, then stirred (10,000 rpm) for 10 min with a mixture of 35 g of tert-butanol, 15 g of distilled water and 0.5 g of sodium salt of cholic acid and filtered again. Finally, it was stirred (10,000 rpm) again for 10 min with a mixture of 50 g of tert-butanol and 0.25 g of sodium salt of cholic acid. After filtering, the catalyst was dried at 50 ° C and under normal pressure to constant weight. Dry pulverulent catalyst yield: 2.1 g Elemental analysis, thermogravimetric analysis and extraction: Cobalt = 12.6% by weight, Zinc = 27.3% by weight, tert-Butanol = 10.9% by weight, Cholic acid sodium salt = 4.3% by weight. p oTTipi) B Preparation of a DMC catalyst with lacrythine (Catalyst B) The procedure was as in Example A, but La-lecithin (egg yolk, Fluka Chemie AG, CH-9471 Buchs) was used instead of sodium salt of cholic acid. Dry pulverulent catalyst yield: 2.0 g Elemental analysis, thermogravimetric analysis and extraction: Cobalt = 13.7% by weight, Zinc = 25.6% by weight, tert-Butanol = 7.5% by weight, La-lecithin = 12.0% by weight. Example C Preparation of a DMC catalyst with sodium salt of N-lauroyl sarcosine (Catalyst C) The procedure was as in Example A, but the sodium salt of N-lauroyl sarcosine (Fluka Chemie AG, CH-9471 Buchs) was used instead of salt Sodium of cholic acid. Dry pulverulent catalyst yield: 1.95 g Elemental analysis, thermogravimetric analysis and extraction: Cobalt = 13.2% by weight, Zinc = 28.6% by weight, tert-Butanol = 9.5% by weight, Sodium salt of N-lauroyl sarcosine = 6.2% by weight. Tüjotnpifr r »(tüj <» tnpi.o comparative) Preparation of a DMC catalyst using tert-butanol without surfactant compound on surfaces or interfaces (Catalyst D, synthesis according to JP-A 4145123) To a solution of 4 g ( 12 mmol) of potassium hexacyanocobaltate in 75 ml of distilled water was added with vigorous stirring (24,000 rpm) a solution of 10 g (73.3 mmol) of zinc chloride in 15 ml of distilled water. Immediately afterwards a mixture of 50 g of tert-butanol and 50 g of distilled water was added to the formed suspension and then stirred vigorously (24,000 rpm) for 10 min. The solid matter was isolated by filtration, then stirred (10,000 rpm) for 10 min with 125 g of a mixture of tert-butanol and distilled water (weight ratio 70/30) and filtered again. Finally it was stirred again (10,000 rpm) for 10 min with 125 g of tert-butanol. After filtering, the catalyst was dried at 50 ° C and under normal pressure to constant weight. Dry pulverulent catalyst yield: 3.08 g Elemental analysis: Cobalt = 13.6% by weight, Zinc = 27.4% by weight, tert-butanol = 14.2% by weight. Polyol ether production General implementation In a 500 ml pressure reactor, 50 g of polypropylene glycol as the initiator (number average molecular weight 1000 g / mol) and 3 to 5 mg of catalyst (15 to 25 ppm) were placed under protective gas (argon). , referring to the amount of the polyether polyol to be produced) and stirring was heated to 105 ° C. Thereafter, propylene oxide (approximately 5 g) was dosed at a time until the total pressure rose to 2.5 bar. Only more propylene oxide is dosed again when an accelerated pressure drop is observed in the reactor. This accelerated pressure drop indicates that the catalyst is activated. The rest of the propylene oxide (145 g) is then metered in continuously at a constant total pressure of 2., 5 bar. After the complete dosing of the propylene oxide and a further 2 hours of reaction time at 105 ° C, the volatile fractions were distilled off at 90 ° C (1 mbar) and then cooled to room temperature. The polyether polyols obtained were characterized by determining the OH indices, the content of double bonds and the viscosities. The development of the reaction was followed by transformation-time curves (consumption of propylene oxide [g] versus reaction time [min]). The induction time was determined by the tangent cut-off point at the steepest point of the transformation-time curve with the prolongation of the baseline curve. The propoxylation times determining the activity of the catalyst correspond to the time interval between the activation of the catalyst (end of the induction period) and the end of the dosage of the propylene oxide. The total reaction time is the sum of the induction time and the propoxylation time. g om ip i Polyol ether production with catalyst A (15 ppm) Induction time: 230 min Propoxylation time: 95 min Total reaction time: 325 min Polyol ether: OH number (mg KOH / g): 28.9 Content of double bonds (mmol / kg): 4 Viscosity at 25 ° C (mPas): 982 Without the separation of the catalyst the metal content in the polyol amounted to : Zn = 4 ppm, Co = 2 ppm. K ompi 2 Polyol ether production with catalyst B (25 ppm) Induction time: 125 min Propoxylation time: 140 min Total reaction time: 265 min Polyol ether: OH number (mg KOH / g): 29.5 Content of double bonds (mmol / kg): 6 Viscosity at 25 ° C (mPas): 921 Kjgm ip 3 Production of polyether ether with catalyst C (25 ppm) Induction time: 350 min Propoxylation time: 40 min Total reaction time: 390 min Polyether ether: OH number (mg KOH / g): 30.4 Content of double bonds (mmol / kg): 6 Viscosity at 25 ° C (mPas): 842 rcjyp1? 4 (Comparative) Catalyst D (15 ppm) showed no activity under the conditions described above even after 14 h of induction time. Using 50 ppm of catalyst D the induction time amounted to approx. 9 h. The propoxylation time amounted to more than 12 hours, with deactivation of the catalyst taking place during the course of the reaction. Examples 1-3 indicate that the novel DMC catalysts according to the invention can be used, due to their clearly high activity in the production of polyether polyols, in such low concentrations that the separation of the catalyst from the polyol can be suppressed.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (12)

ReivánrH ^ cioneS Having described the invention as above, the content of the following claims is claimed as property

1. Bimetal cyanide catalyst (DMC) containing a) one or more bimetallic cyanide compounds, b) one or more organic complex ligands other than c), and c) one or more surfactant ionic compounds on surfaces or interfaces.

2. DMC catalyst according to claim 1 further containing d) water and / or e) water-soluble metal salt.

3. DMC catalyst according to claim 1 or 2, wherein the bimetallic cyanide compound is zinc hexacyanocobaltate (III).

4. DMC catalyst according to one of claims 1 to 3, wherein the organic complex ligand is tert-butanol.

5. DMC catalyst according to one of claims 1 to 4 containing from 1 to 80% by weight of one or more surfactant ionic compounds on surfaces or interfaces.

6. DMC catalyst according to one of claims 1 to 5, in which the surfactant ionic compound on surfaces or interfaces contains an anionic hydrophilic group.

7. DMC catalyst according to one of claims 1 to 5, in which the surfactant ionic compound on surfaces or interfaces contains a cationic hydrophilic group.

8. DMC catalyst according to one of claims 1 to 5, in which the surfactant compound on surfaces or interfaces contains a hydrophilic group of dipolar ion

9. Process for the preparation of a DMC catalyst, comprising the steps of i) reaction in aqueous solution of a) metal salts with metal cyanide salts, β) organic complex ligands that are not ionic surfactant compounds on surfaces or interfaces, and ) surfactant ionic compounds on surfaces or interfaces, ii) isolation, washing and drying of the catalyst obtained in step i).

10. Process for the production of polyether polyols by alkylene oxides to initiator compounds having active hydrogen atoms in the presence of one or more DMC catalysts according to one of claims 1 to 8.

11. Polyol ether producible according to the method according to claim 10.

12. Use of one or more DMC catalysts according to one of claims 1 to 8 for the production of polyether polyols by alkylene oxides to initiator compounds having active hydrogen atoms.