DE19920937A1 - Double metal cyanide catalyst used in production of polyether polyol, e.g. for polyurethane manufacture, contains ionic surfactant and different organic complex ligand - Google Patents

Abstract

Double metal cyanide (DMC) catalyst contains: (a) double metal cyanide compound(s); (b) organic complex ligand(s), other than (c), and (c) ionic surfactant(s). Independent claims are also included for: (1) A process for producing polyether polyols by polyaddition of alkylene oxides to starter compounds containing active hydrogen atoms in the presence of the catalyst(s). (2) Polyether polyols produced by this process. (3) The production of the catalyst.

Description

The invention relates to new double metal cyanide (DMC) catalysts for the Her position of polyether polyols by polyaddition of alkylene oxides to active Starter compounds containing hydrogen atoms.

Double metal cyanide (DMC) catalysts for the polyaddition of alkylene oxides to starter compounds having active hydrogen atoms are known (see, for example, US Pat. Nos. 3,440,109, 3,829,505, 3,941,849 and 5,158) 922). The use of these DMC catalysts for the production of polyether polyols in particular brings about a reduction in the proportion of monofunctional polyethers with terminal double bonds, so-called monools, compared to the conventional production of polyether polyols using alkali catalysts, such as alkali metal hydroxides. The polyether polyols thus obtained can be processed to high-quality poly urethanes (e.g. elastomers, foams, coatings). DMC catalysts are usually obtained by mixing an aqueous solution of a metal salt with the aqueous solution of a metal cyanide salt in the presence of an organic complex ligand, e.g. B. an ether. In a typical catalyst preparation, for example, aqueous solutions of zinc chloride (in excess) and potassium hexacyanocobaltate are mixed and then dimethoxy ethane (glyme) is added to the suspension formed. After filtration and washing of the catalyst with aqueous glyme solution, an active catalyst of the general formula

Zn ₃ [Co (CN) ₆ ] ₂ .x ZnCl ₂ .yH ₂ Oz Glyme

obtained (see e.g. EP-A 700 949).  

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, which by 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)) the proportion of monofunk tional polyethers with terminal double bonds in the production of Reduce polyether polyols further. In addition, by using this DMC catalysts the induction time in the polyaddition reaction of the alkylene oxides with appropriate starter compounds and reduced catalyst activity elevated.

The object of the present invention was to further improve DMC catalysts for the polyaddition of alkylene oxides to corresponding starter compounds To make available a with regard to the previously known catalyst types have increased catalyst activity. This is done by shortening the Alkoxylation times for an improved economy of the manufacturing process of polyether polyols. Ideally, the increased activity of the catalyst then used in such low concentrations (25 ppm or less) that the very complex separation of the catalyst from the product is no longer necessary is, and the product can be used directly for polyurethane production.

Surprisingly, it has now been found that DMC catalysts that are ionic contain surface or surface-active compound as complex ligands, have greatly increased activity in the production of polyether polyol.

The present invention therefore relates to a double metal cyanide (DMC) catalyst comprising

• a) one or more, preferably a double metal cyanide compound,
• b) one or more, preferably one, organic, different from c) Complex ligands, and  
• c) one or more, preferably an ionic surface or boundary surface active connection.

In the catalyst according to the invention, optionally d) water, preferably 1 to 10% by weight and / or e) one or more water-soluble metal salts, preferably 5 to 25% by weight, of the formula (I) M (X) _n the preparation of the double metal cyanide compounds a) may be included. In 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 particularly preferred. The anions X are the same or different, preferably the same, and preferably selected from the group of halides, hydroxides, sulfates, carbonates, cyanates, thiocyanates, isocyanates, isothiocyanates, carboxylates, oxalates or nitrates. The value for n is 1, 2, or 3.

The double metal cyanide ver contained in the catalysts of the invention Bonds a) are the reaction products of water-soluble metal salts and water soluble metal cyanide salts.

Water-soluble metal salts suitable for the preparation of double metal cyanide compounds a) preferably have the general formula (I) M (X) _n , where 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 particularly 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 for 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. Mixtures of different water-soluble Me tall salts are used.

Water-soluble metal cyanide salts suitable for the preparation of double metal cyanide compounds a) preferably have the general formula (II) (Y) _a M '(CN) _b (A) _c , where M' is selected from the metals Fe (II), Fe (III ), Co (II), Co (III), Cr (II), Cr (III), Mn (II), Mn (III), Ir (III), Ni (II), Rh (III), Ru (II ), V (IV) and V (V). 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 can contain one or more of these metals. The cations Y are the same or different, preferably the same, and are selected from the group consisting of alkali metal ions and alkaline earth metal ions. The anions A are the same or different, preferably the same, and are 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 for a, b and c being chosen so that the electroneutrality of the metal cyanide salt is given; 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 hexacyanocobaltate (III), potassium hexacyanoferrate (II), potassium hexacyanoferrate (III), calcium hexacyanocobaltate (III) and lithium hexacyanocobaltate (III).

Preferred double metal cyanide compounds a) which are contained in the catalysts according to the invention are compounds of the general formula (III)

M _x [M ' _x , (CN) _y ] _z

wherein M as in formula (I) and
M 'is as defined in formula (II), and
x, x ', y and z are integers and are chosen such that the electron neutrality of the double metal cyanide compound is given.

Preferably
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 double metal cyanide compounds a) are zinc hexacyanocobal tat (III), zinc hexacyanoiridate (III), zinc hexacyanoferrate (III) and cobalt (II) hexacyano cobaltate (III). Further examples of suitable double metal cyanide compounds are e.g. See for example US-A 5 158 922. Zinc hexa is particularly preferably used cyanocobaltate (III).

The organic com contained in the DMC catalysts of the invention plexigands b) are known in principle and be extensively in the prior art wrote (e.g. 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, stick substance, phosphorus or sulfur, which with the double metal cyanide compound a) com can form plexes. Suitable organic complex ligands are e.g. B. alcohols, Aldehydes, ketones, ethers, esters, amides, ureas, nitriles, sulfides and their Mi worked. Preferred organic complex ligands are water-soluble aliphatic Alcohols, such as ethanol, isopropanol, n-butanol, iso-butanol, sec-butanol and tert-Bu tanol. Tert-butanol is particularly preferred.

The organic complex ligand is generated either during the catalyst preparation added or immediately after the precipitation of the double metal cyanide compound a). The organic complex ligand is usually used in excess.  

The DMC catalysts according to the invention contain the double metal cyanide ver Bonds a) in amounts of 20 to 90 wt .-%, preferably 25 to 80 wt .-%, bezo on the amount of the finished catalyst, and the organic complex ligands b) in amounts of 0.5 to 30, preferably 1 to 25 wt .-%, based on the amount of finished catalyst. The DMC catalysts according to the invention usually contain Usually 1 to 80 wt .-%, preferably 1 to 40 wt .-%, based on the amount of finished catalyst, on ionic surface or surface-active compound c).

Structural feature of those used to produce the catalysts of the invention suitable ionic surface-active or surface-active compounds c) is yours amphiphilic molecular structure, d. H. they contain at least one hydrophilic ionic Group (or a hydrophilic ionic part of the molecule) and at least one hydrophobic group (or a hydrophobic part of the molecule). Examples of such Ionic surface or surface active compounds can be found in the Group of surfactants, soaps, emulsifiers, detergents and dispersants. The hydrophilic ionic groups can be anionic, cationic or hermaphrodite be ionic (amphoteric) in nature. Examples of anionic groups are carboxylate, Sulfonate, sulfate, thiosulfate, phosphonate, phosphinate, phosphate or dithio phosphate groups. Examples of cationic groups are ammonium, phosphonium or sulfonium groups. Examples of zwitterionic groups are betaine and sulfo betaine or amine oxide groups.

The hydrophobic groups are preferably C ₂ -C ₅₀ hydrocarbon residues such as aryl, aralkyl and alkyl residues. However, fluoroalkyl, silaalkyl, thiaalkyl or oxaalkyl groups are also suitable.

Examples of suitable classes of compounds with hydrophilic anionic groups are Carboxylates such as alkyl carboxylates (soaps), ether carboxylates (carboxymethylated Ethoxylates), polycarboxylates such as malonates and succinates, bile acid salts, e.g. B.  Bile acid amides with sulfoalkyl and carboxyalkyl residues in the salt form, amino acid derivatives such as sarcosides (alkanolysarcosinates), sulfonamidocarboxylates, sulfates such as alkyl sulfates, ether sulfates, e.g. B. fatty alcohol ether sulfates, aryl ether sulfates or Amido ether sulfates, sulfated carboxylates, sulfated carboxylic acid glycerides, sulfa tated carboxylic acid esters, sulfated carboxamides, sulfonates, e.g. B. alkyl, aryl and alkylarylsulfonates, sulfonated carboxylates, sulfonated carboxylic acid esters, sulfo nated carboxamides, carboxyl ester sulfonates such as α-sulfofatty acid esters, carb oxyamide sulfonates, sulfosuccinic acid esters, ether sulfonates, thiosulfates, phosphates, e.g. B. alkyl phosphates or glycerol phosphates, phosphonates, phosphinates and di thiophosphate.

Examples of suitable classes of compounds with hydrophilic cationic groups are primary, secondary, tertiary and quaternary ammonium salts with alkyl, aryl and Aralkyl radicals, alkoxylated ammonium salts, quaternary ammonium esters, benzyl ammonium salts, alkanolammonium salts, pyridinium salts, imidazolinium salts, Oxazolinium salts, thiazolinium salts, salts of amine oxides, sulfonium salts, Quinolinium salts, isoquinolinium salts and tropylium salts.

Examples of suitable classes of compounds with hydrophilic zwitterionic (ampho Ter) group are amine oxides, imidazolinium derivatives such as imidazolinium car boxylates, betaines, e.g. B. alkyl and amidopropyl betaines, sulfobetaines, aminocarbon acids and phospholipids, e.g. B. phosphatidylcholine (lecithin).

Of course, the ionic surface or surface active compounds also several hydrophilic (anionic and / or cationic and / or zwitterionic) Contain groups or parts of molecules.

The ionic surface-active or surface-active compounds c) can individually or in combination.  

The ionic surface-active or surface-active compounds suitable for the preparation of the catalysts according to the invention are generally well known and are known e.g. As 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", 4 ^th Edition, Vol. 23, pp. 477-541, John Wiley & Sons, New York, 1997, "Tensid-Taschenbuch", 2nd ed., H. Stache (ed.), Carl Hanser Verlag, Munich, 1982, "Surfactant Science Series" , Vol. 1-74, MJ Schick (Consulting Editor), Marcel Decker, New York, 1967-1998, "Methods in Enzymology", Vol. 182, MP Deutscher (Ed.), Pp. 239-253, Academic Press, San Diego, 1990.

The analysis of the catalyst composition is usually carried out using elements Tar analysis, thermogravimetry or extractive removal of the proportion of ionic Surface or interface active connection followed by gravimetri determination.

The catalysts of the invention can be crystalline, semi-crystalline or amorphous his. The crystallinity is usually analyzed using powder X-rays diffractometry.

Catalysts according to the invention are preferred

• a) zinc hexacyanocobaltate (III),
• b) tert-butanol and
• c) an ionic surface-active or surface-active compound.

The DMC catalysts according to the invention are usually produced in aqueous solution by reacting a) metal salts, in particular of the formula (I) with metal cyanide salts, in particular of the formula (II), β) organic complex ligands b) which do not contain any ionic surface-active or surface-active compounds are genes, and γ) ionic surface-active or surface-active compounds c).  

The aqueous solutions of the metal salt (e.g. Zinc chloride, used in a stoichiometric excess (at least 50 mol% based on the metal cyanide salt)) and the metal cyanide salt (e.g. potassium hexa cyanocobaltate) in the presence of the organic complex ligand b) (e.g. tert-buta nol) implemented, forming a suspension that the double metal cyanide Ver bond a) (e.g. zinc hexacyanocobaltate), water d), excess metal salt e), and contains the organic complex ligand b).

The organic complex ligand b) can be in the aqueous solution of the metal salt and / or the metal cyanide salt may be present, or it becomes the after Precipitation of the double metal cyanide compound a) suspension obtained immediately admitted. It has proven advantageous to use the aqueous solutions and the to mix organic complex ligands b) with vigorous stirring. The educated Suspension is usually followed by one or more ionic surface or surface active compound (s) c) treated. The compo nente c) is preferred in a mixture with water and organic Complex ligands b) used.

The catalyst is then isolated from the suspension by be known techniques such as centrifugation or filtration. In a preferred embodiment Rung variant, the isolated catalyst is then with an aqueous solution of the organic complex ligand b) washed (e.g. by resuspending and on subsequent re-isolation by filtration or centrifugation). In this way can, for example, water-soluble by-products, such as potassium chloride, from which it inventive catalyst are removed.

The amount of the organic complex ligand b) is preferably in the aqueous Washing solution between 40 and 80 wt .-%, based on the total solution. Next it is advantageous to add a small amount of the aqueous washing solution as a compo nente γ) used ionic surface or surface-active compound addition (s) c), preferably 0.5 to 5% by weight, based on the total solution.  

It is also advantageous to wash the catalyst more than once. For this can e.g. B. the first washing process can be repeated. However, it is preferred for to use further washing processes non-aqueous solutions, e.g. B. a mixture from organic complex ligands and the ioni used as component γ) surface-active or surface-active compound (s) c).

The washed catalyst is then, optionally after pulverization, at temperatures of generally 20 to 100 ° C and at pressures in general my 0.1 mbar to normal pressure (1013 mbar) dried.

Another object of the present invention is the use of the inventions DMC catalysts according to the invention in a process for producing poly ether polyols by polyaddition of alkylene oxides to active hydrogen atoms having starter connections.

Preferred alkylene oxides are ethylene oxide, propylene oxide, butylene oxide and their mixtures are used. The structure of the polyether chains by alkoxylie tion can z. B. can be carried out only with a monomeric epoxy or also statistically or in blocks with 2 or 3 different monomeric epoxides consequences. Further details are "Ullmann's Encyclopedia of Industrial Chemistry", Volume A21, 1992, p. 670f.

Starter compounds having active hydrogen atoms are preferred Compounds with (number average) molecular weights from 18 to 2,000 and 1 to 8 hydroxyl groups used. Examples include: ethylene glycol, Di ethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,4-butanediol, hexamethylene glycol, bisphenol A, trimethylolpropane, glycerin, pentaerythritol, sorbitol, cane sugar, degraded starch or water.  

Advantageously, such starters having active hydrogen atoms bindings used, the z. B. by conventional alkali analysis from the previously ge called low molecular weight starters and oligomeric alkoxylie Representation products with (number average) molecular weights from 200 to 2000.

The polyaddition catalyzed by the catalysts of the invention Alkylene oxides are carried out on starter compounds having active hydrogen atoms generally at temperatures of 20 to 200 ° C, preferably in the range of 40 up to 180 ° C, particularly preferably at temperatures from 50 to 150 ° C. The reaction can be carried out at total pressures from 0.0001 to 20 bar. The poly addition can be in bulk or an inert, organic solvent such as toluene and / or THF. The amount of solvent is more common example, 10 to 30 wt .-%, based on the amount of the polyether to be produced polyols.

The catalyst concentration is chosen so that under the given reaction conditions a good mastery of the polyaddition reaction is possible. The The catalyst concentration is generally in the range from 0.0005% by weight 1 wt .-%, preferably in the range of 0.001 wt .-% to 0.1 wt .-%, particularly be preferably in the range of 0.001 to 0.0025% by weight, based on the amount of constituting polyether polyol.

The (number average) molecular weights of the process according to the invention The polyether polyols produced are in the range from 500 to 100,000 g / mol, preferably in the range from 1,000 to 50,000 g / mol, particularly preferably in the range from 2,000 to 20,000 g / mol.

The polyaddition can be carried out continuously or batchwise, e.g. B. in a batch or be carried out in a semi-batch process.  

The catalysts of the invention can because of their significantly increased Akti very low concentrations (25 ppm and less, based on the amount of polyether polyol to be produced). Are they in counter were the polyether polyols prepared according to the catalysts of the invention position of polyurethanes used (plastics manual, vol. 7, polyurethanes, 3rd ed. 1993, pp. 25-32 and 57-67), can be based on removal of the catalyst the polyether polyol can be dispensed with, without the product qualities of the NEN polyurethane are adversely affected.  

Examples Catalyst preparation Example A Preparation of a DMC catalyst with cholic acid sodium salt (Catalyst A)

A solution of 6.2 g (45.75 mmol) of zinc chloride in 10 ml of distilled water is added to a solution of 2 g (6 mmol) of potassium hexacyanocobaltate in 35 ml of distilled water with vigorous stirring (24,000 rpm). Immediately afterwards, a mixture of 25 g of tert-butanol and 25 g of distilled water is added to the suspension formed and then stirred vigorously for 10 minutes (24,000 rpm). A mixture of 0.5 g of cholic acid sodium salt (Fluka Chemie AG, CH-9471 Buchs), 0.5 g of tert-butanol and 50 g of distilled water is then added and the mixture is stirred for 3 minutes (1,000 rpm). The solid is isolated by filtration, then stirred for 10 min with a mixture of 35 g of tert-butanol, 15 g of distilled water and 0.5 g of sodium cholate (10,000 rpm) and filtered again. Finally, the mixture is stirred again for 10 min with a mixture of 50 g of tert-butanol and 0.25 g of sodium cholic acid (10,000 rpm). After filtration, the catalyst is dried to constant weight at 50 ° C. and normal pressure.
Yield of dried powdered catalyst: 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

Example B Preparation of a DMC catalyst with L-α-lecithin (Catalyst B)

The procedure was as in Example A, but L-α-lecithin (from Eigelb, Fluka Chemie AG, CH-9471 Buchs) was used instead of cholic acid sodium salt.
Yield of dried powdery catalyst: 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, L-α-lecithin = 12.0% by weight

Example C Preparation of a DMC catalyst with N-lauroylsarcosine sodium salt (catalyst C)

The procedure was as in Example A, but N-lauroylsarcosine sodium salt (Fluka Chemie AG, CH-9471 Buchs) was used instead of cholic acid sodium salt.
Yield of dried powdery catalyst: 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, N-lauroylsarcosine sodium salt = 6.2% by weight

Example D (comparative example)

Production of a DMC catalyst using tert-butanol without ionic surface- or surface-active compound (catalyst D, synthesis according to JP-A 4145123).

A solution of 10 g (73.3 mmol) of zinc chloride in 15 ml of distilled water is added to a solution of 4 g (12 mmol) of potassium hexacyanocobaltate in 75 ml of distilled water with vigorous stirring (24,000 rpm). Immediately afterwards, a mixture of 50 g of tert-butanol and 50 g of distilled water is added to the suspension formed and then stirred vigorously for 10 minutes (24,000 rpm). The solid is isolated by filtration, then stirred for 10 minutes with 125 g of a mixture of tert-butanol and distilled water (in a weight ratio of 70/30) (10,000 rpm) and filtered again. Finally, the mixture is stirred again for 10 min with 125 g of tert-butanol (10,000 rpm). After filtration, the catalyst is dried to constant weight at 50 ° C. and normal pressure.
Yield of dried powdered catalyst: 3.08 g
Elemental analysis:
Cobalt = 13.6% by weight, zinc = 27.4% by weight, tert-butanol = 14.2% by weight.

Manufacture of polyether polyols General implementation

In a 500 ml pressure reactor, 50 g of polypropylene glycol starter (pay average molecular weight = 1,000 g / mol) and 3 to 5 mg of catalyst (15 to 25 ppm, based on the amount of the polyether polyol to be produced) under protection submitted gas (argon) and heated to 105 ° C with stirring. Then will Propylene oxide (approx. 5 g) was added all at once until the total pressure reached 2.5 bar has risen. Further propylene oxide is only metered in again when a accelerated pressure drop in the reactor is observed. This accelerated pressure waste indicates that the catalyst is activated. Then the rest Propylene oxide (145 g) continuously at a constant total pressure of 2.5 bar added. After complete propylene oxide dosing and 2 hours after-reaction time at 105 ° C volatile components are distilled off at 90 ° C (1 mbar) and on finally cooled to room temperature.

The polyether polyols obtained were determined by determining the OH numbers, the Dop and the viscosities.

The course of the reaction was based on time-conversion curves (propylene oxide ver need [g] vs. Response time [min]) followed. From the intersection of the tangent the steepest point of the time-sales curve with the extended baseline of the curve the induction time was determined. The decisive ones for the catalyst activity Propoxylation times correspond to the period between catalyst activation (End of induction period) and end of propylene oxide metering. The Total reaction time is the sum of induction and propoxylation time.  

example 1

Preparation of polyether polyol with catalyst A (15 ppm)
Induction time: 230 min
Propoxylation time: 95 min
Total reaction time: 325 min
Polyether polyol: OH number (mg KOH / g): 28.9
Double bond content (mmol / kg): 4
Viscosity 25 ° C (mPas): 982
Without removing the catalyst, the metal content in the polyol is: Zn = 4 ppm, Co = 2 ppm.

Example 2

Preparation of polyether polyol with catalyst B (25 ppm)
Induction time: 125 min
Propoxylation time: 140 min
Total reaction time: 265 min
Polyether polyol: OH number (mg KOH / g): 29.5
Double bond content (mmol / kg): 6
Viscosity 25 ° C (mPas): 921

Example 3

Preparation of polyether polyol with catalyst C (25 ppm)
Induction time: 350 min
Propoxylation time: 40 min
Total reaction time: 390 min
Polyether polyol: OH number (mg KOH / g): 30.4
Double bond content (mmol / kg): 6
Viscosity 25 ° C (mPas): 842

Example 4 (comparison)

Catalyst D (15 ppm) shows under the reaction conditions described above no activity even after 14 h induction time.

When using 50 ppm of catalyst D, the induction time was approx. 9 h. The Propoxylation time was more than 12 hours, being in the course of the reaction Catalyst deactivation occurred.

Examples 1-3 show that the new DMC catalysts according to the invention because of their significantly increased activity in polyether polyol production in so low concentrations that can be used to separate the Catalyst from which the polyol can be dispensed with.

Claims (12)

1. Containing double metal cyanide (DMC) catalyst

• a) one or more double metal cyanide compounds,
• b) one or more organic complex ligands different from c), and
• c) one or more ionic surface or surface-active compounds.

2. DMC catalyst according to claim 1, additionally containing d) water and / or e) water-soluble metal salt. 3. DMC catalyst according to claim 1 or 2, wherein the double metal cyanide Ver bond is zinc hexacyanocobaltate (III). 4. DMC catalyst according to any 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, wherein the catalyst 1 up to 80% by weight of one or more ionic surfaces or interfaces contains active compound (s). 6. DMC catalyst according to one of claims 1 to 5, wherein the ionic surface or surface active compound a hydrophilic anionic Group contains.   7. DMC catalyst according to any one of claims 1 to 5, wherein the ionic upper surface- or surface-active compound a hydrophilic cationic Group contains. 8. DMC catalyst according to one of claims 1 to 5, wherein the surface or surface-active compound a hydrophilic zwitterionic group contains. 9. A method for producing a DMC catalyst comprising the steps

• a) implementation in aqueous solution of
  • 1. α) metal salts with metal cyanide salts
  • 2. β) organic complex ligands which are not ionic surface-active or surface-active compounds, and
  • 3. γ) ionic surface or interface-active compounds,
• b) isolating, washing and drying the catalyst obtained in step i).

10. Process for the preparation of polyether polyols by polyaddition of Alkylene oxides to starter compounds having active hydrogen atoms gene, in the presence of one or more DMC catalysts according to one of the Claims 1 to 8. 11. polyether polyol which can be prepared by the process according to claim 11. 12. Use of one or more DMC catalysts according to one of the An Proverbs 1 to 8 for the production of polyether polyols by polyaddition of alkylene oxides to starter compounds containing active hydrogen atoms fertilize.