MXPA00006212A - Improved double-metal cyanide catalysts for the production of polyether polyols - Google Patents

Abstract

The invention relates to new, improved double-metal cyanide (DMC) catalysts for the production of polyether polyols by polyaddition of alkyl propylene oxides and initiator compounds having active hydrogen atoms. The catalyst contains a double-metal cyanide compound, an organic complex ligand and between 2 and 80 weight percent, in relation to the quantity of catalyst, of a polycarbonate. These new improved catalysts offer significantly reduced induction periods and markedly raised activity for the production of polyether polyols.

Description

Improved bimetallic cyanide catalysts for the preparation of polyether polyols DESCRIPTION OF THE INVENTION The invention relates to new improved bimetallic cyanide (DMC) catalysts for the preparation 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 3 404 109, US 3 829 505, US 3 941 849 and US Pat. 5 158 922). The use of these DMC catalysts for the preparation 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 preparation of polyether polyols by alkaline catalysts, such as alkali hydroxides. The polyether polyols thus obtained can be processed into valuable polyurethanes (eg elastomers, foams, coatings). DMC catalysts 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 low molecular weight ligand, eg of an ether. Aqueous solutions of zinc chloride (in excess) and hexacyanocobaltate are mixed in a typical catalyst preparation by way of example.

PEF. 120920 potassium 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 700 949).

Zn3 [Co (CN) 6] 2 • x ZnCl2 • and H20 • z Glime From JP 4 145 123, US 5 470 813, EP 700 949, EP 743 093 and EP 761 708, improved DMC catalysts are known than using tert-butanol as an organic complex ligand (alone or in combination with a polyether (documents EP 700 949, EP 761 708)) make it possible to further reduce the proportion of monofunctional polyethers with terminal double bonds in the preparation of polyether polyols. In addition to this, the use of the improved DMC catalysts reduces the induction time in the polyaddition reaction of the alkylene oxides to corresponding initiator compounds and increases the activity of the catalyst. It is therefore an object of the present invention to provide improved DMC catalysts for the polyaddition of alkylene oxides to corresponding initiator compounds which, compared to the types of catalysts known hitherto, have a considerably reduced induction time and, at the same time, a significantly improved catalyst activity. . This leads to shortened total reaction times and cycle times of polyether ether production to an improved process efficiency. Ideally, upon raising the activity the catalyst can then be used in such low concentrations that otherwise expensive catalyst separation is no longer necessary and the product can be used directly for polyurethane applications. Surprisingly it has now been found that DMC catalysts containing 2-80% by weight, based on the amount of catalyst, of a polycarbonate, have clearly reduced induction times and at the same time strongly increased activity in the preparation of polyether polyols. The object of the present invention are improved bimetallic cyanide (DMC) catalysts consisting of a) a bimetallic cyanide compound as well as b) an organic complex ligand, characterized in that they contain from 2 to 80% by weight, based on the amount of prepared catalyst, of a polycarbonate. In the catalysts according to the invention, water, preferably 1 to 10% by weight and / or water-soluble metal salt, preferably 5 to 25% by weight, of the preparation of the bimetallic cyanide compound can optionally be present.

The bimetallic cyanide compounds a) suitable for the catalysts according to the invention are the reaction products of a water-soluble metal salt and a water-soluble metal cyanide salt. The water-soluble metal salt preferably has the general formula M (X) n in which 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. X is an anion, 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 6 3. Examples of suitable metal salts are zinc chloride, zinc bromide, zinc acetate, zinc acetylacetonate, zinc benzoate, zinc nitrate, iron (II) sulfate, bromide. of iron (II), iron (II) chloride, cobalt (II) chloride, cobalt thiocyanate (II), nickel (II) chloride and nickel (II) nitrate. Mixtures of different metal salts can also be used. The water-soluble metal cyanide salt preferably has the general formula (Y) aM '(CN) b (A) c, wherein 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 may contain one or more of these metals. And it is an alkali metal ion or an alkaline earth metal ion. A is an anion selected from the group of halides, hydroxides, sulfates, carbonates, cyanates, thiocyanates, isocyanates, isothiocyanates, carboxylates, oxalates or nitrates. Both a and b are integers (> 1), the values of a, b, and c being chosen so as to result in the electroneutrality of the metal cyanide salt; c preferably has the value 0. Examples of suitable water-soluble metal cyanide salts are hexacyanocobaltate (III) potassium, hexacyanoferrate (II) potassium, hexacyanoferrate (III) potassium, hexacyanocobaltate (III) calcium and hexacyanocobaltate (III) of lithium. Examples of suitable bimetal cyanide compounds a) which can be used in the catalysts according to the invention are zinc hexacyanocobaltate (III), zinc hexacyanoferrate (II), zinc hexacyanoferrate (III), hexacyanoferrate (II) nickel (II) and cobalt (II) hexacyanocobaltate (III). Other examples of suitable bimetallic cyanide compounds are listed, for example, in US 5 158 922 (column 8, lines 29-66).

Preferably zinc hexacyanocobaltate (III) is used.

The DMC catalysts according to the invention contain an organic complex ligand b), since these, for example, increase the activity of the catalyst. Suitable organic complex ligands are known in principle and are described in detail in the prior art (see, for example, column 6, lines 9-65 in US 5 158 922). The organic complex ligand is added either during the preparation of the catalyst or immediately after the precipitation of the catalyst. Usually the complex ligand is used in excess. Preferred complex ligands are water-soluble organic compounds with heteroatoms, which can form complexes with the bimetallic cyanide compound. 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, for example, ethanol, isopropanol, n-butanol, iso-butanol, sec-butanol and tert-butanol. Especially preferred is tert-butanol. The DMC catalysts according to the invention contain the bimetallic cyanide compounds in amounts of 20 to 90% by weight, preferably from 25 to 80% by weight, based on the amount of the catalyst prepared, and the organic complex ligands in amounts of 1 to 30, preferably 3 to 25% by weight, based on the amount of the catalyst prepared. The DMC catalysts according to the invention contain from 2 to 80% by weight, based on the amount of the catalyst, of a polycarbonate. Preferred catalysts contain from 5 to 50% by weight of polycarbonate. For the preparation of the catalysts according to the invention, suitable polycarbonates are high molecular weight substances with the structural characteristic characteristic of the carbonic acid ester group -0-C0-0 as a recurrent unit in the chain. They are generally obtained by polycondensation of polyfunctional hydroxyl compounds (in general bishydroxyl compounds, such as alkanediols or bisphenols) with carbonic acid derivatives, such as, for example, phosgene or bis- [chlorocarbonyloxy] compounds, diesters of carbonic acid or urea. Polycondensation of three or more components of polyfunctional polyhydroxy compounds (eg bisphenols) and carbonic acid derivatives is also possible. eg, vinyl monomers or polymers, halogen-bisphenols or bis- [4-hydroxy-phenyl] -sulfans, oxiranes, dicarboxylic acids or dicarboxylic dichlorides, phosphonic acids or phosphonic acid derivatives or silicon compounds. Other customary preparation methods for polycarbonates consist in the polymerization of cyclic (cyclic) diesters of carbonic acid, spirocyclic tetraesters of orthocarbonic acid and unsaturated diesters of carbonic acid, in the copolymerization of cyclic diesters of carbonic acid with other cyclic diesters of the acid carbon, lactones or with lactams and in the copolymerization of carbon dioxide with oxiranes or oxetanes. Methods for the preparation of polycarbonates are generally well known and are described in detail, for example, in "Houben-Weyl, Methoden der organischen Chemie", volume E20, Makromolekulare Stoffe, 4th edition, 1987, p. 1443-1457, "Ullmann's Encyclopedia of Industrial Chemistry," volume A21, 5th edition, 1992, p. 207-215 and "Encyclopedia of Polymer Science and Engineering," volume 11, 2nd edition, 1988, pp. 648-718.Preferably, polycarbonates having terminal hydroxy groups with average molar masses of less than 12,000 are used, determined by measurement of the index OH, which are generally obtained from aliphatic hydroxyl compounds (generally diols) by reaction with diaryl carbonate, dialkyl carbonate, dioxolanones, phosgene, chlorocarbonic acid esters or urea. Particular preference is given to polydiolcarbonates with average molar masses of 400 to 6000, determined by measurement of the OH Index, which are generally obtained from non-vicinal diols by reaction with diaryl carbonate, dialkyl carbonate, dioxolanones, phosgene, chlorocarbonic acid bis-esters or urea (see, for example, EP 292 772 and the documents cited therein) As non-local diols, the following are considered in this respect: 1,4-butanediol, n eopentyl glycol, 1, 5-pentanediol, 2-methyl-l, 5-pentanediol, 3-methyl-l, 5-pentanediol, 1,6-hexanediol, bis- (6-hydroxyhexyl) ether, 1,7-heptanediol, 1 , 8-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,4-bis-hydroxymethylcyclohexane, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, oxalkylation products of of diols with ethylene oxide and / or propylene oxide and / or tetrahydrofuran with molar masses of up to 1000, preferably of 200-700, as well as in particular cases the so-called "dimerodiols", which can be obtained by reduction of the two carboxyl groups of the so-called "dimer acids", which can be obtained in turn by dimerization of unsaturated vegetable fatty acids. The diols can be used alone or in mixtures. To a lesser extent, high-boiling monofunctional alcohols, such as phenylethyl alcohol, can be used., decanol, stearyl alcohol or lauryl alcohol. For the branching, small amounts of trifunctional and higher functionalizing alcohols can also be used, such as, for example, trimethylolethane, trimethylolpropane or pentaerythritol. For the reaction with the non-vicinal diols the following compounds can be used: diaryl carbonates, such as diphenyl carbonate, ditolyl, dixylyl and dinaphthyl, dialkyl carbonates, such as dimethyl carbonate, diethyl, dipropyl, dibutyl, diamyl and dicyclohexyl, dioxolanones, such as ethylene and propylene carbonate, 1,6-hexanediol bis-esters of chlorocarbonic acid, phosgene and urea. The reaction can be catalyzed in a customary manner with bases or transition metal compounds. Both the use of the organic complex ligand and that of the polycarbonate are necessary for the preparation of a DMC catalyst with reduced induction period and high activity (see Examples 7-8 and Comparative Examples 6 and 9). The analysis of the catalyst composition is usually carried out by elemental analysis and gravimetry. The catalysts according to the invention can be crystalline, partially crystalline or amorphous. The analysis of crystallinity is usually carried out by powder X-ray diffraction. The preparation of the improved DMC catalysts according to the invention is usually carried out in aqueous solution by reaction of metal salt (in excess) and metal cyanide salt in the presence of the organic complex ligand and the polycarbonate. In this connection, the aqueous solutions of the metal salt (eg zinc chloride, used in stoichiometric excess (at least 50% based on the metal cyanide salt)) and the salt of the salt are preferably first reacted. metal cyanide (eg potassium hexacyanocobaltate) in the presence of the organic complex ligand (eg tert-butanol), forming a catalyst suspension containing the bimetal cyanide compound (eg zinc hexacyanocobaltate), salt excess metal, water and the organic complex ligand. The organic complex ligand may in this respect be present in one or both aqueous solutions, or be added directly to the suspension after precipitation of the bimetallic cyanide compound. It has turned out to be advantageous to mix the aqueous solutions and the organic complex ligands under strong agitation. The suspension formed is then treated with the polycarbonate. The polycarbonate is preferably used in this connection in a mixture with water and an organic complex ligand. The isolation of the catalyst containing the polycarbonate from the suspension is carried out by known techniques, such as, for example, centrifugation or filtration. In order to increase the activity of the catalyst, it is advantageous to then wash the isolated catalyst with an aqueous solution of the organic complex ligand (eg by resuspension and subsequent re-isolation by filtration or centrifugation). In this way, for example, water-soluble by-products which adversely affect the polyaddition reaction, such as potassium chloride, of the catalyst according to the invention can be eliminated. Preferably the amount of organic complex ligand in the aqueous wash solution is between 40 and 80% by weight. In addition, it is advantageous to add some polycarbonate, preferably 0.5 to 5% by weight, to the aqueous wash 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, for example a mixture of the organic complex ligand and polycarbonate. Finally, the washed catalyst, optionally after spraying, is dried at temperatures of 20-100 ° C and at pressures of 0.1 mbar at normal pressure (1013 mbar). Another object of the invention is the use of the improved DMC catalysts according to the invention for the preparation of polyether polyol ether by alkylene oxide 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", English edition, 1992, vol. A21, pgs. 670-671. As starter compounds having active hydrogen atoms, compounds of molecular weights of 18 to 2000 and 1 to 8 hydroxyl groups are used. By way of example, mention may be made of: ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1-butanediol, hexamethylene glycol, bisphenol A, trimethylolpropane, glycerin, pentaerythritol, sorbitol, sugar cane, digested starch and water. It is advantageous to use those initiator compounds having active hydrogen atoms obtained, for example, by conventional alkaline catalysis of the above-mentioned low molecular weight initiators and to synthesize oligomeric alkoxylation products of molecular weights of 200 to 2000. The polyaddition catalyzed by The catalysts according to the invention of alkylene oxides to initiator compounds having active hydrogen atoms are generally carried out at temperatures of 20 to 200 ° C, preferably in the range of 40 to 180 ° C, particularly preferably at temperatures of 50 to 50 ° C. 150 ° C. The reaction can be carried out at normal pressure or at total pressures from 0 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 from 0.0005% by weight to 1% by weight, preferably in the range from 0.001% by weight to 0.1% by weight, based on the amount of the polyether polyol to be produced. The reaction times for the polyaddition are in the range of a few minutes to several days. The molecular weights of the polyether polyols produced according to the invention are in the range from 500 to 100000 g / mol, preferably in the range from 1000 to 50000 g / mol, particularly preferably in the range from 2000 to 20 000 g / mol. The polyaddition can be carried out continuously or by a discontinuous or semi-batch process. The catalysts according to the invention generally require an induction time of a few minutes to several days. By using the novel catalysts according to the invention, the induction times are clearly shortened in the preparation of polyether polyols in comparison with the DMC catalysts known hitherto. At the same time, the alkoxylation times are strongly reduced due to the substantially increased activity.

This leads to a shortening of the total reaction times (sum of the induction and alkoxylation times) typically by 65-80% compared to the DMC catalysts known hitherto. The catalysts according to the invention can be used, due to their clear greater activity, at such low concentrations (15 ppm and less, see Example 10) that generally for use in applications for polyurethanes the elimination of the polyol catalyst can be suppressed without the quality of the product is inconveniently affected.

Examples Preparation of the catalyst Comparative example 1 Preparation of a DMC catalyst with tert-butanol as an organic complex ligand without the use of polycarbonate (Catalyst A, synthesis according to JP 4 145 123) A solution of 10 g (73.3 mmol) of zinc chloride in 15 ml of distilled water was added with vigorous stirring to a solution of 4 g (12 mmol) of potassium hexacyanocobaltate in 75 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 for 10 min. The solid matter was isolated by filtration, then stirred for 10 min with 125 g of a mixture of tert-butanol and distilled water (70/30 w / w) and filtered again. Finally, it was stirred again 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%; Zinc = 27.35%; tert-Butanol = 14.2%; (Polycarbonate = 0%). Example 2 Preparation of a DMC catalyst with tert-butanol as an organic complex ligand and using an aliphatic polycarbonate (Catalyst B) To a solution of 4 g (12 mmol) of potassium hexacyanocobaltate in 70 ml of distilled water was added with vigorous stirring (24000 rpm) a solution of 12.5 g (91.5 mmol) of zinc chloride in 20 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 (24000 rpm) for 10 min. Then a mixture of 1 g of a triethylene glycol polycarbonate / tetraethylene glycol (triethylene glycol / tetraethylene glycol molar ratio = 1/1) was added with a mean molar mass of 1972 (determined by measurement of the OH number), 1 g of tert-butanol and 100 g of distilled water and stirred for 3 min (1000 rpm). The solid matter was isolated by filtration, then stirred (10000 rpm) for 10 min with a mixture of 70 g of tert-butanol, 30 g of distilled water and 1 g of the above polycarbonate and filtered again. Finally it was stirred (10,000 rpm) again for 10 min with a mixture of 100 g of tert-butanol and 0.5 g of the above polycarbonate. After filtering, the catalyst was dried at 50 ° C and under normal pressure to constant weight.

Dry pulverulent catalyst yield: 5.42 g Elemental analysis and thermogravimetric analysis: Cobalt = 10.5%, Zinc = 24.2%, tert-Butanol = 13.3%, Polycarbonate = 21.2%. Example 3 Preparation of a DMC catalyst with tert-butanol as an organic complex ligand and using an aliphatic polycarbonate (Catalyst C) As Example 2, but with: Use of a dipropylene glycol polycarbonate with a mean molar mass of 1968 (determined by measuring the OH number) instead of the polycarbonate of Example 2. Dry pulverulent catalyst yield: 5.33 g Elemental analysis and thermogravimetric analysis: Cobalt = 10.8%, Zinc = 24.4%, tert-Butanol = 20 , 2%, Polycarbonate = 15.0%. e emplo com grgtti Q 4 Preparation of a DMC catalyst using polycarbonate without tert-butanol as organic complex ligand (Catalyst D) To a solution of 4 g (12 mmol) of potassium hexacyanocobaltate in 70 ml of distilled water was added with vigorous stirring (24000 rpm) a solution of 12.5 g (91.5 mmol) of zinc chloride in 20 ml of distilled water. Immediately afterwards a mixture of 1 g of the polycarbonate of Example 3 and 100 g of distilled water was added to the formed suspension and then stirred vigorously (24000 rpm) for 10 min. The solid matter was isolated by filtration, then stirred (10000 rpm) for 10 min with a mixture of 1 g of the polycarbonate and 100 g of distilled water and filtered again. Finally, it was stirred (10000 rpm) again for 10 min with a mixture of 0.5 g of polycarbonate and 100 g of distilled water. After filtering, the catalyst was dried at 50 ° C and under normal pressure until constant weight. Dry pulverulent catalyst yield: 4.72 g Elemental analysis and thermogravimetric analysis: Cobalt = 10.7%, Zinc = 18.2%, Polycarbonate = 28.6%, (tert-Butanol = 0%). COMPARATIVE EXAMPLE 5 Preparation of a DMC catalyst with tert-butanol as an organic complex ligand and use of a polyether (Catalyst E, synthesis according to EP 700 949) A solution of 12.5 g (91.5 mmol) of chloride of zinc in ml of distilled water was added with vigorous stirring (24000 rpm) to a solution of 4 g (12 mmol) of potassium hexacyanocobaltate in 70 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 (24000 rpm) for 10 min. Then a mixture of 1 g of propylene glycol with a mean molar mass of 2000 (OH number = 56 mg KOH / g) was added, 1 g of tert-butanol and 100 g of distilled water and stirred (1000 rpm) for 3 min. The solid matter was isolated by filtration, then stirred (10000 rpm) for 10 min with a mixture of 70 g of tert-butanol, 30 g of distilled water and 1 g of the above polyether and filtered again. Finally, it was stirred (10000 rpm) again for 10 min with a mixture of 100 g of tert-butanol and 0.5 g of the above polyether. After filtering, the catalyst was dried at 50 ° C and under normal pressure to constant weight. Dry pulverulent catalyst yield: 6.23 g Elemental analysis and thermogravimetric analysis: Cobalt = 11.6%, Zinc = 24.6%, tert-Butanol = 3.0%, Polyether = 25.8%. Preparation of polyether polyols General implementation In a 500 ml pressure reactor, 50 g of polypropylene glycol were introduced under protective gas (argon) as initiator (molecular weight = 1000 g / mol) and 3-20 mg of catalyst (15-100 ppm, referred to 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 5 hours of reaction time at 105 ° C, the volatile fractions were removed by distillation at 90 ° C (1 mbar) and then cooled to room temperature.The obtained polyether polyols were characterized by determining the OH indices, the content of double bonds and the dispersions of the molar masses ^ / Mp (EM-MALDI-TOF) The development of the reaction was followed by transformation-time curves (consumption of propylene oxide [g] versus reaction time [min]) The induction times were determined by the tangent cut-off point err the steepest point of the transformation-time curve with the extension of the baseline of the curve The determinant propoxylation times for the activity of the catalyst correspond to the time interval between the activation of the catalyst (end of the induction time) 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. Comparative Example 6 Polyol ether preparation with catalyst A (100 ppm) Induction time: ~~ 290 min Propoxylation time: 165 min. Total reaction time: 455 min.

Polyol ether: OH number (mg KOH / g): 28.5 Content of double bonds (mmol / kg): 6 M "/ Mn: 1.12 Example 7 Preparation of polyol ether with catalyst B (100 ppm) Induction time: 95 min Propoxylation time: 40 min Total reaction time: 135 min Polyol ether: OH number (mg KOH / g): 28.8 Double bond content (mmol / kg): 6 Example 8 Polyol ether preparation with catalyst C (100 ppm) Induction time: 65 min Propoxylation time: 35 min. Total reaction time: 100 min.

Polyol ether: OH number (mg KOH / g): 28.7 Double bond content (mmol / kg): 6 M "/ Mn: 1.04 Comparative example 9 Polyol ether preparation with catalyst D (100 ppm) Induction time : > 700 min Propoxylation time: no activity A comparison between Examples 7-8 and Comparative Example 6 clearly indicates that in the preparation of polyether polyols with the DMC catalysts according to the invention containing an organic complex ligand (tere-butanol) and. a polycarbonatecompared to a DMC catalyst containing only one organic complex ligand (tert-butanol), clearly reduced induction times are observed and that at the same time the catalysts according to the invention possess a strongly increased activity (recognizable by the times of substantially reduced propoxylation). Comparative Example 9 indicates that a DMC catalyst that does not contain any organic complex ligand, but only a polycarbonate, is inactive. Example 10 Polyol ether preparation with catalyst C (15 ppm) Total reaction time: 310 min Polyol ether: OH number (mg KOH / g): 29.6 Content of double bonds (mmol / kg): 6 Mw / Mn: 1.06 Without elimination of the catalyst the content of metals in the polyol amounts to: Zn = 4 ppm, Co = 2 ppm. Example 10 indicates that the novel DMC catalysts according to the invention can be used in the preparation of polyether polyols, due to their clearly increased activity, in such low concentrations that the separation of the polyol catalysts can be suppressed. Example compare io 11 Polyol ether preparation with catalyst E (15 ppm) Total reaction time: 895 min Polyol ether: OH number (mg KOH / g): 29.8 Content of double bonds (mmol / kg): 6 M "/ Mn: 1.04 A comparison between Example 10 and Comparative Example 11 indicates that the novel DMC catalysts according to the invention containing an organic complex ligand (tert-butanol) and a polycarbonate, are substantially more active than the catalysts of high activity DMC known hitherto to contain an organic complex ligand (tert-butanol) and a polyether (with a molar mass comparable to that of the polycarbonate used in the catalysts according to the invention). The preparation of polyether polyols with the novel catalysts according to the invention is therefore possible with clearly reduced total reaction times. 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 (8)

Claims Having described the invention as above, the content of the following claims is declared as property:

1. Bimetallic cyanide (DMC) catalysts consisting of a) a bimetal cyanide compound, as well as b) an organic complex ligand, characterized in that they contain from 2 to 80% by weight, based on the amount of the prepared catalyst, of a polycarbonate .

2. DMC catalysts according to claim 1, characterized in that the bimetallic cyanide compound is zinc hexacyanocobaltate (III).

3. DMC catalysts according to claim 1, characterized in that the organic complex ligand is tert-butanol.

4. DMC catalysts according to claims 1 to 3, characterized in that they contain from 5 to 50% of a polycarbonate.

5. DMC catalysts according to claims 1 to 4, characterized in that they contain aliphatic polycarbonates having terminal hydroxy groups with average molar masses less than 12,000, determined by measurement of the OH number, which are obtained by reaction of polyfunctional aliphatic hydroxy compounds with carbonate of diaryl, dialkyl carbonate, dioxolanones, phosgene, bis-esters of chlorocarbonic acid or urea.

6. DMC catalysts according to claims 1 to 5, characterized in that they contain aliphatic polydiolcarbonates with average molar masses of 400 to 6000, determined by measurement of the OH number, which are obtained by reaction of non-vicinal diols with diaryl carbonate, dialkyl carbonate , dioxolanones, phosgene, bis-esters of chlorocarbonic acid or urea.

7. Process for the preparation of DMC catalysts according to claim 1, characterized in that excess metal salts are reacted with metal cyanide salts in the presence of the organic complex ligand and polycarbonate, the obtained catalyst is isolated, washed and then it dries.

8. Use of the DMC catalyst according to claim 1 for the preparation of polyether polyol ethers of alkylene oxides to initiator compounds having active hydrogen atoms.