EP1189695A1

EP1189695A1 - Suspensions of platelike multimetal cyanide compounds, their production and the use thereof for producing polyether alcohols

Info

Publication number: EP1189695A1
Application number: EP00938659A
Authority: EP
Inventors: Georg Heinrich Grosch; Kathrin Harre; Jörg Erbes; Reinhard Lorenz; Stephan Bauer; Thomas Ostrowski; Eva Baum; Dieter Junge; Edward Michael Dexheimer
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 1999-06-02
Filing date: 2000-05-19
Publication date: 2002-03-27
Also published as: AR024177A1; WO2000074843A1; US20050004343A1; AU5395800A; US6800583B2; MXPA01011992A; US20020006864A1

Abstract

The invention relates to a catalyst suspension for carrying out the ring-opening polymerization of alkylene oxides containing; a) at least one multimetal cyanide compound having a crystalline structure and a content of platelike particles of at least 30 wt. % with regard to the multimetal cyanide compound; b) at least one organic complexing agent and/or; c) water and/or; d) at least one polyether and/or; e) at least one surface-active substance with the provision that at least constituent a) and at least two constituents b) to e) must be present.

Description

PLATE-SHAPED SUSPENSIONS

MULTI-METAL CYANIDE COMPOUNDS, THEIR PRODUCTION END

THEIR USE OF POLYETHER ALCOHOLS Description

The invention relates to suspensions of multimetal cyanide compounds, their preparation and their use.

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, onto H-functional starter substances. Mostly basic metal hydroxides or salts are used as catalysts, the potassium hydroxide being of the greatest practical importance.

In the synthesis of polyether alcohols with long chains, such as those used especially for the production of flexible polyurethane foams, as chain growth progresses, side reactions occur which lead 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. For this purpose, the alkoxylation catalysts used in particular are specifically changed. For example, EP-A-268 922 proposes using cesium hydroxide as the catalyst. Although this can reduce the unsaturated content, 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 contents 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. For example, DD-A-203 735 and DD-A-203 734 describe the preparation of polyetherols using zinc hexacyano cobaltate.

The production of zinc hexacyanometalates is also known. These catalysts are usually produced by solutions of metal salts, such as zinc chloride, with solutions of

Alkali or alkaline earth metal cyanometalates, such as potassium hexacyano cobaltate, are implemented. The resulting precipitation suspension As a rule, a water-miscible component containing heteroatoms is added 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. This component is also referred to as an organic complexing agent or organic ligand. Such methods are described, for example, in US 3,278,457, US 3,278,458, US 3,278,459, US 3,427,256, US 3,427,334, US 3,404,109, US 3,829,505, US 3,941,849,

EP 283,148, EP 385,619, EP 654,302, EP 659,798, EP 665,254,

EP 743,093, EP 755,716, US 4,843,054, US 4,877,906, US 5,158,922,

US 5,426,081, US 5,470,813, US 5,482,908, US 5,498,583,

US 5,523,386, US 5,525,565, US 5,545,601, JP 7,308,583, JP 6,248,068, JP 4,351,632 and US-A-5, 545, 601.

DD-A-148 957 describes the production of zinc hexacyanoiridate and its use as a catalyst in the production of polyether alcohol. Hexacanoiridic acid is used as a starting material. This acid is isolated as a solid and used in this form.

EP 862,947 describes the preparation of double metal cyanide complex compounds using hexacyanometal acids, in particular hexacyanocobaltoic acid or the aqueous solutions thereof as starting material. The double metal cyanides produced according to EP 862,947 have a high reactivity for the ring-opening polymerization of alkylene oxides.

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. One focus of the work in this area focuses on multimetal cyanide compounds that are amorphous. The preparation of such multimetal cyanide compounds is disclosed, inter alia, in EP 654,302. However, it could be shown that the activity of these catalysts can be increased further by incorporating polymers. For example, EP 700,949 describes double metal cyanide complexes with increased reactivity which contain between 5 and 80 percent by weight, based on the catalyst, of polyethers with a molecular weight greater than 500 daltons. WO 97 / 40,086 describes double metal cyanide catalysts with increased reactivity which contain between 5 and 80% by weight of polyethers with molar masses of less than 500 daltons. WO 98/16310 discloses double metal cyanides which contain between 2 and 80% by weight of functionalized polymers, but no polyethers. The in EP-A-700, 949, WO-A-97/40, 086 and Double metal cyanide catalysts disclosed in WO-A-98/16, 310 are generally amorphous. According to the teaching of WO 98/16,310 (page 2, lines 16-22), the best currently known double metal cyanide catalysts have a low degree of crystallinity. The preferred catalysts are essentially non-crystalline (page 3, lines 10-11).

Multimetal cyanide catalysts are mostly used in the form of powder for the production of polyether alcohols. US 4,477,589 and US 4,472,560 describe suspensions of multimetal cyanide compounds in propoxylated glycerol with contents of less than 5% by weight of multimetal cyanide compound. US Pat. No. 5,639,705 and US Pat. No. 5,714,639 describe paste-shaped catalysts which consist of 10 to 60% by weight of multimetal cyanide compound, 40 to 90% by weight of organic complexing agent and 1 to 20% by weight of water.

It would also be desirable to use crystalline multimetal cyanide compounds in a form so that they have the highest possible catalytic activity.

The task was surprisingly achieved by suspending crystalline multimetal cyanide compounds in organic or inorganic liquids and using them in this form as catalysts. It is particularly advantageous if the suspended multimetal cyanide compound has a platelet-shaped morphology.

The invention therefore relates to a catalyst suspension for the ring-opening polymerization of alkylene oxides

a) at least one multimetal cyanide compound with a crystalline structure and a content of platelet-shaped particles of at least 30% by weight, based on the multimetal cyanide compound, and b) at least one organic complexing agent c) water and / or d) at least one polyether and / or e) at least one surface-active substance with the proviso that at least component a) and at least two of the

Components b) to e) must be present.

The organic complexing agent b) is selected in particular from the group comprising alcohols, ethers, esters, ketones, aldehydes, carboxylic acids, amides, nitriles, sulfides and mixtures thereof. Polyether alcohols, in particular polyether alcohols, preferably hydroxyl-containing polyadducts of ethylene oxide, propylene oxide, butylene oxide, vinyloxirane, tetrahydrofuran, 1,1, 2-trimethylethylene oxide, 1,1,2, 2-tetramethylethylene oxide, 2, 2-dimethyloxetane, diisobutylene oxide, α-methyl styrene oxide and mixtures thereof are used.

Compounds selected from the group consisting of C ₄ -C ₆ alcohol alkoxylates, block copolymers of alkylene oxides of different hydrophilicity, alkoxylates of fatty acids and fatty acid glycerides, block copolymers of alkylene oxides and polymerizable acids and esters, in particular, are selected as surface-active substances e) used.

The crystalline multimetal cyanide compounds used according to the invention are preferably produced by the following process:

a) adding an aqueous solution of a water-soluble metal salt of the general formula M ¹ _m (X) _n , where M ^{1 contains} at least one metal ion selected from the group comprising Zn ²⁺ , Fe ²⁺ , Co ³⁺ , Ni ²⁺ , Mn ²⁺ , Co ²⁺ , Sn ²⁺ , Pb ²⁺ , Fe ³⁺ , Mo ⁴⁺ , Mo ⁶⁺ , Al ³⁺ , V ⁵⁺ , Sr ²⁺ , W ⁺ , W ⁶⁺ , Cu ²⁺ , Cr ²⁺ , Cr ³⁺ , Cd ⁺ , Hg ²⁺ , Pd ²⁺ , Pt ²⁺ , V ²⁺ , Mg ²⁺ , Ca ²⁺ , Ba ²⁺ and mixtures thereof,

X is at least one anion selected from the group consisting of halide, hydroxide, sulfate, carbonate, cyanide, thiocyanate, isocyanate, carboxylate, in particular formate, acetate, propionate, oxalate, nitrate and m and n are integers which represent the Values of M ¹ and X are sufficient,

to an aqueous solution of a cyanometalate compound of the general formula H _a M ² (CN) _b (A) _c , where M ^{2 contains} at least one metal ion selected from the group comprising Fe ²⁺ , Fe ³⁺ , Co ³⁺ , Cr ³⁺ , Mn ²⁺ , Mn ³⁺ , Rh ³⁺ , Ru ²⁺ , Ru ³⁺ , V ⁴⁺ , V ⁵⁺ , Co ²⁺ , Ir ³⁺ and Cr ⁺ and M ^{2 are} identical or different M ¹ can be,

H denotes hydrogen or a metal ion, usually an alkali metal, alkaline earth metal or an ammonium ion,

A is at least one anion selected from the group comprising halide, hydroxide, sulfate, carbonate, cyanate, thiocyanate, isocyanate, carboxylate or nitrate, in particular cyanide, where A can be the same or different X, and b is an integer greater than zero and a and c are integers larger or are zero, selected so that the

Electroneutrality of the cyanide compound is ensured,

where one or both solutions may optionally contain at least one water-containing, heteroatom-containing ligand which is selected from the group consisting of alcohols, ethers, esters, ketones, aldehydes, carboxylic acids, amides, sulfides or mixtures of at least two of the compounds mentioned,

and at least one of the two solutions contains a surfactant,

b) optionally combining the aqueous suspension formed in step a) with a ligand containing water-miscible heteroatoms, selected from the group described, which may be the same or different from the ligand from step a),

c) optionally separating the multimetal cyanide compound from the suspension.

The platelet-shaped multimetal cyanide compounds used according to the invention are crystalline and can have a cubic, tetragonal, trigonal, orthorhombic, hexagonal, monoclinic or triclinic crystal system. The definition of crystal systems and the space groups belonging to the aforementioned crystal systems can be found in "International tables for crystallography", Volume A, ed .: Theo Hahn, (1995).

For the preparation of the multimetal cyanide compounds which are used for the suspensions according to the invention, it is advantageous, but not necessary, to use the cyanometalate compound as the cyanometalate acid, since this does not lead to the inevitable formation of a salt as a by-product.

These cyanometalate hydrogen acids, which can preferably be used, are stable in aqueous solution and easy to handle. Their production can, for example, as in W. Klemm, W. Brandt, R. Hoppe, Z. Anorg. General Chem. 308, 179 (1961), starting from the alkali metal cyanometalate via the silver cyanometalate to cyanometalate hydrochloric acid. Another possibility is to convert an alkali metal or alkaline earth metal cyanometalate into a cyanometalate hydrogen acid using an acidic ion exchanger, as described, for example, in F. Hein, H. Lilie, Z. Anorg. General Chem. 270, 45 (1952), or A. Ludi, HU Güdel, V. Dvorak, Helv. Chim. Acta 50, 2035 (1967). Further possibilities for the synthesis of the cyanometalate hydrogen acids can be found, for example, in "Handbook of Preparative Inorganic Chemistry", G. Bauer (editor), Ferdinand Enke Verlag, Stuttgart, 1981. For the industrial preparation of these compounds, as used for the process according to the invention synthesis via ion exchangers is the most advantageous route. The cyanometalate-hydrochloric acid solutions can be processed immediately after synthesis, but it is also possible to store them for a longer period of time. Such storage should take place in the absence of light to prevent decomposition of the acid.

The proportion of acid in the solution should be greater than 80% by weight, based on the total mass of cyanometalate complexes, preferably greater than 90% by weight, in particular greater than 95% by weight.

The organic substances described above are used as ligands containing heteroatoms. In a preferred embodiment of the preparation process, the ligand containing no hetero atom-containing ligand is added to the solutions, and step b), the addition of ligand containing hetero atoms to the precipitation suspension, is also omitted. As mentioned above, only at least one surface-active compound is added to one or the two solutions in step a).

The surface-active compounds used according to the invention can be anionic, cationic, nonionic and / or polymeric surfactants.

In particular, nonionic and / or polymeric surfactants are used. In particular, fatty alcohol alkoxylates, coblock polymers of various epoxies with different hydrophilicity, castor oil alkoxylates or coblock polymers of epoxides and other monomers, such as acrylic acid or methacrylic acid, are selected from this group.

Fatty alcohol alkoxylates according to the invention have a fatty alcohol consisting of 8-36 carbons, in particular 10-18 carbons. This is alkoxylated with ethylene oxide, propylene oxide and / or butylene oxide. The polyether part of the fatty alcohol alkoxylate according to the invention can consist of pure ethylene oxide, propylene oxide or butylene oxide polyethers. Copolymers of two or three different alkylene oxides are also possible, or coblock polymers of two or three different alkylene oxides. Fatty alcohol alkoxylates, the Pure polyether chains are, for example, Lutensol AO brands

BASF AG. Fatty alcohol alkoxylates with coblock polymers as the polyether part are Plurafac LF brands from BASF Aktiengesellschaft.

The polyether chains particularly preferably consist of 2 to 50, in particular 3 to 15, alkylene oxide units.

Coblock polymers as surfactants contain two different polyether blocks, which differ in their hydrophilicity. Coblock polymers according to the invention can consist of ethylene oxide and propylene oxide (Pluronic brands, BASF Aktiengesellschaft). The water solubility is controlled by the lengths of the different blocks. The molecular weights are in the range from 500 Da to 20,000 Da, preferably from 1000 Da to 6000 Da, and in particular 1500-4000. In the ethylene / propylene copolymers, the ethylene oxide content is from 5 to 50% by weight and the propylene oxide Proportion of 50 to 95 wt .-%.

Invention copolymers of alkylene oxide with other monomers preferably have ethylene oxide blocks. Other monomers that may be used include butyl methacrylate (PBMA / PEO BE1010 / BE1030, Th. Goldschmidt), methyl methacrylate (PMMA / PEO ME1010 / ME1030, Th. Goldschmidt) or methacrylic acid (EA-3007, Th. Goldschmidt ).

The surface-active substances used should have a moderate to good water solubility.

To prepare the crystalline multimetal cyanide compounds used according to the invention, an aqueous solution of a cyanometalate-hydrogen acid or a cyanometalate salt is combined with the aqueous solution of a metal salt of the general formula M ¹ _m ( ^χ ) _n / where the symbols have the meaning explained above. Here, a stoichiometric excess of the metal salt is used. 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 add the metal salt solution and add the cyanometalate compound, but the reverse can also be used. 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 cyanometalate reactant solution based on the mass of cyanometalate reactant 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 the 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.

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 between 0.01 and 40% by weight. A content of 0.05 to 30% by weight is preferred.

A further preferred embodiment provides for the surface-active substances to be distributed proportionally over both educt solutions.

The ligands containing heteroatoms are added to the resulting suspension, in particular after the two starting material solutions have been combined, and here too thorough mixing must be ensured.

However, it is also possible to add all or part of the ligand to one or both of the starting material solutions. Due to the change in salt solubility, the ligand should preferably be added to the solution of the cyanometalate compound.

The content of the ligands in the resulting after the precipitation

Suspension should be 1 to 60% by weight, preferably 5 to 40% by weight, in particular 10 to 30% by weight.

The multimetal cyanide compounds used according to the invention can preferably have X-ray diffraction patterns, as shown in DE 197 42 978 FIGS. 3 and 4.

The multimetal cyanide compounds used to prepare the suspensions according to the invention preferably have primary crystals with a platelet-shaped habit.

Platelet-shaped particles are to be understood as meaning particles whose thickness is three times, preferably five times, particularly preferably ten times smaller than their length and width. The preferred catalyst according to the invention contains more than

30% by weight of such platelet-shaped crystals, preferably more than 50% by weight, particularly preferably more than 70% by weight and particularly preferably more than 90% by weight. The preferred multimetal cyanide compounds according to the invention are visible in scanning electron microscope images. Multimetal cyanide compounds which are less preferred according to the invention are often either in the form of rods or in the form of small cube-shaped or spherical crystals.

Depending on the characteristics of the platelet-like character of the particles and their quantity in the catalyst, it can happen that significant to strong changes in the intensity of the individual reflections are observed in the X-ray diffractogram compared to rod-shaped multimetal cyanide compounds with the same structure.

The multimetal cyanide compounds produced by precipitation according to the process described above can then be separated from the precipitation suspension by filtration or centrifugation. The separation can then be followed by one or more washes of the multimetal cyanide compounds. The

Washes can be performed 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 can then be dried at temperatures from 30 ° C. to 180 ° C. and pressures from 0.001 bar to 2 bar, preferably 30 ° C. to 100 ° C. and pressures from 0.002 bar to 1 bar.

Drying can also be omitted. Then a moist solid cake is obtained.

A preferred embodiment of the production process of the multimetal cyanide compound used according to the invention provides that, apart from the surface-active substance, no organic, heteroatom-containing ligands, as defined above, are added before, during or after the precipitation. In this embodiment of the production process, in which in addition to the surface-active substance no further organic, heteroatom-containing ligands are used, the multimetal cyanide compound is washed with water after separation from the precipitation suspension.

The multi-metal cyanide compounds prepared as described above are used for the production of polyether alcohols in the form of the suspensions according to the invention. Both the moist and the dried multimetal cyanide compounds can be used as the starting material for the suspensions according to the invention.

To produce the suspensions according to the invention, the powdery, dried multimetal cyanide compounds are dispersed as finely as possible in the suspension liquid by efficient dispersing in order to achieve the highest possible activity of the multimetal cyanide catalyst.

The suspension takes place in suitable apparatus with the input of high shear energy. Apparatus that allow a high input of shear energy have shear gradients between lxlO ² s ^_1 to lxlO ⁷ s ^-1 , preferably lxlO ³ s " ¹ to lxlO ⁶ s ^_1 , particularly preferably lxlO ⁴ s ^_1 to lxlO ⁶ s ^_1 To be bound by theory, it is assumed that the risk of agglomeration is particularly great due to the large contact surfaces in the case of platelet-shaped particles.

Such methods for the efficient production of a suspension which is as finely divided as possible include stirring under high shear forces, such as in homogenizers or Ultraturrax devices, and the use of dispersing machines, in particular pot and agitator ball mills, such as bead mills in general and those with small grinding beads (with, for example, 0.3 mm diameter), such as the double cylinder bead mills (DCP-Super Flow ^® ) from Draiswerken GmbH, Mannheim, or the centrifugal fluidized bed mills (ZWM) from Netzsch Gerätebau GmbH, Selb. If necessary, dissolvers can be used for the pre-dispersion. Dispersants known to those skilled in the art, such as, for example, lecithin, Zn oleate, Zn stearate, can also be used in small amounts. Furthermore, all methods are suitable which allow powder to be dispersed as finely as possible in liquids.

The dispersion can take place at temperatures from 10 ° C. to 150 ° C., preferably 30 ° C. to 120 ° C.

Dispersing liquids can be polyethers, organic liquids or water, and mixtures thereof.

Compounds with molecular weights from 150 to 6000 daltons and functionalities from 1 to 8 can be used as the polyether. Polyethers with molecular weights of 150 to 2000 daltons and functionalities of 1 to 3, in particular molecular weights of 150 to 800 daltons are preferably used. If the predried multimetal cyanide compound is suspended in organic liquids, suspensions with solids contents of less than 10% by weight are preferred. Solids contents of less than 5% by weight are particularly preferred. Compounds containing heteroatoms and hydrocarbons or mixtures thereof can be used as organic liquids. Compounds that have a vapor pressure greater than 0.005 bar at 100 ° C.

If the predried multimetal cyanide compound is suspended in water, suspensions with solids contents of less than 20% by weight and pastes with solids contents of less than 60% by weight are preferred. The water content in the pastes and suspensions should then be above 20% by weight.

Drying is preferably dispensed with. The moist multimetal cyanide compounds are then used to prepare the suspensions according to the invention.

For this purpose, a suspension is produced from the multimetal cyanide compound after the precipitation and separation from the precipitation suspension, as well as after washing the multimetal cyanide compound, either on the filtering device or externally with subsequent filtration, without drying, from the moist multimetal cyanide compound. The multimetal cyanide compound, like the dried multimetal cyanide compounds, can be suspended in the above-mentioned dispersing media. The methods which have been described for producing a suspension which is as finely divided as possible in the dried multimetal cyanide compounds can also be used in the dispersion of the undried multimetal cyanide compounds.

When using moist multimetal cyanide compounds for the preparation of suspensions with at least one polyether or a similar high-boiling liquid, in a preferred embodiment, temperature and vacuum can be applied simultaneously during the dispersion in order to remove volatile constituents, e.g. Water or organic ligands to remove. Vacuum is understood to mean both normal vacuum stripping up to pressures of 0.001 bar and the combination of vacuum treatment and stripping with inert gases such as nitrogen, argon, helium etc. The temperature can be between 10 ° C and 150 ° C, preferably 30 ° C and 120 ° C.

In the case of multi-metal cyanide suspensions in polyether, suspensions with solids contents of less than 20% by weight are preferred. Solids contents of less than 10% by weight and particularly preferably less than 5% by weight are particularly preferred. If you suspend the undried one Multimetal cyanide compound in organic liquids, as described above, suspensions with solids contents of less than 10% by weight are preferred. Solids contents of less than 5% by weight are particularly preferred. If the undried multimetal cyanide compound is suspended in water, suspensions with solids contents of less than 20% by weight and pastes with solids contents of less than 60% by weight are preferred. The water content in the pastes and suspensions should then be above 20% by weight.

If the starting materials used to prepare the multimetal cyanide compound are cyanometalic acid and the metal salt used is a salt of an acid which has at least a vapor pressure greater than 0.005 bar at 100 ° C., the suspensions according to the invention can be prepared according to the following advantageous embodiment. The precipitation is carried out in the presence of the surface-active agent and optionally the organic ligand. If an organic ligand is used, the organic ligand should also have a vapor pressure greater than 0.005 bar at 100 ° C. After the starting material has been combined, polyether is added to the precipitation suspension and, if appropriate, the acid formed during the precipitation, the water and at least some of the organic ligands are distilled off under vacuum. According to the invention, the remaining suspension has a solids content of less than 20% by weight and a polyether content of more than 80% by weight. The possible polyethers are defined above. Polyether alcohols with molecular weights of 150 to 2000 daltons are preferred, so that the resulting suspension can be used directly as a catalyst for the preparation of polyether alcohols.

The multimetal cyanide suspensions produced 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 ones Starter substances. Catalyst concentrations used are smaller than 1 wt .-%, preferably less than 0.5 wt .-%, particularly preferably less than 1000 ppm, particularly preferably less than 500 ppm, especially preferably less than 100 ppm ^¬ be subjected to the total weight of the polyetherol. The polyetherols can be prepared either continuously or batchwise. The synthesis takes place in the suspension procedure. The temperatures used in the synthesis are between 50 ° C and 200 ° C, with 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, 1,2-epoxypropane, 1,2-methyl-2-methylpropane, 1,2-epoxybutane, 2,3-epoxybutane, can be used , 1, 2-methyl-3-methylbutane, 1, 2-epoxypentane, 1, 2-methyl-3-methylpentane, 1, 2-epoxyhexane, 1, 2-epoxyheptane, 1, 2-epoxyoctane, 1, 2 -Epoxynonan, 1, 2-Epoxydecan, 1, 2-Epoxyundecan, 1,2-Epoxydodecan, styrene oxide, 1, 2-Epoxycyclopentan, 1, 2-Epoxycyclohexan, (2, 3-Epoxypropyl Jbenzol, Vinyloxiran, 3-Phenoxy -l, 2-epoxypropane, 2,3-epoxymethyl ether, 2,3-epoxyethyl ether, 2,3-epoxyisopropyl ether, 2,3-epoxy-l-propanol, (3,4-epoxybutyl) stearate, 4,5- Epoxypentyl acetate, 2,3-epoxypropane methacrylate, 2,3-epoxypropane acrylate, glycidyl butyrate, methyl glycidate, ethyl 2,3-epoxy butanoate, 4- (trimethylsilyl) butane-1,2-epoxide, 4- (triethylsilyl) butane 1,2-epoxide, 3- (PerfluoromethyDpropenoxid, 3- (Perflu oroethyl) propenoxide, 3- (perfluorobutyl) propenoxide, 4- (2, 3-epoxypropy) morpholine, 1- (oxiran-2-ylmethyl) pyrrolidin-2-one, as well as any mixtures of at least two of the compounds mentioned become.

Ethylene oxide, 1, 2-epoxypropane, 1, 2-epoxybutane, styrene oxide, vinyloxirane and any mixtures thereof, in particular ethylene oxide, 1, 2-epoxypropane, and mixtures of ethylene oxide, 1, 2-epoxypropane are preferred.

The invention is illustrated by the following examples.

Patent examples

Production of hexacyanocobaltic acid

71 strongly acidic ion exchanger which was in the sodium form (Amberlite 252 Na ^®, Fa. Rohm & Haas) were charged in an exchanger (length, volume 7.71). The ion exchanger was then converted to the H form by passing 10% hydrochloric acid at a rate of 2 bed volumes per hour over the exchange column for 9 hours until the sodium content in the discharge was less than 1 ppm. The ion exchanger was then washed neutral with water.

The regenerated ion exchanger was now used to produce a substantially alkali-free hexacyanocobaltic acid. For this purpose, a 0.24 molar solution of potassium potassium hexacyanocobaltate in water was passed over the exchanger at a rate of one bed volume per hour. After 2.5 bed volume, the potassium hexacyanocobaltate solution was changed to water. The 2.5 bed volumes obtained had an average content of

Hexacyanocobaltic acid of 4.5 wt .-% and alkali contents smaller

1 ppm.

The hexacyanocobaltate used for the further examples

5 acid solutions were diluted with water accordingly.

Comparative Example 1

200 ml of an aqueous solution of hexacyanocobaltoic acid (4.4% by weight of 10 H ₃ [Co (CN) ₆ ], potassium content <1 ppm) were heated to 40 ° C. and then with stirring (blade stirrer, U = 500 min ^{- 1} ) with a solution of 17.88 g of Zn (II) acetate dihydrate in 60 g of water. 35 g ter were then added to the suspension. -Butanol given. The suspension was stirred at 40 ° C for a further 30 min. 15 The solid was then filtered off and tert on the filter with 200 ml. -Butanol washed. The solid thus treated was dried in vacuo at 50 ° C. for 16 hours.

The X-ray diffractogram of the double metal cyanide obtained in this way could be indicated monoclinically, the images on the scanning electron microscope showed rod-shaped particles.

Comparative Example 2

300 ml of an aqueous hexacyanocobaltoic acid solution (2.2% by weight 25 H ₃ [Co (CN) ₆ ], potassium content <1 ppm) were heated to 40 ° C. and with stirring (blade stirrer, U = 500 min ^{- 1} ) 15 ml of Pluronic PE 6100 (BASF Aktiengesellschaft, coblock polymer from PO and EO) are added and dissolved. A solution of 13.38 g of Zn (II) acetate dihydrate in 30 50 g of water was then added with stirring (blade stirrer, U = 500 min ^-1 ). 50 g of tert were then added to the suspension. -Butanol given. The suspension was stirred at 40 ° C for a further 30 min. The solid was then filtered off and tert with 200 ml on the filter. -Butanol washed. The solid thus treated was dried in vacuo at 50 ° C. for 16 h. 35 The X-ray diffractogram of the double metal cyanide obtained in this way showed two phases, one of which could be indicated monoclinically and the other cubically, the images on the scanning electron microscope showed larger platelet-shaped particles and traces of small cubic particles.

40

Comparative Example 3

300 g of an aqueous hexacyanocobaltoic acid solution (2.2% by weight of H ₃ [Co (CN) ₆ ], potassium content 1 ppm) were heated to 40 ° C. and 45 with stirring (paddle stirrer, U = 500 min ^-1 ) 30 ml of Pluronic PE 6100 (BASF Aktiengesellschaft, coblock polymer from PO and EO) added and dissolved. The mixture was then stirred (blade stirrer, U = 500 min ^-1 ) a solution of 13.38 g of Zn (II) acetate dihydrate in 50 g of water was added. 50 g of tert were then added to the suspension. -Butanol given. The suspension was stirred at 40 ° C for a further 30 min. The solid was then filtered off and tert on the filter with 200 ml. -Butanol washed. The solid thus treated was dried in vacuo at 50 ° C. for 16 h. The X-ray diffractogram of the double metal cyanide obtained in this way showed two phases, one of which could be indicated monoclinically and the other cubically, the images on the scanning electron microscope showed larger platelet-shaped particles and traces of small cubic particles.

Comparative Example 4

200 g of an aqueous hexacyanocobaltoic acid solution (3.7% by weight

H ₃ [Co (CN) ₆ -, potassium content 1 ppm) were heated to 40 ° C. and, with stirring (paddle stirrer, U = 500 min ^-1 ), 0.5 ml of Plurafac LF 400 (BASF Aktiengesellschaft) were added and dissolved. A solution of 14.9 g of Zn (II) acetate dihydrate in 60 g of water was then added with stirring (blade stirrer, U = 500 min ^-1 ). 35 g of tert were then added to the suspension. -Butanol given. The suspension was stirred at 40 ° C for a further 30 min. The solid was then filtered off and tert on the filter with 200 ml. -Butanol washed. The solid thus treated was dried in vacuo at 50 ° C. for 16 hours.

The X-ray diffractogram of the double metal cyanide obtained in this way showed a crystalline phase that could be indicated monoclinically, the images on the scanning electron microscope showed platelet-shaped particles.

example 1

300 g of an aqueous solution of hexacyanocobaltoic acid (2.2% by weight of H ₃ [Co (CN) ₆ ], potassium content <1 ppm) were heated to 40 ° C. and with stirring (blade stirrer, U = 500 min ^-1 ) 10 ml of Pluronic PE 6100 (BASF Aktiengesellschaft) added and dissolved. A solution of 13.38 g of Zn (II) acetate dihydrate in 50 g of water was then added with stirring (blade stirrer, U = 500 min ^-1 ). 35 g of dipropylene glycol were then added to the suspension. The suspension was stirred at 40 ° C for a further 30 min. The solid was then filtered off and washed on the filter with 200 ml of dipropylene glycol. The moist solid was treated in vacuo at 50 ° C. for 16 h, then wet dispersed in dipropylene glycol, so that a 20% suspension was obtained. The X-ray diffractogram of the double metal cyanide obtained in this way showed a crystalline phase that could be indicated monoclinically, the images on the scanning electron microscope showed platelet-shaped particles.

Example 2

479.3 of an aqueous zinc acetate solution g (13.38 g zinc acetate dihydrate and 2.2 g of Pluronic ^® PE 6200 (BASF Aktiengesellschaft) dissolved in 150 g of water) were heated to 50 ° C. With stirring (Screw-type, stirring energy input: 1W / 1) was then within 20 min 558 g of an aqueous Hexacyanocobaltatsäure- solution (cobalt content: 9 g / 1, 1.5 wt .-% Pluronic ^® PE 6200 (BASF Aktiengesellschaft), based on the hexacyanocobaltic acid solution). After the hexacyanocobaltic acid had been completely metered in, stirring was continued at 50 ° C. for a further 5 minutes. The temperature was then reduced to 40 ° C. within one hour. The precipitated solid was separated from the liquid via a pressure suction filter and washed with water. The water-moist filter cake was then dispersed in so much water that a 5% by weight multi-metal cyanide suspension was formed.

Example 3

The synthesis was carried out in a cleaned and dried 1 l stirred autoclave. 150 g of polypropylene glycol were added to the stirred tank and 80 ppm of multimetal cyanide catalyst from Example 2 (solids content of multimetal cyanide compound, based on the mass of the end product) were added. The contents of the kettle were rendered inert with nitrogen and treated in vacuo at 127 ° C. for 1.25 h.

1 mol of propylene oxide was then metered in at 130 ° C. and the reaction started. The remaining propylene oxide was then metered in to a total amount of 620 g. The dosing time was 3 hours, the maximum pressure was 4 bar absolute. The product was worked up by vacuum distillation and filtration. Hydoxyl number: 57 mg KOH / g; Viscosity at 25 ° C: 320 mPas; Zn / Co content: 4.1 / <1 ppm. Comparative Example 5

The synthesis was carried out in a cleaned and dried 1 l stirred autoclave. 200 g of polypropylene glycol were added to the stirred tank and 250 ppm of catalyst from comparative example 1 were added. The kettle contents were rendered inert with nitrogen and treated in vacuo at 108 ° C. for 1 h.

1 mol of propylene oxide was then metered in at 115 ° C. and the reaction started. The remaining propylene oxide was then metered in up to a total amount of 800 g. The metering time was 1.1 hours, the maximum pressure was 3.9 bar absolute. The product was worked up by vacuum distillation and filtration. Hydoxyl number: 52 mg KOH / g; Viscosity at 25 ° C: 516 mPas; Zn / Co content: 62/25 ppm.

Example 4

The synthesis was carried out in a cleaned and dried 1 l stirred autoclave. 200 g of polypropylene glycol were added to the stirred tank and 100 ppm of catalyst from Example 1 were added. The contents of the kettle were rendered inert with nitrogen and treated in vacuo at 105 ° C. for 1 h. 1 mol of propylene oxide was then metered in at 110 ° C. and that

Waiting for the reaction to start. The remaining propylene oxide was then metered in up to a total amount of 800 g. The metering time was 1.6 hours, the maximum pressure was 4.2 bar absolute. The product was worked up by vacuum distillation and filtration. Hydoxyl number: 53 mg KOH / g; Viscosity at 25 ° C: 571 mPas; Zn / Co content: 2.7 / <2 ppm.

Comparative Example 6

The synthesis was carried out in a cleaned and dried 1 l stirred autoclave. 200 g of polypropylene glycol were added to the stirred tank and 125 ppm of catalyst from Comparative Example 2 were added. The contents of the kettle were rendered inert with nitrogen and treated in vacuo at 105 ° C. for 1 h.

1 mol of propylene oxide was then metered in at 115 ° C. and the reaction started. The remaining propylene oxide was then metered in to a total amount of 800 g. The dosing time was 0.75 hours, the maximum pressure was 4.1 bar absolute. The product was worked up by vacuum distillation and filtration. Hydoxyl number: 56 mg KOH / g;

Viscosity at 25 ° C: 470 mPas;

Zn / Co content: 6.5 / 2.2 ppm.

Comparative Example 7

The synthesis was carried out in a cleaned and dried 1 l stirred autoclave. 200 g of polypropylene glycol were added to the stirred tank and 125 ppm of catalyst from Comparative Example 3 were added. The contents of the kettle were rendered inert with nitrogen and treated in vacuo at 105 ° C. for 1 h.

1 mol of propylene oxide was then metered in at 115 ° C. and the reaction started. The remaining propylene oxide was then metered in to a total amount of 800 g. The dosing time was 1 hour, the maximum pressure was 4.6 bar absolute. The product was worked up by vacuum distillation and filtration. Hydoxyl number: 53 mg KOH / g; Viscosity at 25 ° C: 337 mPas; Zn / Co content: 14/5, 2 ppm.

Claims

claims

1. Catalyst suspension for the ring-opening polymerization of alkylene oxides, containing

a) at least one multimetal cyanide compound with a crystalline structure and a content of platelet-shaped particles of at least 30% by weight, based on the multimetal cyanide compound, and b) at least one organic complexing agent and / or c) water and / or d) at least one polyether and / or e) at least one surface-active substance with the proviso that at least component a) and at least two of components b) to e) must be present.

2. A catalyst suspension according to claim 1, characterized in that at least one of the multimetal cyanide compounds a) has a cubic crystal system.

3. A catalyst suspension according to claim 1, characterized in that at least one of the multimetal cyanide compounds a) has a tetragonal crystal system.

4. A catalyst suspension according to claim 1, characterized in that at least one of the multimetal cyanide compounds a) has an orthorhombic crystal system.

5. A catalyst suspension according to claim 1, characterized in that at least one of the multimetal cyanide compounds a) has a hexagonal crystal system.

6. A catalyst system according to claim 1, characterized in that at least one of the multimetal cyanide compounds a) has a trigonal crystal system.

7. A catalyst suspension according to claim 1, characterized in that at least one of the multimetal cyanide compounds a) has a monoclinic crystal system.

8. A catalyst suspension according to claim 1, characterized in that at least one of the multimetal cyanide compounds a) has a triclinic crystal system.

9. A catalyst suspension according to claim 1, characterized in that the organic complexing agent b) is selected from the group consisting of alcohols, ethers, esters, ketones, aldehydes, carboxylic acids, amides, nitriles, sulfides

5 and mixtures thereof.

10. A catalyst suspension according to claim 1, characterized in that the polyether d) is a polyether alcohol.

10 11. Catalyst suspension according to claim 1 and 9, characterized in that as polyether alcohols hydroxyl-containing polyadducts of ethylene oxide, propylene oxide, butylene oxide, vinyloxirane, tetrahydrofuran, 1, 1, 2-trimethylethylene oxide, 1, 1, 2, 2-tetramethylethylene oxide , 2, 2-dimethyl

15 oxetane, diisobutylene oxide, α-methylstyrene oxide and mixtures thereof can be used.

12. A catalyst suspension according to claim 1, characterized in that the surface-active substances e) are selected

20 are from the group containing C4 to C60 alcohol alkoxylates, block copolymers of alkylene oxides of different hydrophilicity, alkoxylates of fatty acids and fatty acid glycerides, block copolymers of alkylene oxides and polymerizable acids and esters. 5

13. A process for the preparation of catalyst suspensions according to claim 1 by combining a) an aqueous solution of a metal salt with b) an aqueous solution of a cyanometalate compound, characterized in that 0 optionally contains at least one of solutions a) and b) an organic complexing agent and / or the suspension formed after the reaction is treated with an organic complexing agent and / or the reaction is carried out in the presence of a surface-active substance

35, and the resulting suspension is optionally suspended in a polyether alcohol.

14. A process for the preparation of catalyst suspensions according to claim 1 by combining a) an aqueous solution of a metal salt with b) an aqueous solution of a cyanometalate compound, characterized in that optionally at least one of solutions a) and b) contains an organic complexing agent and / or the suspension formed after the union with an organic

45 complexing agent is treated and / or the combination is carried out in the presence of a surface-active substance, the multimetal cyanide formed after the combination The compound is separated off, dried and dispersed in water and / or a polyether with a shear rate between lxlO ² s ^_1 to lxlO ⁷ s ^-1 .

5 15. A process for the preparation of polyether alcohols by ring-opening polymerization of alkylene oxides, characterized in that a catalyst suspension according to claim 1 is used as the polymerization catalyst.

10 16. Polyether alcohols, producible according to claim 13.

15

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30

35

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45 Suspensions of multimetal cyanide compounds, their preparation and their use

Summary

The invention relates to a catalyst suspension for the ring-opening polymerization of alkylene oxides containing