WO1999044940A1

WO1999044940A1 - Method for producing double metal cyanide catalysts

Info

Publication number: WO1999044940A1
Application number: PCT/EP1999/001152
Authority: WO
Inventors: Georg Heinrich Grosch; Harald Larbig; Reinhard Lorenz; Dieter Junge; Eugen Gehrer; Ulrich Treuling
Original assignee: Basf Aktiengesellschaft
Priority date: 1998-03-05
Filing date: 1999-02-23
Publication date: 1999-09-10
Also published as: AR018316A1; DE19809538A1; AU2928099A

Abstract

The invention relates to a method for producing double metal cyanide compounds, comprising the following stages: a) reacting a solution of a metal salt of general formula M1m(X)n with a solution of a cyanometallate compound of formula HaM2(CN)b(A)c, M?1 and M2¿ being metal cations, X and A each representing an anion and a, b, c, m and n being whole numbers selected to guarantee the electroneutrality of the particular salt and at least one of the two solutions containing at least one water-soluble organic ligand containing heteroatoms; b) combining the resulting suspension with a water-miscible ligand which can be the same as or different from the ligand used in a); and c) separating the double metal cyanide compound from the suspension. At least one of the educt solutions used in a) contains at least one inert inorganic or organic solid which is insoluble in the educts and end products.

Description

Process for the preparation of double metal cyanide catalysts

description

The invention relates to a process for the preparation of double metal cyanide catalysts and their use as catalysts for the production of polyether alcohols with a low content of unsaturated components.

Polyether alcohols are used in large quantities for the production of polyurethanes. They are usually produced by base-catalyzed addition of lower alkylene oxides, mostly ethylene oxide and / or propylene oxides, to H-functional starting substances. Basic metal hydroxides or salts are mostly used as catalysts, with the potassium hydroxide having the greatest technical importance.

In the synthesis of polyether alcohols with long chains, such as those used in particular for the production of flexible polyurethane foams and polyurethane elastomers, side reactions occur as the chain grows, which leads to disruptions in the chain structure. The resulting by-products are called unsaturated components. They are monofunctional in terms of their OH functionality and lead to an impairment of the properties of the polyurethanes. There has therefore been no lack of attempts in the past to provide polyether alcohols with a reduced content of unsaturated constituents.

EP-A-268 922 proposes the use of cesium hydroxide as a catalyst for the production of polyether alcohol. This can reduce the unsaturated content, but cesium hydroxide is expensive and problematic to dispose of.

It is also known to use multimetal cyanide complex compounds, mostly zinc hexacyanometalates, for the production of polyether alcohols with low contents from unsaturated constituents. There is a large number of documents that describe the preparation of such compounds and their use as alkoxylation catalysts. The production of polyetherols using zinc hexacyanocobaltate is described in DD-A-203 735 and DD-A-203 734.

The production of zinc hexacyanometalates is also known. Solutions of metal salts, such as zinc chloride, are usually combined with solutions of alkali metal or alkaline earth metal cyanomes. 2 tallates, for example potassium hexacyanocobaitat, used. A water-miscible, heteroatom-containing organic compound which forms a complex with the precipitated salt is generally added immediately to the resulting suspension of precipitation. This connection can also already be present in one or in both educt solutions. These are mostly ethers, polyethers, alcohols, ketones or mixtures of these compounds. Such methods are described for example in US-A-3, 278, 457, US-A-3,278, 458, US-A-3, 278, 453 or EP-A-654,302.

Another method is described in DD-A-148,957. Zinc hexacyanoiridate is produced here by reacting zinc chloride with hexacyanoiridic acid, which was previously isolated as a solid and used in this form. A disadvantage of using zinc hexacyanoiridate is its color. The polyether alcohols produced using this catalyst are also colored yellow, which is perceived as a poor quality for many applications.

In the production of zinc hexacyanometalates using the corresponding hexacyanometalic acid, there is no accumulation of potassium chloride, the removal of which is expensive. For example, EP-A-283 148 describes a process for the preparation of double metal cyanide complex catalysts in which the alkali metal chloride formed is bound to filter aids. Inorganic substances, in particular aluminosilicates, are used as filter aids. However, the step of removing the alkali chloride is an additional process step and is therefore complex. The catalyst produced by this process shows properties comparable to those which are produced without the addition of filter aids.

The object of the invention was to provide multimetal cyanide complex catalysts which are simple to produce and have high catalytic activity.

The object of the invention was surprisingly achieved by a process for the preparation of multimetal cyanide catalysts in which a metal salt is reacted with a cyanometalic acid in the presence of solids which are inert to the reaction participants.

The invention accordingly relates to a process for the preparation of multimetal catalysts, characterized in that a) reacting a solution of a metal salt of the general formula M ¹ _m (X) n / where 3

M ^{1 is} a metal ion selected from the group containing Zn ²⁺ , Fe ²⁺ , Co ³⁺ , NL ²⁺ , Mn ⁺ , Co ²⁺ , Sn ^{2 ~} , Pb ²⁺ , Fe ³⁺ , Mo ⁴⁺ , Mo ^{β +} , AI ³ -, v ⁵⁺ , Sr ²⁺ , W ⁴⁺ , W ^{δ +} , Cu ²⁺ , Cr ²⁺ , Cr ³⁺ , Cd ² ",

X is an anion selected from the group consisting of halide, hydroxide, sulfate, carbonate, cyanide, thiocyanate, isocyanate, carboxylate, oxalate, nitrate, m and n are integers, corresponding to the valencies of M ¹ and X a solution of a cyanometalate compound of the general formula

H _a M ² (CN) _b (A) _c , where

M ^{2 is} a metal ion selected from the group ^comprising Fe ²⁺ , Fe ³⁺ , Co ^3τ , Cr ³⁺ , Mn ²⁺ , Mn ³⁺ , Rh ³ -, Ru ³⁺ , V ⁴⁺ , V ⁵⁺ , Ir ³⁺ , Co ² "and Cr ²⁺ , where M ^{2 may be the} same or different M ¹ , H is hydrogen,

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

and a, b and c are integers which are selected in such a way that the electroneutrality of the cyanometalate compound is ensured, at least one of the two solutions comprising at least one water-miscible, heteroatom-containing organic ligand selected from the group comprising alcohols, aldehydes, Can contain ketones, ethers, polyethers, esters, urea, amides, nitriles and sulfides and at least one of the two solutions contains at least one inert, inorganic or organic solid which is insoluble in the starting materials and end products,

b) associations of the aqueous suspension formed in step a) with at least one water-miscible ligand, selected from the group described in step a), which may be the same or different from the ligands in step a)

c) separating the double metal cyanide compound from the suspension.

M ¹ is preferably selected from the group containing Zn ²⁺ , Fe ²⁺ , Co ²⁺ and Ni ²⁺ , in particular Zn ²⁺ , X is preferably selected from the group containing carboxylate, halide, oxalate and nitrate, in particular carboxylate, M ² is preferably selected from the group comprising Co ²⁺ , Co ³⁺ , Fe ⁺ , Fe ³⁺ , Cr ³⁺ , Rh ³⁺ and Ir ³⁺ , in particular Co ³⁺ .

The preparation of the preferably used cyanometallic acid H _a M ² (CN) - _D (A) _C can be carried out, for example, as described in W. Klemm, W. Brandt, R. Hoppe, Z. Anorg. Ailg. Chem. 308, 179 (1961) 4 wrote, starting from alkali metal cyanometalate via the silicon cyanometalate to cyanometalate hydrogen acid. A further 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. All. Chem. 270, 45 (1952) or A. Ludi, HM Güdel, V. Dvorac, Helv. Chi. Acta 50, 2035 (1967). Further possibilities for the synthesis of the cyanometalate hydrogen acids can be found, for example, in "Handbook of Preparation Inorganic Chemistry, G. Bauer (Editor), Ferdinand Enke Verlag, Stuttgart, 1981. Synthesis of such compounds is the most advantageous route for the synthesis of ion exchangers.

The acids are stable in aqueous solution and keep well. They can be processed immediately after synthesis, but it is also possible to store them for a longer period. Storage should take place in the dark.

Water-miscible organic substances are used as ligands containing heteroatoms. Keteroatoms are understood to mean non-carbon atoms, in particular oxygen, nitrogen and sulfur.

Ligands which are preferably used are alcohols, aldehydes, ketones, ethers, polyethers, esters, polyesters, ureas, amides, nitriles and sulfides, particularly preferably alcohols, ketones, ethers, polyethers or mixtures thereof, in particular alcohols, ethers, polyethers and mixtures thereof.

The solids which are added according to the invention and which are inert towards the reaction participants in the catalyst synthesis can be both inorganic and organic.

Oxides, nitrides, carbides, inert metals or metal alloys are preferably used as inorganic substances. Oxides of metals from groups IIB to VIIIB and oxides of metals from groups IIIA and IVA and mixtures thereof can be used as oxides. Oxides of group III A, IV A, Illb, IVb to VIb, manganese oxides, iron oxides, cobalt oxides, nickel oxides and zinc oxide and mixtures thereof are particularly preferably used. Silicon nitride, boron nitride, vanadium nitride, chromium nitride or tungsten nitride can be used as nitrides. The covalent or metallic carbides are preferably used as carbides, for example silicon carbide, boron carbide, titanium, zirconium, hafnium, vanadium, niobium, tantalum, molybdenum or woifram carbide. 5

The inorganic solids are added either in the form of fine powder or as grit, fibers, fiber fabrics or moldings, such as balls, strands or stars. Powder, grit and fibers and fiber fabrics are preferred. The BET surface areas of the solids are preferably between 0.1 and 1000 m ² / g, particularly preferably between 1 and 900 m ² / g and in particular between 10 and 800 m ² / g.

Organic inert solids can be natural or synthetic polymers, but also graphite, carbon black, activated carbons and oxidatively treated activated carbons. Natural polymers include cellulose, keratins and water-insoluble pectins. Synthetic polymers are, for example, polyethylene, polypropylene, polystyrene, polyurethane, polycarbonate, polyacrylate, polymethacrylate, polyamide as well as polyether or polyester. Cellulose, polyurethanes and polyalkylenes are preferred. They are added in the form of powder, fibers, fiber fabrics, moldings, granules.

The inert solids are mostly used in 0.05 to 20 times the amount of the double metal cyanide to be precipitated. 0.1 to 10 times the amount is preferred, particularly preferably 0.2 to 5 times the amount.

In a preferred embodiment of the invention, an inorganic or in particular organic solid is used which is inert under the production conditions of the double metal cyanide salt, but which dissolves under the reaction conditions during the preparation of the polyetherol and remains in the polyetherol after the preparation, for example polyester.

To carry out the process according to the invention, an aqueous solution of a cyanometalate hydrogen acid is combined with the aqueous solution of a metal salt of the general formula M ¹ _m (x) _n , where the symbols have the meaning explained above. This is done in particular with a stoichiometric excess of the metal salt. 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 submit the solution of the cyanometalate hydrogen acid and to add the metal salt, but the procedure can also be reversed. Thorough mixing, for example by stirring, is required during and after the starting material solutions have been combined.

The content of the cyanometalate hydrogen acid in the solution is 0.1 to 30% by weight, preferably 1 to 20% by weight, and in particular 2 to 10% by weight, based on the reaction mixture. The 6

The content of the metal salt component in the solution is 1 to 50% by weight, preferably 2 to 40% by weight and in particular 5 to 30% by weight.

The inert solid is preferably added to the solution which is initially introduced and / or has the larger volume.

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. It is advantageous to add the ligands preferably to the cyanometalate-hydrogen acid solution due to the change in the salt solubilities.

The content of the ligands in the solution is preferably 1 to 60% by weight, particularly preferably 5 to 40% by weight and in particular 10 to 30% by weight.

After the addition of the ligands, the double metal cyanide complexes formed are separated from the aqueous phase. This can be done by the usual and known separation methods, for example by filtration or centrifugation.

The starting materials are preferably mixed at temperatures between 10 and 80 ° C., particularly preferably between 15 and 60 ° C. and in particular between 20 and 50 ° C.

The double metal cyanide complexes are then dried. Drying can take place at room temperature and normal pressure. Drying is preferably carried out at temperatures from 20 to 90 ° C. and pressures from 0.01 to 1 bar, in particular at temperatures from 20 to 70 ° C. and pressures from 0.05 to 0.7 bar.

After separation and drying, the double metal cyanide complexes can be treated again with the aqueous solution of the ligands or the pure ligands themselves, separated and dried.

The double metal cyanide complexes according to the invention are used in particular as catalysts in the production of polyetherols by polymerizing lower alkylene oxides, in particular ethylene oxide and / or propylene oxide with a low content of unsaturated constituents. 7

Compared to conventional double metal cyanide catalysts, the catalysts prepared by the process according to the invention have a significantly increased activity with extremely short light-off times of 1 to 20 minutes. It is therefore possible to work with catalyst concentrations of less than 250 ppm, preferably less than 150 ppm and particularly preferably less than 75 ppm, based on the weight of the polyether alcohol.

The invention is illustrated by the examples below.

Synthesis of double metal cyanide catalysts

example 1

200 ml of strongly acidic ion exchanger (K2431, Bayer) were regenerated twice with 90 g of 37% hydrochloric acid and washed with water until the process was neutral. A solution of 16.8 g of K ₃ [Co (CN) ₆ ] in 50 ml of water was then added to the exchange column. The column was then eluted until the outlet was neutral again. The Co: K ratio in the eluate obtained was greater than 10. The 372 g of eluate obtained were heated to 40 ° C. and 20.0 g of α-aluminum oxide were suspended therein. A solution of 20.0 g of zinc (II) acetate dihydrate in 70 g of water was then added with stirring. The suspension was stirred at 40 ° C. for a further 10 minutes, then 84 g of ethylene glycol dimethyl ether were added and the suspension was stirred at 40 ° C. for a further 30 minutes. The solid was then filtered off and washed on the filter with 300 ml of ethylene glycol dimethyl ether. The solid thus treated was dried at room temperature.

Example 2

200 ml of strongly acidic ion exchanger (K2431, Bayer) were regenerated twice with 90 g of 37% hydrochloric acid and washed with water until the process was neutral. A solution of 16.8 g of K ₃ [Co (CN) ₆ ] in 50 g of water was then added to the exchanger acid. The column was then eluted until the outlet was neutral again. The Co: K ratio in the eluate obtained was greater than 10. The 358g eluate obtained were heated to 40 ° C and 20g cellulose therein Techno Cell ^® were suspended 150th A solution of 20.0 g of zinc (II) acetate dihydrate in 70 g of water was added with stirring. The suspension was stirred at 40 ° C for a further 10 min. Then 84 g of ethylene glycol dimethyl ether were added and the suspension was stirred at 40 ° C. for a further 30 min. The resulting solid was suctioned off and placed on the filter with 300 ml 8th

Washed ethylene glycol dimethyl ether. The solid thus treated was dried at room temperature.

Example 3 5

400 ml of strongly acidic ion exchanger (K2431, Bayer) were regenerated twice with 180 g of 37% hydrochloric acid and washed with water until the process was neutral. A solution of 40.4 g of K [Co (CN) ₆ ] in 130 g of water was then added to the exchanger

10 shear column. The column was then eluted until the outlet was neutral again. The Co: K ratio in the eluate was greater than 10 obtained 733g 366,5g of the eluate obtained were heated to 40 ° C and 20g cellulose therein Techno Cell ^® were suspended 150th A solution of 20.0 g was added with stirring

15 zinc (II) acetate dihydrate added to 70 g of water. Then were

69.1g tert. -Butanol added and the suspension stirred at 40 ° C for a further 30 min. The solid was then filtered off and washed on the filter with 300 ml of ter-butanol. The solid thus treated was dried at room temperature.

20th

Example 4

400 ml of strongly acidic ion exchanger (K2431, Bayer) were regenerated twice with 180 g of 37% hydrochloric acid and with water

25 washed until the process was neutral. A solution of 40.4 g of K ₃ [Co (CN) g] in 130 g of water was then added to the exchange column. The column was then eluted until the outlet was neutral again. The Co: K ratio in the 772 g of eluate obtained was greater than 10. 386 g of the eluate obtained were

30 tempered 40 ° C and suspended in 2g of aluminum oxide fibers (ICI). A solution of 20.0 g of zinc (II) acetate dihydrate in 70 g of water was added with stirring. Then 69.1 g were tert. -Butanol added and the suspension stirred at 40 ° C for a further 30 min. The solid was then filtered off and on the

35 filters washed with 300ml tert-butanol. The solid thus treated was dried at room temperature. The content of double metal cyanide in the solid mixture was 90%.

Example 5

40

400 ml of strongly acidic ion exchanger (K2431, Bayer) were regenerated twice with 180 g of 37% hydrochloric acid and washed with water until the process was neutral. A solution of 4.0 g of K [Co (CN) ₆ l in 20 g of water was then added to the exchanger column. The column was then eluted until the outlet was neutral again. The Co: K ratio in the eluate obtained (490 g) was greater than 10. 245 g of the eluate obtained were at 40 ° C. 9 tempering _t and 18g therein alumina fibers (Fa. ICI) were suspended. A solution of 2.0 g of zinc (II) acetate dihydrate in 50 g of water was added with stirring. Then 69.1 g of _t -butanol were added and the suspension was aged for 30 minutes without stirring. The solid was then filtered off and tert with 300 ml on the filter. -Butanol washed. The thus treatable _t e solid was dried at room temperature. The content of _D oppelme _t allcyanid in the solid mixture was 10%.

_S ynthesis of polyether polyols

_I n the following examples was used as a starter oligopropylene obtained by alkali-catalyzed reaction of propylene oxide with _D ipropylenglykol at 105 ° C. This oligopropylene was measured using a magnesium silicate from a _K _t alysator free and had the following characteristics: hydroxyl number: 280 mg KOH / g; Unsaturated components: 0.003 meq / g, sodium and potassium content: less than 1 ppm.

Example 6

509 g of the oligopropylene glycol were mixed with 0.5 g of catalyst from Example 1 (corresponding to 100 ppm based on the finished product ⁾ in a stirred autoclave under a nitrogen atmosphere. _Fter evacuating the Kesseis were dosed 150g of propylene oxide at 105 ° C. The start of the reaction was recognized by the after 11 min. onset of a drop in pressure which, after the propylene oxide metering, is initially 2.8 bar abs. scam. After the completion of the propylene oxide breagieren _A further 1982g propylene oxide was added at the same temperature so that a pressure bar was not exceeded of 1.8. After 46min the dosing phase ended ^¬ was det.

_The polyetherol obtained was filtered once. It had a hydroxyl number of 55.7 mg KOH / g, a content of unsaturated Be ^¬ was share of 0.0099 meq / g, a zinc content of 6 ppm and a cobalt content of 3ppm.

Example 7

506g of the oligopropylene glycol were mixed with 0.5 g of catalyst from Example 2 (corresponding to 100 ppm based on the finished product) in a Rührau _t oklaven mixed under nitrogen atmosphere. _Fter evacuating the reactor were metered in 150g of propylene oxide at 105 ° C. The start of the reaction was recognized by the after 11 min. onset of a drop in pressure which, after the propylene oxide metering, is initially 2.8 bar abs. scam. After the full 10

A further 1970 g of propylene oxide were reacted at the same temperature in such a way that a pressure of 2.2 bar was not exceeded. The metering phase was ended after 42 minutes.

The polyetherol obtained was filtered once. It had a hydroxyl number of 54.4 mg KOE / g, an unsaturated content of 0.0101 meq / g, a zinc content of <1 ppm and a cobalt content of <1 ppm.

10

Example 8

511.9 g of the oligopropylene glycol were mixed with 0.694 g of catalyst from Example 4 (corresponding to 250 ppm DMC based on the finished

15 product) mixed in a stirred autoclave under a nitrogen atmosphere. After evacuating the kettle, 150 g of propylene oxide were metered in at 105 ° C. The pressure rose to 2.9 bar, which decreased slowly in the first 10 minutes and then steeply. After the steep pressure drop that started the reaction

20 shows, a further amount of 1837.6 g of propylene oxide was metered in without interruption within 90 min at the same temperature, the pressure being practically constant at 1.2 bar.

The polyetherol obtained was filtered once. It had a hydroxyl number of 56.3 mg KOH / g, an unsaturated component content of 0.0065 meq / g, a zinc content of 12 ppm and a cobalt content of 6 ppm. Gel permeation chromatography (GPC) was used to determine a number average molecular weight of 1800 g / mol, a weight average molecular weight of 1828 g / mol and a polydispersity of 1.016, the GPC being calibrated using commercial polypropylene glycol standards.

Example 9

35 511.9 g of the oligopropylene glycol were mixed with 0.278 g of catalyst from Example 4 (corresponding to 100 ppm DMC based on the finished product) in a stirred autoclave under a nitrogen atmosphere. After evacuating the kettle, 150 g of propylene oxide were metered in at 105 ° C. The pressure rose to 2.48

40 bar, which dropped to 1.6 bar in the first 30 minutes. After this pressure drop, which indicated a first, partial start of the reaction, a further amount of 1837.6 g of propylene oxide was metered in continuously over the course of 90 minutes at the same temperature. With the further propylene oxide dosing,

45 rapid, pressure increase to a maximum of 2.9 bar, then an equally significant pressure drop to a level of 1.1 to 1.2 bar, which then remained constant until the end of metering. This A second drop in pressure indicated that the reaction and catalyst had fully started.

The polyetherol obtained was filtered once. It had a 5 hydroxyl number of 56.4 mg KOH / g, an unsaturated component content of 0.0089 meq / g, a zinc content of 3 ppm and a cobalt content of 1 ppm. Gel permeation chromatography (GPC) was used to determine a number average molecular weight of 1802 g / mol, a weight average molecular weight of 2031 g / mol and a polydispersity of 1.127, the GPC being calibrated using commercial polypropylene glycol standards.

Example 10

15,513.6 g of the oligopropylene glycol were mixed with 2.5 g of catalyst from Example 5 (corresponding to 100 ppm DMC based on the finished product) in a stirred autoclave under a nitrogen atmosphere. After evacuating the kettle, 150 g of propylene oxide were metered in at 105 ° C. The pressure rose to 2.92

20 bar, which dropped to 1.44 bar in 10 minutes. After this drop in pressure, which indicated the start of the reaction, a further 1844.2 g of propylene oxide were metered in continuously over the course of 90 minutes at the same temperature. With the further propylene oxide dosing, there was initially a slow rise in pressure to a level

25 ximum of 1.86 bar, then an equally slow pressure drop to 1.3 bar. The pressure rose to 1.5 bar by the end of metering.

The polyetherol obtained was filtered once. It had a hydroxyl number of 56.8 mg KOH / g, an unsaturated component content of 0.0104 meq / g, a zinc content of 6 ppm and a cobalt content of 2 ppm. Gel permeation chromatography (GPC) was used to determine a number average molecular weight of 1807 g / mol, a weight average molecular weight of 1880 g / mol and a polydispersity of 1.040, the GPC being calibrated using commercial polypropylene glycol standards.

Example 11

40 511.8 g of the oligopropylene glycol were mixed with 0.5 g of catalyst from Example 3 (corresponding to 100 ppm DMC based on the finished product) in a stirred autoclave under a nitrogen atmosphere. After evacuating the kettle, 150 g of propylene oxide were metered in at 105 ° C. The pressure rose to 3.12

45 bar, which dropped slowly to 2.8 bar in the first 40 minutes, but dropped sharply to 0.7 bar in the following 13 minutes. The second steep drop in pressure indicated the start of the reaction. After that 12 a further 1837.2 g of propylene oxide were metered in without interruption within 90 min at the same temperature. As the propylene oxide was metered in further, the pressure initially rose to a maximum of 1.8 bar, followed by a slow pressure drop to 1.4 bar. The pressure rose to 1.5 bar by the end of metering.

The polyetherol obtained was filtered once. It had a hydroxyl number of 56.7 mg KOH / g, an unsaturated component content of 0.0085 meq / g, a zinc content of 5 ppm and a cobalt content of 2 ppm. Gel permeation chromatography (GPC) was used to determine a number average molecular weight of 1806 g / mol, a weight average molecular weight of 1857 g / mol and a polydispersity of 1.028, the GPC being calibrated using commercial polypropylene glycol standards.

Claims

13 Patent claims

1. Process for the preparation of double metal cyanide compounds

a) implementation of a solution of a metal salt of the general formula M ¹ _m (X) _n , where

M ^{1 is} a metal detail selected from the group comprising Zn ²⁺ , Fe ² ", Co ³⁺ , Ni ²⁺ , Mn ⁺ , Co ²⁺ , Sn ^{2 ~} , Pb ^2τ , Fe ^{3 ~} , Mo ⁺ ,

Mo ⁶⁺ , Al ³⁺ , V ⁵ -, Sr ²⁺ , W ⁺ , W ⁶⁺ , Cu ² ", Cr ²⁺ , Cr ⁺ , Cd ²⁺ X an anion selected from the group containing halide, hydroxide , Sulfate, carbonate, cyanide, thiocyanate, isocyanate, carboxylate, oxalate, nitrate mean, m and n are integers, corresponding to the valencies of M ¹ and X, with a cyanometalate compound of the general formula H _a M ² (CN) _b (A) _c , where M ^{2 is} a metal ion selected from the group containing Fe ²⁺ , Fe ³⁺ , Co ^{3 +} , Cr ³⁺ , MrJ ⁺ , Mn ³⁺ , Rh ³ ", Ru ³ ", V ^4τ , V ⁵⁺ ,

Ir ³ ", Co ²⁺ and Cr ^{2 ~} , where M ^{2 can be} identical or different M ¹ ,

K hydrogen,

A is an anion selected from the group comprising halide, hydroxide, sulfate, carbonate, cyanate, thiocyanate,

Isocyanate, carboxylate, nitrate or cyanide means a, b and c are integers which are selected so that the electroneutrality of the cyanometalate compound is ensured, at least one of the two solutions being selected from at least one water-miscible organic ligand containing heteroatoms the group containing alcohols, aldehydes, ketones, ethers, polyethers, esters, urea, amides, nitriles and sulfides,

b) combinations of the aqueous suspension formed in step a) with at least one water-miscible ligand, selected from the group described in step a), which may be the same or different from the ligand used in step a),

c) separating the double metal cyanide compound from the suspension, 14 characterized in that at least one of the educt solutions used in step a) contains at least one inert inorganic or organic solid which is insoluble in the educts and end products.

2. The method according to claim 1, characterized in that the solid is selected from the group comprising metals, metal alloys, metal oxides, metal nitrides and metal carbides.

3. The method according to claim 1, characterized in that the solid is an organic polymer.

4. The method according to any one of claims 1 to 3, characterized in that the amount of solid is 0.05 to 20 times the weight of the double metal cyanide compound.

5. Double metal cyanide compounds, producible according to one of claims 1 to 4.

6. Use of double metal cyanide compounds according to claim 5 as catalysts for the polymerization of alkylene oxides.