MXPA05012597A - Nano-scale dmc catalyst particles - Google Patents

Abstract

Nano-scale DMC catalyst complexes are highly active alkylene oxide polymerization catalysts. Thy show a greatly improved ability to catalyze the formation of EO-capping onto secondary hydroxyl-terminated polyethers. The catalysts can be prepared by precipitation in the dispersed adequous phase of a water-in-oil emulsion.

Description

DMC CATALYTIC PARTICLES AT NANOMETRIC SCALE This invention relates to methods for forming metal cyanide catalyst complexes, and to methods for polymerizing alkylene oxides, in the presence of a metal cyanide catalyst. Polyethers are prepared in large commercial quantities by the polymerization of alkylene oxides, such as propylene oxide and ethylene oxide. This polymerization reaction is usually carried out in the presence of an initiator compound and a catalyst. The initiator compound usually determines the functionality (the number of hydroxyl groups per molecule of the polymer) and in some cases, imparts some desired functionality. The catalyst is used to provide an economical rate of polymerization. Metal cyanide complexes are becoming increasingly important as catalysts for alkylene oxide polymerization. These complexes are often referred to as "double metal cyanide" or "DMC" catalysts (acronyms for their English designation: Double Metal Cyanide), and are the subject of several patents including, for example, U.S. Patent Nos. 3,278,457, 3,278,458 , 3,278,459, 3,404,109, 3,427,256, 3,427,334, 3,427,335 and 5,470,813, among many others In some cases, these complexes provide the benefit of rapid polymerization and polydispersity rates restricted. Additionally, these catalysts are associated with the production of polyethers having very low levels of unsaturated monofunctional compounds. A drawback of conventional DMC catalysts is their inability to efficiently polymerize poly (ethylene oxide) endcaps in poly (propylene oxide) polyols to form polyols terminated with primary hydroxyl groups.The highest reactivity of the primary hydroxyl groups (together with increased hydrophilicity), make the OE-coated polyols particularly useful for forming flexible polyurethane foam and polyurethanes and polyurethane-ureas molded by reaction-injection (RIM, acronym for its English designation: Reaction Injection Molded). Anionic polymerization, conventional, such as alkali metal hydroxides and alkaline earth metal hydroxides polymerize very efficiently the ethylene oxide at the ends of the poly (propylene oxide) chain to form crowned poly (oxyethylene) polyols with OE. This aspect allows the polyols crowned with OE to be p carried out in a single polymerization process, sequentially polymerizing propylene oxide and then ethylene oxide in the presence of the catalyst. When this is attempted using DMC catalysts, most of the ethylene oxide tends to form poly (very high molecular weight) ethylene oxide, instead of forming the desired end crowns.The result is a mixture of a poly (oxide) homopolymer of propylene) (OP) with a small proportion of a high molecular weight poly (ethylene oxide) (EO) homopolymer. The terminal groups of the poly (OP) are almost exclusively secondary hydroxyl. The difficulty of forming OE coronations increases with increasing molecular weight of the poly (OP) polymer. No effective method has been developed for poly (OP) polymers crowned with EO, of a molecular weight greater than about 1,000. Thus, it would be convenient to provide a DMC catalyst that catalyses the coronation reaction with EO more efficiently. It would also be convenient to provide a DMC catalyst that efficiently polymerizes the propylene oxide as well. In one aspect, this invention is a metal cyanide catalyst in the form of particles, having an average particle size, as determined by means of transmission electron spectroscopy, of from about 20 to about 500 nm. In a second aspect, this invention is a process for forming a metal cyanide catalyst comprising: (A) forming an emulsion having a plurality of water droplets dispersed in an immiscible continuous phase; wherein the water droplets contain a cyanide compound of a transition metal and a metal salt which reacts with the transition metal cyanide compound, to form a water insoluble metal cyanide catalyst; and (B) subjecting the emulsion to such conditions that the compound of Transition metal cyanide and the metal salt react in the water droplets to form the water soluble metal cyanide catalyst. In a third aspect, the present invention is a process for preparing a metal cyanide catalyst comprising: (A) forming a first emulsion of first droplets of water dispersed in an immiscible continuous phase, wherein the first drops of water contain a compound of transition metal cyanide; (B) forming a second emulsion of second drops of water dispersed in an immiscible continuous phase; wherein the second water droplets contain a dissolved metal salt which reacts with the transition metal cyanide compound to form a water insoluble metal cyanide catalyst; (C) mixing the first and second emulsions under conditions such that said first drops of water make contact with the second drops of water; and (D) subjecting the resulting mixture to such conditions that the transition metal cyanide compound and the metal salt react in the water droplets to form the water-soluble metal cyanide catalyst. In a fourth aspect, this invention is a process in which a metal cyanide catalyst, in the form of a particles having an average particle size, as determined by transmission electron spectroscopy, from about 20 to about 300 nm, with an alkylene oxide; and the resulting mixture is subjected to conditions including an elevated temperature, sufficient to polymerize the alkylene oxide to form a polyalkylene oxide. In a fifth aspect, this invention is a process in which a poly (propylene oxide) polymer, which comprises contacting the poly (propylene oxide) polymer with ethylene oxide, is crowned with EO under polymerization conditions. , in the presence of a catalytically effective amount of a metal cyanide catalyst, in the form of particles having an average particle size, when determined by transmission electron spectroscopy, from about 20 to about 500 nm. In still another aspect, this invention is a process in which a metal cyanide catalyst is mixed with an alkylene oxide, and the resulting mixture is subjected to conditions including an elevated temperature, sufficient to polymerize the alkylene oxide to form a poly (alkylene oxide); wherein the metal cyanide catalyst is the product of a process comprising: (A) forming an emulsion having a plurality of water droplets dispersed in an immiscible continuous phase; where the water droplets contain a metal cyanide compound of transition and a metal salt that reacts with the transition metal cyanide compound to form a water insoluble metal cyanide catalyst; and (B) subjecting the emulsion to such conditions, that the transition metal cyanide compound and the metal salt react in the water droplets to form the water soluble metal cyanide catalyst. In still another aspect, this invention is a process in which a metal cyanide catalyst is mixed with an alkylene oxide, and the resulting mixture is subjected to conditions including an elevated temperature, sufficient to polymerize the alkylene oxide to form a poly (alkylene oxide); wherein the metal cyanide catalyst is the product of a process comprising: (A) forming a first emulsion of first droplets of water dispersed in an immiscible continuous seam; where the first drops of water contain a transition metal cyanide compound; (B) forming a second emulsion of second drops of water dispersed in an immiscible continuous phase; wherein the second water droplets contain a dissolved metal salt which reacts with the transition metal cyanide compound to form a water insoluble metal cyanide catalyst. (C) Mix the first and second emulsions under conditions such, that the first drops of water make contact with the second drops of water; and (D) subjecting the resulting mixture to conditions such that the transition metal cyanide compound and the metal salt react in the water droplets to form the metal cyanide catalyst, soluble in water. The DMC catalyst complex of the invention includes a water insoluble salt, generally complexed with water and, optionally, with an organic complexing agent. The water insoluble salt is a salt of an anionic radical consisting of a transition metal ion that coordinates with the cyanide (CN-) and, optionally, other coordination groups; and a metal cation (hereinafter referred to as "M"), which forms a salt insoluble in water with the anionic radical. The anionic radical can be represented as M1 (CN) r (X) t, where M1 is the ion of the transition metal, X is a coordination group different from cyanide, yryt are numbers representing the number of CN- and X groups , respectively, that are coordinated with the M1 ion. Generally, r is at least 4, preferably 5 and, more preferably, 6; and t is generally not greater than 2, preferably not greater than 1 and, most preferably, zero. Usually r + t will be equal to 6. M1 is preferably Fe + 3, Fe + 2, Co + 3, Co + 2, Cr + 2, Cr + 3, Mn + 2, Mn + 3, Ir3, Ni + 2, Rh + 3, Ru + 2, V + 4 or V + 5. Among the above, the transition metals in the oxidation state plus three are preferred. Still more preferred are Co + 3 and Fe + 3, and most preferred is Co + 3. The radical Anionic that is most preferred is Co (CN) 63. The metal cation is preferably a metal ion selected from the group consisting of Zn + 2, Fe + 2, Co + 2, Ni + 2, Mo + 4, Mo + 6, Al + 3, V + 4, V + 5, Sr + ¿, W + 4, W + b, Mn + 2, Sn + 2, Sn + 4, Pb + ¿, Cu + 2, La. + 3 and CR . It is preferred that M be Zn, Fe, Co, Ni, La, + 3 Cr + 3. What is most preferred is that M is Zn + 2. A mixture of metal ions can be used. The metal cation is generally present in a stoichiometric excess, relative to the amount of anionic radical; that is, the metal cation and the anionic radical do not, by themselves, form an electrostatically neutral salt. It is preferred that the insoluble salt contains about 2 to 4, in particular about 3 to 4, metal atoms per transition metal atom supplied by the anionic radical. Because the metal atom and the anionic radical do not form an electrostatically neutral salt, additional anions are present in the water insoluble salt. At least some of those anions are anions that do not contain a transition metal atom. Additional preferred anions include halides (especially chloride and bromide), sulfate, nitrate, hydroxide and the like. The water-insoluble salt can also contain a proportion of anions having the structure M2 (X) 6) where M2 is defined in the same way as M1 and X is as defined above. Preferred X groups include anions such as halide (in chloride), hydroxide, sulfate, carbonate, oxalate, thiocyanate, isocyanate, isothiocyanate, carboxylate of 1 to 4 carbon atoms and nitrite (NO2-), and uncharged species, such as CO, H2O and NO. Particularly preferred X groups are NO, NO2- and CO. Thus, the water insoluble salt can be represented by the formula: Mb [m1 (CN) r (x) t] c [M2 (X) 6] d Ae (I) where b, c, d and e represent numbers that they reflect an electrostatically neutral salt. Sometimes the formula of water-insoluble salts, of this type, has been represented in a form such as: Mb [M1 (CN) r (X) t] c [M2 (X) 6] d-nMxAy (II) where b, c and d represent numbers that together reflect an electrostatically neutral salt; n represents the relative number of groups MxAy, andxy "and" are numbers that reflect an electrostatically neutral salt of M and A. For the purposes of the invention, the representations (I) and (II) are considered equivalent, and are not considered that represent the particular arrangement of atoms and radicals in space. Both b and c and e are positive numbers. In turn, d is zero or a positive number, and preferably is zero. The number of atoms M is preferably about 2 to 4, in particular about 3 to 4 times the number of the total of the atoms of M and M2. The water insoluble salt optionally is complexed with one or more organic complexing agents.

Complexing agents that are useful in DMC catalyst complexes are well known and include, for example: alcohols, aldehydes, ketones, ethers, amides, nitriles, sulfides, sulfones, sulfoxides and the like. Suitable alcohols include monoalcohols and polyalcohols. Monoalcohols include: methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tertbutanol, octanol, octadecanol, 3-butyn-1-ol, 3-buten-1-ol, propargyl alcohol, 2-methyl-2 -propanol, 2-methyl-3-butin-2-ol, 2-methyl-3-buten-2-ol, 3-butin-1-ol, 3-buten-1-ol, 1-terbutoxy-2-propanol and similar. Suitable monoalcohols also include halogenated alcohols, such as 2-chloroethanol, 2-bromoethanol, 2-chloro-1-propanol, 3-chloro-1-propanol, 3-bromo-1-propanol, 1,3-dichloro-2- propanol, 1-chloro-2-methyl-2-propane, as well as nitro alcohols, ketoalcohols, ester-alcohols, cyanoalcohols and other inertly substituted alcohols. Suitable polyalcohols include: ethylene glycol, propylene glycol, glycerin, 1,1-trimethylolpropane, 1,1,1-trimethylolethane, 1,2,3-trihydroxybutane, pentaerythritol, xylitol, arabitol, mannitol, 2,5-dimethyl-3. -hexin-2,5-diol, 2,4,7,9-tetramethyl-5-decin-4,7-diol, sucrose, sorbitol, alkyl glucosides, such as methylglucoside and ethylglucoside, and the like. Polyether polyols of low molecular weight, in particular those having an equivalent weight of about 350 or less, more preferably about 125 to 250, are also useful complexing agents. Suitable aldehydes include: formaldehyde, acetaldehyde, butyraldehyde, valeric aldehyde, glyoxal, benzaldehyde, thalic aldehyde and the like. Suitable ketones include: acetone, methyl ethyl ketone, 3-pentanone, 2-hexanone and the like. Suitable ethers include: cyclic ethers, such as dioxane, trioxymethylene and paraformaldehyde, as well as acyclic ethers, such as diethyl ether, 1-ethoxypentane, bis (beta-chloroethyl) ether, methylpropyl ether, diethoxymethane, dialkyl ethers of alkylene glycols or polyalkylene glycols ( such as ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether and octaethylene glycol dimethyl ether), and the like. Amides, such as formamide, acetamide, propionamide, butyramide and valeramide are useful complexing agents. Esters, such as amyl formate, ethyl formate, hexyl formate, propyl formate, ethyl acetate, methyl acetate, triethylene glycol diacetate and the like, may also be used. Suitable nitriles include: acetonitrile, propionitrile, and the like. Suitable sulfides include: dimethyl sulfide, diethyl sulfide, dibutyl sulfide, diamyl sulfide and the like. Suitable sulfones and sulfoxides include: dimethyl sulfoxide, tetramethylene sulfoxide, 2,2-sulfonyldiethanol, dimethylsulfone and sulfolane (tetramethylene sulfone). The preferred complexing agents are: terbutanol, 1,2-dimethoxyethane (glyme), 1-terbutoxy-2-propane, polyether polyols having an equivalent weight of about 75 to 350 and dialkyl ethers of alkylene glycols and polyalkylene glycols. Particularly preferred complexing agents are terbutanol, glyme, 1-terbutoxy-2-propanol, polyether polyols having an equivalent weight of 125 to 250, and a dimethyl ether of mono-, di- or triethylene glycol. Terbutanol and glyme are especially preferred. The DMC catalyst complex is in the form of particles having an average particle size of about 5 to 500 nanometers, when determined by transmission electron spectroscopy, before exposing the catalyst to an alkylene oxide for polymerization. Preferably the particles have an average particle size, by volume, of about 10 nanometers, such as about 40 nanometers to 300 nanometers; more preferable, up to about 250 nanometers, especially up to about 200 nanometers; very preferable, up to about 150 nanometers. The DMC catalyst complex can be prepared at said small particle sizes by precipitating it in the dispersed aqueous ase of a water-in-oil emulsion. In this method, water-soluble or water-miscible precursor materials are combined and subjected to reaction conditions within aqueous droplets in the emulsion. The catalyst complex forms and precipitates as very fine particles within the droplets.

The precursor materials include a water soluble or water dispersible salt of the metal M, and a transition metal cyanide compound. The salt of M is in the form MxAy; where M, x, A and "y" are as defined above. Preferably the transition metal cyanide compound has the formula: Bw [M1 (CN) r (X).], Where B represents hydrogen, an ammonium cation or an alkali metal ion, and w is the absolute value of the valence of the group M1 (CN) r (X) t. It is preferred that B is not an alkali metal, since the alkali metal by-products that are formed in the reaction tend to inactivate the catalyst and, therefore, must be removed. Preferably, B is hydrogen. In a preferred embodiment, an aqueous solution of the M salt is prepared and formed into a water-in-oil emulsion, mixing the solution with one or more surfactants and an organic liquid which is immiscible with the aqueous solution. This is preferably effected by first mixing the salt solution with the surfactants, and then dispersing this mixture with stirring in the organic phase. The conditions are selected in such a way that the aqueous phase forms droplets of approximately 500 nm or less in diameter. The aqueous phase may constitute about 0.5 to 60 percent or more of the total weight of the emulsion, as long as the emulsion is stable and the droplets have the desired size. In the preferred embodiment, a solution or a dispersion of the transition metal cyanide compound, and formed separately to a water-in-oil emulsion, in a similar manner. The preferred droplet sizes and the preferred aqueous phase contents are the same as for the emulsion of the M. salt solution. The separated solutions are then mixed, under conditions in which the M salt and the transition metal cyanide within the dispersed water droplets, to form the DMC catalyst complex. In general, the reaction proceeds well at temperatures above 0 ° C and up to 100 ° C or more; but in general it is not necessary to heat or cool the mixture with respect to room temperature (15 to 30 ° C). Stirring is continued until: (1) the small drop size is maintained throughout the reaction; and (2) the collision of the droplets of the salt solution M and the solution or dispersion of the transition metal cyanide compound is promoted, so that the reactants make contact with each other and react. The time needed to complete the reaction depends on the reagents and the particular conditions, and can take from a few minutes up to twenty hours or more. It is preferred to provide about 2 to 4, especially about 3 to 4, moles of M atoms per mole of transmission metal atoms (ie, the atoms of M1 and M2). Consequently, the concentrations of the M salt and the metal cyanide compound are preferably selected. of transition in the starting solution, and the relative volumes of the initial aqueous phases, in order to obtain this. It is preferred that the droplet sizes of the starting emulsions are similar to each other, so that the average droplet size of one of the emulsions is not more than about five times, more preferably, not more than about twice, especially , not more than about 1.5 times the size of the other starting emulsion. It is also preferred that the volumes of the dispersed aqueous phases of the starting emulsions are similar to each other, so that the volume of the aqueous phase of one of the emulsions is not greater than about 5 times, preferably not greater than about of 2 times, especially not greater than about 1.5 times that of the other starting emulsion. By having similar droplet sizes and aqueous phase volumes, complete reaction, maintenance of the desired small droplet size and formation of desired particles of the small particle size catalyst complex are facilitated. The complexing agent, if it is used, it is conveniently added to the aqueous phase of one of the starting emulsions or both, preferably both starting emulsions. The complexing agent can be, for example, from zero to about 70 percent, preferably about 10 to 50 percent, of the combined weight of the water and the complexing agent in each of the aqueous phases.

However, it is possible to wash the catalyst with the complexing agent after it has precipitated and has been recovered. The organic phase of the emulsion is one or more organic compounds that are liquid at the temperatures used and that are substantially immiscible with water. At the temperatures used, the water of preference is soluble in the organic compounds, to a degree no greater than about 5 percent, preferably no greater than about 1 percent (w / w). The salt M and the transition metal cyanide compound must also be significantly more soluble in the aqueous phase than in the organic phase, so that it does not significantly migrate to the organic phase. If a complexing agent is present in the aqueous phase, the complexing agent must also exhibit relatively less miscibility with the organic phase than with the aqueous phase. Examples of suitable organic phase materials include hydrocarbons and alkanols of six or more carbon atoms, having boiling temperatures of at least about 50 ° C. Suitable hydrocarbons can be linear, alicyclic, aromatic, aromatic or alicyclic alkyl substituted compounds. Specific examples of suitable hydrocarbons include: petroleum ether, toluene, benzene, hexane, heptane, isooctane, hexanol, decanol, octanol and the like. The droplets of the aqueous phase are stabilized by means of at least one surfactant. Nonionic surfacta such as poly (oxyethylene ethers of alkylphenols or dialkylphenols, are particularly suitable. Examples thereof include the poly (oxyethylene) ethers of nonylphenol or octylphenol, such as nonylphenolic ether of poly (oxyethylene) 5 and octylphenolic ether of poly (oxyethylene) 9. Nonionic silicone surfactamay also be used. Anionic and cationic surfactacan also be used. Sufficient surfactant is used to stabilize the droplets of the aqueous phase, to the desired drop size. After the DMC catalyst complex precipitates, it can be converted by solid-liquid separation techniques, such as filtration and centrifugation. A preferred recovery method is to break the emulsion by adding a polar organic compound in which both the water and the organic phase are miscible, and then separating the catalyst complex particles by centrifugation. It is also preferred to wash the recovered particles one or more times with water or with a volatile polar organic compound (such as ethanol, acetone, dimethyl ether, low molecular weight polyethers, monoalkyl or dialkyl ethers of ethylene glycol or polyethylene glycol, and the like), in order to remove the residual surfactant and the residual organic phase materials. The recovered particles are also preferably dried to remove residual volatiles, such as excess water, excess complexing age washing compounds and the like. Preferably, drying is carried out under vacuum and under reduced pressure.

The particles can be dispersed in a polyether and / or in an initiator compound to form a suspension, which is removed to remove residual volatiles. The catalyst complex of the invention is useful for polymerizing alkylene oxides to form polyethers. In general, the process includes mixing a catalytically effective amount of the catalyst with an alkylene oxide, under polymerization conditions, and allowing the polymerization to proceed until the alkylene oxide supply is essentially depleted. The catalyst concentration is selected to polymerize the alkylene oxide at a desired rate or within a desired period of time. The amount of catalyst is sufficient to provide about 5 to about 100,000 parts by weight of metal cyanide catalyst complex per million parts by weight of alkylene oxide and initiator and comonomers, if present. A more preferred level of catalyst is about 20, especially about 30 to about 50,000, more preferably up to about 10,000 ppm.; still more preferable, up to about 1,500 ppm. Among the alkylene oxides which can be polymerized with the catalyst complex of the invention are ethylene oxide, propylene oxide, 1,2-butylene oxide, styrene oxide, epichlorohydrin and mixtures thereof. They can be polymerized sequentially various alkylene oxides to form block copolymers. More preferably, the alkylene oxide is propylene oxide or a mixture of propylene oxide and ethylene oxide and / or butylene oxide. Especially preferred are propylene oxide alone or a mixture of at least 70 weight percent, especially up to 85 weight percent, of propylene oxide; and up to about 30 percent, especially 15 percent by weight, of ethylene oxide. In addition, the monomers that will be copolymerized with the alkylene oxide in the presence of the catalyst complex can be used to prepare modified polyether polyols. Such comonomers include oxetanes, such as those described in U.S. Patent Nos. 3,278,457 and 3,404,109, and anhydrides such as those described in U.S. Patent Nos. 5,145,883 and 3,538,043, which produce polyester or polyether ester polyethers or polyols, respectively. Hydroxyalkanoates, such as lactic acid, 3-hydroxybutyrate, 3-hydroxyvalerate (and their dimers), lactones and carbon dioxide are examples of other suitable monomers that can be polymerized with the catalyst of the invention. Of particular interest are two polymerizations. The first of these is the polymerization of ethylene oxide to a poly (propylene oxide) homopolymer or copolymer having mainly terminal secondary hydroxyl groups. It has been found that the catalyst complex of the invention will cause that the ethylene oxide polymerizes on a surprisingly high proportion of those terminal secondary hydroxyl groups, to provide a polyol topped with EO, with a significant proportion of primary hydroxyls. The proportion of end groups that are crowned with EO tends to decrease as the molecular weight of the poly (propylene oxide) starting material increases For those starting materials with molecular weight of about 1500 or less, preliminary work has shown that more than 45 percent, in some cases more than 50 percent, of the extreme groups, can be crowned with EO, using the catalyst of the invention.For starting materials with molecular weight of about 1,500 to 3,000, it has been crowned with OE from 33 to 50 percent of the end groups, using the catalyst of the invention For starting materials with molecular weight of approximately 3,000 to 4,000 OE coronation of about 20 to 43 percent of the groups has been obtained It is expected that the optimized polymerization and optimized catalyst preparation methods will further increase the proportion of the end groups, which are crowned n OE, using the catalysts of the invention. The second type of polymerization of particular interest is the sequential polymerization of propylene oxide (or its mixtures with up to about 50 percent ethylene oxide), followed by a polymerization of ethylene oxide using the same catalyst, to form copolymers of blocks. The efficiencies in The coronation with EO, obtained, are similar to those described in the preceding paragraph. The polymerization reaction proceeds typically at temperatures of about 25 to 150 ° C or more, preferably about 80 to 130 ° C. A convenient polymerization technique involves loading the catalyst into a reactor and pressurizing the reactor with the alkylene oxide. An initiator or polyether compound is generally added, prior to the introduction of the monomers, and as discussed above, is typically combined with the catalyst complex prior to the formation of a catalyst suspension. The polymerization proceeds after a brief induction period, as indicated by a pressure loss in the reactor. The induction periods frequently approach zero with the catalyst of this invention. Once the polymerization has begun, additional alkylene oxide is conveniently fed to the reactor, on demand, until enough alkylene oxide has been added to produce a polymer with the desired equivalent weight. Another convenient polymerization technique is a continuous method. In such continuous processes the catalyst is continuously fed to a continuous reactor, such as a continuously stirred tank reactor (CSTR, acronym for its English designation: Continuously Stirred Tank Reactor) or a tubular reactor (usually as a suspension in the reactor). initiator and / or polyether). A feed of alkylene oxide is introduced into the reactor and continuously remove the product. The initiator can be added continuously or intermittently with the catalyst (such as in the form of a catalyst suspension in the initiator) or as a separate stream. Catalysts that exhibit a particularly short induction period, such as less than 15 minutes, preferably less than 10 minutes and especially less than five minutes, are particularly suitable for use in processes in which the catalyst is continuously added. The polymer produced can have different uses, depending on its molecular weight, its equivalent weight, its functionality and the presence of any functional group. The polyether polyols made in this way are useful as a raw material for forming polyurethanes. Polyethers can also be used as surfactants, hydraulic fluids, as a raw material for forming surfactants and as starting materials for the formation of aminated polyethers, among other uses. The following examples are given for illustrating the invention, but should not be construed as limiting its scope. All parts and percentages are by weight, unless otherwise indicated. The catalyst loads are calculated from the starting materials, ignoring any water and any associated initiators.

EXAMPLES 1 TO 16 Master solution A is prepared by mixing zinc chloride and water in a 1: 2 ratio by weight, with stirring, until the salt dissolves. Master solution B is prepared by mixing K2Co (CN) 6 and water. The mixture is stirred until the salt is dissolved and a 37 percent solution of hydrochloric acid is added over 10 minutes. The proportions of the components are: 1: 3: 3 (K2Co (CN) 6: water, HCl solution The mixture is cooled in an ice bath, a white precipitate (KCl) is formed and separated by filtration. The resulting solution contains approximately 10.6% of H3Co (CN) 6 by weight, Master solution C is prepared by mixing poly (oxyethylene) 5, nonylphenolic ether (Igepal® CO-520, surfactant) and octylphenyl ether of poly (oxyethylene). (Igepal® CO-630, surfactant) at a ratio of 2: 1 by weight The DMC catalyst of Example 1 is prepared in the following manner: 27 parts by weight of master solution A are diluted with 19 parts of water. they dilute 33.9 parts by weight of the master solution B with 12.1 parts of water, add 16 parts by weight of master solution C to each of the diluted solutions, with shaking, then add 28 parts by weight of petroleum ether to each one of the diluted solutions, followed by shaking.Each diluted solution f Orma an emulsion of water in oil, the size of the droplets of the dispersed phase being estimated in less than 500 nm. The diluted solutions are then mixed at room temperature and shaken at room temperature for 17 hours. The proportions of the starting materials provide about 4 moles of zinc atoms per mole of cobalt atom. The mixed solutions retain the form of a water-in-oil emulsion, with small droplet size. Precipitate a zinc hexacyanocobalatate catalyst complex, solid, with the droplets of the aqueous phase dispersed. The precipitated catalyst particles are recovered by adding about 320 parts by weight of ethanol, shaking until a homogeneous mixture forms (different from the dispersed solids), and centrifuged at 2,800 rpm for 30 minutes. The liquid phase is decanted and the particles are washed with ethanol and centrifuged three more times. The resulting particles are then dried under vacuum at 90 ° C for 24 hours. The DMC catalyst of Example 2 is prepared in the same manner, except that 10 g of ethanol is added to each of the diluted solutions, before adding the master solution C and the petroleum ether. The DMC catalyst of Example 3 is prepared in the same manner as that of Example 1, except that 10 g of 2-methyl-2-propanol are added to each of the diluted solutions, before adding master solution C and Petroleum ether. The DMC catalyst of Example 4 thereof is prepared Example 1, except that 10 g of ethylene glycol dimethyl ether (glyme) is added to each of the diluted solutions before adding the master solution C and the petroleum ether. The DMC catalysts of examples 5 to 8 are prepared in the same manner as those of examples 1 to 4, respectively, except that 43 parts by weight of master solution B are diluted with 3 parts by weight of water. In Examples 5 to 8 the proportions of starting materials provide about three moles of zinc atoms per mole of cobalt atoms. The DMC catalysts of Examples 9 are prepared 12 in the same manner as those of Examples 1 to 4, respectively, except that the recovered catalyst particles (before drying) are dispersed in a poly (propylene oxide) triol of molecular weight 700 (Voranol® 2070 polyol) , from Dow Chemical) to form a suspension containing about 6 percent dispersed catalyst particles. The resulting suspension is dried under vacuum at 50 ° C. Samples of the particles are taken before decomposing the emulsion (by the addition of ethanol) and after all the washes with ethanol are completed. The size of the particles is measured using transmission electron spectrometry (TEM), and found to be as follows: TABLE 1 The DMC catalysts of Examples 13 to 16 are prepared in the same manner as those of Examples 1 to 4, respectively, except that the recovered catalyst particles (before drying) are dispersed in a polypropylene oxide triol. with molecular weight 4,000 (Voranol® CP 4155 polio from Dow Chemical) to form a suspension containing about 6 percent dispersed catalyst particles. Again the resulting suspension is dried under vacuum at 50 ° C.

EXAMPLE 17 Each of the DMC catalysts of Examples 1 to 16 is discriminated by their activity to catalyze the polymerization of propylene oxide. Discrimination is carried out by adding a mixture of Voranol® 2070 polyol, propylene oxide and catalyst, to a Wheaton ampoule, equipped with a stir bar. The catalyst concentration is approximately 5,000 ppm, based on the weight of the starting materials. The contents of the Wheaton ampoule with agitation, at 90 ° C, until polymerization of the propylene oxide has occurred (as observed by visual inspection of the ampoule). All catalysts are active for the polymerization of propylene oxide. The DMC catalyst of Example 9 is evaluated in a series of polymerization reactions (17A-17I) to evaluate its ability to polymerize propylene oxide and to catalyze coronation reactions with EO. Polymerization reactions are carried out in the following manner: The DMC catalyst of Example 9 is mixed with additional Voranol® 2070 polyol, to provide sufficient catalyst to provide a catalyst level of approximately 1000 ppm in the polymer produced. The NMR analysis of the starting Voranol® 2070 polyol shows that it has an approximate Mn of 681.5 and an average degree of polymerization propylene oxide of about 10.2. About 70 g of the mixture is charged to a stirred Parr pressure vessel, and the vessel is pressurized with nitrogen to 100 psig. The reaction mixture is heated to 110 ° C and a measured amount of propylene oxide is added. The reaction of propylene oxide starts almost immediately, which indicates that the catalyst has a very short induction period or does not have any, before it is activated. When the polymerization of the propylene oxide is completed (as indicated by a constant reactor pressure), 30 mL of ethylene. Again an immediate and rapid polymerization of ethylene oxide occurs. The reaction is continued until all the ethylene oxide has reacted, which is indicated because the reactor reaches a constant pressure. The resulting polymers are opaque. The degree of polymerization of poly (ethylene oxide), the degree of polymerization of poly (ethylene oxide), the primary hydroxyl groups and the secondary hydroxyl groups are recovered and analyzed in terms of molecular weight (Mn), by NMR . The results are summarized in the following Table 2.

TABLE 2 The data in Table 2 illustrates that the catalyst actively polymerizes both the propylene oxide and the oxide of ethylene. A surprisingly high proportion of the end groups of the polyol produced are primarily hydroxyl, in particular when the molecular weight of the product is less than about 3,000 (up to about 2.714, before the addition of EO). These data indicate that a significant proportion of the ethylene oxide forms terminal OE crowns on the previously formed poly (propylene oxide) polymer, instead of forming high molecular weight poly (ethylene oxide) homopolymers. from Examples 10 to 12 in a manner similar to Experiment 17C, to produce a poly (propylene oxide) capped with OE of about 1500 Mn. The catalyst of Example 10 produces a polymer in which approximately 48 to 49 percent of the terminal groups are OE-capped Catalyst 11 produces a polymer in which about 43 to 46 percent of the terminal groups are OE-crowned.The catalyst 12 produces a polymer in which they are crowned with OE from about 46 to 48 percent of the end groups The catalyst of example 12 is re-evaluated at a catalyst level of 5,000 ppm, a polyol is produced under these conditions with molecular weight of about 2,500, which has about 48 percent coronation with EO, and a polyol of approximate molecular weight 3,200 is produced, which has approximately 38 percent coronation with EO.

EXAMPLE 18 The catalyst example 9 is repeated, except that the ethanol used to decompose the emulsion and wash the catalyst particles is replaced with approximately equal amounts of tri (ethylene glycol) monomethyl ether. The resulting catalyst actively polymerizes OP with a minimum induction period, by means of the ampule discrimination test described in example 17.

EXAMPLE 19 8,995 parts of zinc chloride and 29,725 parts of water are mixed with stirring until the salt dissolves. A solution of H3Co (CN) 6 is prepared in the general manner described in Example 1. A surfactant mixture is prepared by mixing poly (oxyethylene) 5 nonylphenyl ether (Igepal® CO-520 surfactant) and poly (oxyethylene) octylphenyl ether. ) 9 (Igepal® CO-630 surfactant), at a ratio of 2.75: 1 by weight. The DMC catalyst of Example 19 is prepared as follows: 43.274 parts by weight of the H3Co (CN) 6 solution are diluted with 2726 parts of water. 16.004 parts by weight of the surfactant mixture is added to each of the solutions of ZnCl2 and H3Co (CN) 6, with shaking. Then he 37,965 parts by weight of hexane are added to each of the solutions, followed by shaking. Each solution forms a water-in-oil emulsion, with a droplet size of the disperse phase estimated at less than 500 nm. The solutions are then mixed at room temperature and shaken at room temperature for about 17 hours. The proportions of starting materials provide approximately four moles of zinc atoms per mole of cobalt atoms. The mixed solutions retain the form of a water-in-oil emulsion, with a small droplet size. The zinc hexacyanocobaltate catalyst complex precipitates with the droplets dispersed in the aqueous phase. The precipitated catalyst particles are recovered by washing them with ethanol, as described in example 1. The recovered catalyst particles (before drying) are dispersed in a triol of poly (propylene oxide of molecular weight 700 (polyol Voranol® 2070 of Dow Chemical) to form a suspension containing 6 percent dispersed catalyst particles The resulting suspension is dried under vacuum at 50 ° C for four hours, and then overnight at 40 ° C, at atmospheric pressure. The resultant polymerizes actively the propylene oxide in the blister discrimination test of example 17.

EXAMPLE 20 The DMC catalyst of Example 20 is prepared in the following manner: 43.274 parts by weight of the H3Co (CN) 6 solution prepared as described in Example 19 are diluted with 2.726 parts of water. A solution of ZnCl2 is also prepared as in example 19. 32.007 parts by weight of the surfactant mixture of example 19 are added to each of the solutions, with shaking. 9,995 parts of ethylene glycol dimethyl ether are added to each of the solutions. Then 75,931 parts by weight of hexane are added to each of the solutions, followed by shaking. The solutions are then used in the manner described in Example 19 to prepare a DMC catalyst.

EXAMPLE 21 8.995 parts of zinc chloride and 29725 parts of water are mixed with stirring, until the salts are dissolved. A solution of H3Co (CN) 6 is prepared in the general manner described in Example 1. A mixture of surfactants is prepared by mixing nonylphenyl ether of poly (oxyethylene) 5 (Igepal® CO-520 surfactant) and octylphenyl ether of poly. (oxyethylene) 9 (Igepal® CO-630 surfactant) at a weight ratio of 2.75: 1.

The DMC catalyst of Example 21 is prepared in the following manner: 43.274 parts by weight of the H3Co (CN) 6 solution are diluted with 2726 parts of water. 32.007 parts by weight of the surfactant mixture is added to each of the solutions of zinc chloride and H3Co (CN) 6, with shaking. Then 75,931 parts by weight of petroleum ether are added to each of the diluted solutions, followed by shaking. Diluted solutions are then used in the general manner described in Example 1 to prepare a DMC catalyst.

EXAMPLE 22 Example 21 is repeated, except that 9,995 parts of ethylene glycol dimethyl ether are added to each of the diluted solutions.

EXAMPLE 23 Example 22 is repeated, except that the amount of surfactants and petroleum ether is reduced by half.

EXAMPLE 24 A mixture of 40 parts of sooctane and 10 parts of the surfactant Igepal® DM-430 (an ether 3,5- poly (oxyethylene) dialkylphenyl to each of two polypropylene bottles. 1.85 parts of a 40 weight percent solution of ZnCl2 in water and 2.5 parts of glyme is added to the first bottle. Both bottles are shaken separately to disperse the contents of the mixture. The contents of the bottles are then combined and shaken overnight at room temperature. The resulting dispersion is diluted to approximately 500 g with ethanol, and centrifuged for 20 minutes to produce a semi-clear gel (containing the catalyst particles) and a supernatant fluid. The supernatant is decanted and the gel is washed with ethanol and centrifuged twice more. The resulting product is diluted with 70 parts of Voranol® 2070 polyol, and purified by rotary evaporation at 40 ° C overnight. This catalyst has a volume average particle size of about 40 nm. It is evaluated in sequential polymerizations of propylene oxide / ethylene oxide, in the general manner described in Example 17 (at a level of 5,000 ppm) to produce poly (OP) polyols capped with poly (oxyethylene). A polyol with a molecular weight of 2,800 is produced, having 51 percent of primary hydroxyls. Polyols with molecular weights of 2,900 and 3,600 having 45 percent primary hydroxyl are produced. A polyol of molecular weight 3,800 is produced, having 32 percent primary hydroxyl.

Claims (19)

1. - A process for preparing a metal cyanide catalyst, characterized in that it comprises: (A) forming an emulsion having a plurality of water droplets dispersed in an immiscible continuous phase; wherein the water droplets contain a transition metal cyanide compound, and a metal salt which reacts with the transition metal cyanide compound to form a water insoluble metal cyanide catalyst; and (B) subjecting the emulsion to such conditions, that the transition metal cyanide compound and the metal salt react in the water droplets to form the water soluble metal cyanide catalyst.

2. The process according to claim 1, further characterized in that the catalyst has the form of particles having an average particle size, as determined by transmission electron spectroscopy, from about 5 to about 500 nanometers.

3. The process according to claim 1 or 2, further characterized in that step (A) is carried out by: A1) formation of a first emulsion of first drops of water, dispersed in an immiscible continuous phase, where the first drops of water contain a transition metal cyanide compound; A2) formation of a second emulsion of second drops of water dispersed in an immiscible continuous phase; wherein the second water droplets contain a dissolved metal salt which reacts with the transition metal cyanide compound to form a water insoluble metal cyanide catalyst; and A3) mixing the first and second emulsions, under such conditions, that said first drops of water make contact with the second drops of water.

4. The process according to any of claims 1 to 3, further characterized in that the immiscible continuous phase includes a surfactant.

5. The process according to any of claims 1 to 4, further characterized in that the immiscible continuous phase includes a liquid organic compound, which is immiscible with water. 6. The process according to claim 5, further characterized in that the immiscible continuous phase includes a hydrocarbon, an alkanol of 6 or more carbon atoms, or a mixture of at least one hydrocarbon and at least one alkanol of

6. or more carbon atoms.

7. The process according to any of claims 1 to 6, further characterized in that the catalyst is treated with a ligand.

8. The process according to claim 7, further characterized in that the ligand is present during step b).

9. The process according to any of claims 1 to 8, further characterized in that the metal cyanide compound is a hexacyanocobaltate compound and the metal salt is a zinc salt.

10. A process, characterized in that a metal cyanide catalyst is mixed with an alkylene oxide, and the resulting mixture is subjected to conditions including an elevated temperature, sufficient to polymerize the alkylene oxide to form a poly (alkylene oxide) ), wherein the metal cyanide catalyst is the product of a process according to any of claims 1 to 9.

11. The process according to claim 10, further characterized in that the metal cyanide catalyst has an average size of particle, when determined by transmission electron spectroscopy, from about 5 to about 500 nm, before being exposed to an alkylene oxide.

12. The process according to claim 10 or 11, further characterized in that the metal cyanide catalyst has an average particle size, when determined by transmission electron spectroscopy, from about 5 to about 150 nm, before being exposed to an alkylene oxide.

13. - The process according to any of claims 10 to 12, further characterized in that the catalyst is a zinc hexacyanocobaltate catalyst.

14. The process according to any of claims 10 to 13, further characterized in that the catalyst contains an organic ligand.

15. The process according to any of claims 10 to 14, further characterized in that it is carried out in the presence of an initiator compound.

16. The process according to claim 15, further characterized in that the initiator compound is a poly (propylene oxide) and the alkylene oxide is ethylene oxide.

17. The process according to any of claims 10 to 15, further characterized in that the propylene oxide and the ethylene oxide are sequentially polymerized to form a poly (propylene oxide) polyol topped with ethylene oxide. 17.- A process in which a poly (propylene oxide) polymer comprising O2 (propylene oxide) polymer is contacted with EO under polymerization conditions and in the presence of a polymer. catalytically effective amount of a metal cyanide catalyst in the form of particles having an average particle size, when determined by transmission electron spectroscopy, from about 5 to about 500 nm, before expose it to an alkylene oxide.

18. A metal cyanide catalyst in the form of particles having an average particle size, when determined by transmission electron spectroscopy, of about 5 to about 500 nm, before being brought into contact with an alkylene oxide. .

19. A process characterized in that a metal cyanide catalyst of claim 18 is mixed with an alkylene oxide, and the resulting mixture is subjected to conditions including a sufficient high temperature to polymerize the alkylene oxide to form a poly ( alkylene oxide).