A double metal cyanide catalyst, its preparation method and use

Abstract

The present application provides a double metal cyanide catalyst containing a compound represented by general formula (1); general formula (1) is M 1a [M 2b (CN) c ] d ·tM1(X) e ·xL1·yL2·zH2O; wherein L1 is an ether organic ligand and / or an alcohol organic ligand; L2 is an acid anhydride organic ligand. The present application also provides a method for preparing a double metal cyanide catalyst and the use of the double metal cyanide catalyst as described above in the preparation of polyether products. Through the above technical solution, the double metal cyanide catalyst of the present application has low crystallinity, large specific surface area and high catalytic activity; the catalyst of the present application is applied to the synthesis of polyether polyols, and the obtained product has narrow molecular weight distribution and low unsaturation degree, while the reaction has high yield, mild conditions and low catalyst consumption; and the catalyst of the present application does not need to use strong acid or Lewis acid as a promoter to maintain its activity.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis, and more specifically, to a bimetallic cyanide catalyst, its preparation method, and its application. Background Technology

[0002] Polyether polyols are a very important class of nonionic surfactants and the main raw materials for synthesizing polyurethane products. Their products are widely used in various polymer materials such as foam plastics, coatings, elastomers, synthetic leather, and adhesives.

[0003] Coordination ring-opening polymerization catalyzed by bimetallic cyanide catalysts (DMC) is one of the methods for preparing polyether products.

[0004] CN112250856A discloses a bimetallic cyanide complex catalyst, its preparation method, and a method for preparing polypropylene glycol. The catalyst is obtained by in-situ growth of a bimetallic cyanide catalyst modified with transition metal salts, organic ligands, and a co-complexing agent on a mesoporous molecular sieve using a simultaneous dropping method, followed by multiple slurry washings and drying.

[0005] However, existing bimetallic cyanide catalysts have low activity, which not only greatly increases the induction time, but also leaves a large amount of epoxide compounds even after the reaction time is extended. Summary of the Invention

[0006] The purpose of this invention is to improve the activity of bimetallic cyanide catalysts.

[0007] To achieve the above objectives, the present invention provides a bimetallic cyanide catalyst containing a compound of general formula (1); general formula (1) is M 1a [M 2b (CN) c ] d ·tM1(X) e ·xL1·yL2·zH2O; In general formula (1), M1 is Ni 2+ Co 2+ Zn 2+ and Fe 2+ At least one of them, M2 is Fe 3+ Co 3+ Ni 2+ and Cr 3+ At least one of them; X is Cl - ,Br - SO4 2- Or NO3 -a, b, c, d, and e are positive numbers that make the sum of the valences of the elements in general formula (1) zero; L1 is an ether organic ligand and / or an alcohol organic ligand; L2 is an acid anhydride organic ligand; t is any value between 0.7 and 2, x is any value between 0.1 and 2, y is any value between 0.1 and 2, and z is any value between 0.1 and 2.

[0008] This invention also provides a method for preparing a bimetallic cyanide catalyst, the method comprising: under a first stirring condition, firstly adding solution C dropwise to solution A, then adding solution B dropwise, and then performing a second stirring to obtain a slurry; wherein solution A is an aqueous solution containing a metal cyanide complex salt, and the central metal ion in the metal cyanide complex salt is Fe. 3 + Co 3+ Ni 2+ and Cr 3+ At least one of the following; solution B is an aqueous solution containing a metal salt and a first organic ligand, wherein the metal ion in the metal salt is Ni. 2+ Co 2+ Zn 2+ and Fe 2+ At least one of them, the anion being Cl - ,Br - SO4 2- Or NO3 - The solution C is an aqueous solution containing a first organic ligand and a second organic ligand; the first organic ligand is an ether organic ligand and / or an alcohol organic ligand; the second organic ligand is an acid anhydride organic ligand; wherein, the molar ratio of the central metal ion in the metal cyanide complex salt, the metal ion in the metal salt, the first organic ligand, and the second organic ligand is 1:x1:x2:x3; x1 is any value between 2 and 15, x2 is any value between 5 and 80, and x3 is any value between 5 and 50.

[0009] The present invention also provides a bimetallic cyanide catalyst prepared by the method described above.

[0010] The present invention also provides the use of the bimetallic cyanide catalyst described above in the preparation of polyether products.

[0011] The present invention also provides a method for preparing a polyether product, the method comprising: contacting an initiator, a polymerizing monomer and a polymerization catalyst under polymerization conditions to carry out a polymerization reaction; wherein the polymerization catalyst is a bimetallic cyanide catalyst as described above; wherein the polymerization conditions include: a reaction temperature of 100-140℃, preferably 120-140℃; and a reaction pressure of 0.1-0.6MPa, preferably 0.2-0.4MPa.

[0012] Through the above technical solutions, the present invention uses ethers or alcohols and acid anhydrides as dual organic ligands to prepare bimetallic cyanides. The catalyst has low crystallinity, large specific surface area, and high catalytic activity. When applied to the synthesis of polyether polyols, the resulting products have a narrow molecular weight distribution and low unsaturation. At the same time, the reaction yield is high, the conditions are mild, and the catalyst dosage is low. Furthermore, the catalyst of the present invention does not require the use of strong acids or Lewis acids as promoters to maintain its activity.

[0013] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0014] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0015] Figure 1 This is a SEM image of the DMC-1 catalyst prepared in Example 1 at a magnification of 15000.

[0016] Figure 2 The image shown is a SEM image of the DMC-1 catalyst prepared in Example 1 at a magnification of 30,000.

[0017] Figure 3 The image shows the XRD pattern of the DMC-1 catalyst prepared in Example 1. Detailed Implementation

[0018] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0019] This invention provides a bimetallic cyanide catalyst containing a compound of general formula (1); general formula (1) is M 1a [M 2b (CN) c ] d ·tM1(X) e ·xL1·yL2·zH2O; In general formula (1), M1 is Ni 2+ Co 2 + Zn 2+ and Fe 2+ At least one of them, M2 is Fe 3+ Co 3+ Ni 2+ and Cr 3+ At least one of them; X is Cl - ,Br- SO4 2- Or NO3 - a, b, c, d, and e are positive numbers that make the sum of the valences of the elements in general formula (1) zero; L1 is an ether organic ligand and / or an alcohol organic ligand; L2 is an acid anhydride organic ligand; t is any value between 0.7 and 2, x is any value between 0.1 and 2, y is any value between 0.1 and 2, and z is any value between 0.1 and 2.

[0020] Preferably, M1 is Zn 2+ M2 is Co 3+ and / or Fe 3+ .

[0021] Optionally, the ether organic ligand is at least one selected from butyl ether, ethylene glycol dimethyl ether, ethyl propyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, methyl tert-butyl ether, and diethylene glycol monomethyl ether; the alcohol organic ligand is at least one selected from n-butanol, isobutanol, tert-butanol, n-propanol, ethylene glycol, propylene glycol, glycerol, isopropanol, pentaerythritol, and polyether polyol; and the polyether polyol has a molecular weight of 200-1000.

[0022] Optionally, the anhydride organic ligand is at least one selected from succinic anhydride, maleic anhydride, glutaric anhydride, phthalic anhydride, itaconic anhydride, norbornene anhydride, 2-benzylsuccinic anhydride, 2-methylsuccinic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, cyclobutane-1,2-dicarboxylic anhydride, and cyclopentane-1,2-dicarboxylic anhydride.

[0023] Preferably, t is any value between 0.8 and 1.4, x is any value between 1 and 2, y is any value between 0.2 and 0.9, and z is any value between 0.1 and 1.

[0024] Optionally, the compound represented by general formula (1) is the compound represented by formula (2), formula (3) or formula (4); formula (2) is Zn3[Co(CN)6]2·0.88ZnCl2·1.79L1·0.49L2·0.44H2O; formula (3) is Zn3[Co(CN)6]2·0.92ZnBr2·1.65L1·0.54L2·0.50H2O; formula (4) is Zn3[Fe(CN)6]2·Zn(NO3)2·1.86L1·0.36L2·0.46H2O; in formula (2), L1 is tert-butanol and L2 is maleic anhydride; in formula (3), L1 is propylene glycol and L2 is maleic anhydride; in formula (4), L1 is ethylene glycol dimethyl ether and L2 is tetrahydrophthalic anhydride.

[0025] This invention also provides a method for preparing a bimetallic cyanide catalyst, the method comprising: under a first stirring condition, firstly adding solution C dropwise to solution A, then adding solution B dropwise, and then performing a second stirring to obtain a slurry; wherein solution A is an aqueous solution containing a metal cyanide complex salt, and the central metal ion in the metal cyanide complex salt is Fe. 3 + Co 3+ Ni 2+ and Cr 3+ At least one of the following; solution B is an aqueous solution containing a metal salt and a first organic ligand, wherein the metal ion in the metal salt is Ni. 2+ Co 2+ Zn 2+ and Fe 2+ At least one of them, the anion being Cl - ,Br - SO4 2- Or NO3 - The solution C is an aqueous solution containing a first organic ligand and a second organic ligand; the first organic ligand is an ether organic ligand and / or an alcohol organic ligand; the second organic ligand is an acid anhydride organic ligand; wherein, the molar ratio of the central metal ion in the metal cyanide complex salt, the metal ion in the metal salt, the first organic ligand, and the second organic ligand is 1:x1:x2:x3; x1 is any value between 2 and 15, x2 is any value between 5 and 80, and x3 is any value between 5 and 50.

[0026] Optionally, the method further includes: performing solid-liquid separation on the slurry to obtain solid material, and then washing and drying the solid material.

[0027] Preferably, the washing solution used for washing is an aqueous solution containing 10-50 mol / L of the first organic ligand. In this preferred case, it is beneficial to maintain or increase the content of the first organic ligand in the catalyst.

[0028] Optionally, the drying temperature is 80-120℃ and the time is 12-24 hours.

[0029] Preferably, the metal ion in the metal salt is Zn. 2+ The metal ion in the metal cyanide complex salt is Co. 3+ and / or Fe 3+ .

[0030] Optionally, the ether organic ligand is at least one selected from butyl ether, ethylene glycol dimethyl ether, ethyl propyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, methyl tert-butyl ether, and diethylene glycol monomethyl ether; the alcohol organic ligand is at least one selected from n-butanol, isobutanol, tert-butanol, n-propanol, ethylene glycol, propylene glycol, glycerol, isopropanol, pentaerythritol, and polyether polyol; and the polyether polyol has a molecular weight of 200-1000.

[0031] Optionally, the anhydride organic ligand is at least one selected from succinic anhydride, maleic anhydride, glutaric anhydride, phthalic anhydride, itaconic anhydride, norbornene anhydride, 2-benzylsuccinic anhydride, 2-methylsuccinic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, cyclobutane-1,2-dicarboxylic anhydride, and cyclopentane-1,2-dicarboxylic anhydride.

[0032] Preferably, the molar ratio of the central metal ion in the metal cyanide complex salt, the metal ion in the metal salt, the first organic ligand, and the second organic ligand is 1:x1:x2:x3, where x1 is any value between 4 and 10, x2 is any value between 10 and 50, and x3 is any value between 10 and 25.

[0033] Optionally, in solution A, the molar concentration of the metal cyanide complex salt is 0.1-1 mol / L; in solution B, the molar concentration of the metal salt is 1-4 mol / L, and the molar concentration of the first organic ligand is 5-20 mol / L; in solution C, the molar concentration of the first organic ligand is 1-4 mol / L, and the molar concentration of the second organic ligand is 2-10 mol / L.

[0034] Preferably, the metal cyanide complex salt in solution A is at least one of potassium ferrocyanide and potassium cobalt cyanide; and the metal salt in solution B is at least one of zinc bromide, zinc chloride, zinc nitrate, and zinc sulfate.

[0035] Preferably, the first organic ligand is at least one of tert-butanol, propylene glycol, and ethylene glycol dimethyl ether; and the second organic ligand is maleic anhydride and / or tetrahydrophthalic anhydride.

[0036] Optionally, the conditions for the first stirring and the second stirring each independently include: a rotation speed of 500-1000 rpm, a time of 0.5-4 hours, and a temperature of 30-70℃.

[0037] The present invention also provides a bimetallic cyanide catalyst prepared by the method described above.

[0038] The present invention also provides the use of the bimetallic cyanide catalyst described above in the preparation of polyether products.

[0039] The present invention also provides a method for preparing a polyether product, the method comprising: contacting an initiator, a polymerizing monomer and a polymerization catalyst under polymerization conditions to carry out a polymerization reaction; wherein the polymerization catalyst is a bimetallic cyanide catalyst as described above; wherein the polymerization conditions include: a reaction temperature of 100-140℃, preferably 120-140℃; and a reaction pressure of 0.1-0.6MPa, preferably 0.2-0.4MPa.

[0040] Optionally, the initiator may be at least one of the following initiators: polypropylene glycol initiator, propylene glycol, ethylene glycol, diol, glycerol trimethylolpropane, tris(2-hydroxyethyl) isocyanate, pentaerythritol, xylitol, sorbitol, sucrose, diethylamine, diethylenetriamine, etc.; and the polymerizing monomer may be propylene oxide, butylene oxide, and / or ethylene oxide.

[0041] The present invention will be further described in detail below through embodiments. Unless otherwise specified, the raw materials used in the embodiments are all commercially available.

[0042] In the following examples and comparative examples, the hydroxyl value of the polyether products was determined according to the phthalic anhydride method in GB / T7383-2007 and recorded as mg[KOH] / g. The Dalton number-average molecular weight (Mn) and weight-average molecular weight (Mw) of the polyether products were determined using a Waters 1515 gel permeation chromatography (GPC) system, using tetrahydrofuran as the mobile phase, a column temperature of 35°C, a sample concentration of 1.5-2.5 mg / mL, and calibrated using polystyrene as a standard. The bromine value of the polyether products was determined according to SH / T0630-1996 and recorded as g / (100 mL). The molecular weight dispersion (MWD) of the polyether products was calculated as the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) as measured above. The formula for calculating the degree of unsaturation of the polyether products is as follows: That is The unit is mmol / L. The catalyst induction time is recorded during the reaction: timing begins after the reactor temperature reaches the set reaction temperature, and the induction time is defined as the point at which a "temperature rise and pressure drop" or a significant pressure decrease occurs.

[0043] Example 1

[0044] This embodiment prepares a bimetallic cyanide complex catalyst with organic ligand L1 being tert-butanol and organic ligand L2 being maleic anhydride. The specific preparation steps are as follows:

[0045] (1) Prepare the following solutions: Solution A (0.4 mol / L potassium cobalt cyanide aqueous solution), Solution B (aqueous solution containing 2.4 mol / L zinc chloride and 6.3 mol / L tert-butanol), Solution C (aqueous solution containing 4 mol / L maleic anhydride and 1.7 mol / L tert-butanol).

[0046] (2) Under oil bath conditions at 50℃, solution C was slowly added dropwise to solution A, which was stirred at 500 r / min, for 30 min. After stirring for 2 h, solution B was added dropwise to the solution for 30 min. After the addition was complete, stirring and mixing continued for 3 h. The molar ratio of potassium cobalt cyanide, zinc chloride, tert-butanol and maleic anhydride was 1:6:26:12.

[0047] (3) After stirring, the resulting slurry was cooled and filtered to obtain a filter cake. The filter cake was washed three times with an aqueous solution containing 20 mol / L tert-butanol to obtain the final catalyst filter cake. The final filter cake was vacuum dried at 80°C to constant weight, ground, and the catalyst was obtained and named DMC-1.

[0048] Catalyst composition determination: The content of each component in catalyst DMC-1 was determined by combining inductively coupled plasma atomic emission spectrometry (ICP) and elemental analysis (EA), and the approximate composition of DMC-1 was calculated. Catalyst DMC-1 is Zn3[Co(CN)6]2·0.88ZnCl2·1.79L1·0.49L2·0.44H2O, where L1 is tert-butanol and L2 is maleic anhydride.

[0049] BET analysis revealed that the specific surface area of ​​DMC-1 was 742.12 m². 2 / g, pore volume is 0.31 cm³ 3 / g, with an average pore size of 2.86 nm.

[0050] Example 2

[0051] The catalyst was prepared according to the method of Example 1, except that: the metal cyanide complex salt was potassium cobalt cyanide, the metal salt was zinc bromide, the first organic ligand L1 was propylene glycol, and the second organic ligand L2 was maleic anhydride. The catalyst of this embodiment was named DMC-2, with an approximate composition of Zn3[Co(CN)6]2·0.92ZnBr2·1.65L1·0.54L2·0.50H2O, wherein L1 is propylene glycol and L2 is maleic anhydride.

[0052] Example 3

[0053] The catalyst was prepared according to the method of Example 1, except that: the metal cyanide complex salt was potassium ferricyanide, the metal salt was zinc nitrate, the organic ligand L1 was ethylene glycol dimethyl ether, and the organic ligand L2 was tetrahydrophthalic anhydride. The catalyst of this example is named DMC-3, with an approximate composition of Zn3[Fe(CN)6]2·Zn(NO3)2·1.86L1·0.36L2·0.46H2O, wherein L1 is ethylene glycol dimethyl ether and L2 is tetrahydrophthalic anhydride.

[0054] Example 4

[0055] This embodiment tests the synthesis of polypropylene glycol from PPG-2000. The specific steps are as follows:

[0056] 3.6 g of polypropylene glycol initiator with Mn of 400 and 32 mg of catalyst DMC-1 prepared in Example 1 were added to a high-pressure reactor. After multiple purgings with nitrogen, the temperature was raised to 130°C, and 2.6 g of propylene oxide was added to the reactor. The rotation speed was controlled at 500 r / min, and the initial pressure was 0.25 MPa. After the reaction pressure dropped to 0.12 MPa, a mixture of 8.4 g of polypropylene glycol with Mn of 400 and 23.5 g of propylene oxide was continued to be fed. After the feeding was completed, 26.1 g of propylene oxide was continued to be fed. After reacting for 2 hours, unreacted epoxy monomers were removed, and the product and catalyst were separated by filtration to obtain the polypropylene glycol product. The effect of different reaction temperatures on the performance of the polypropylene glycol product is shown in Table 1. The reaction temperature is 100°C-140°C, preferably 120°C-140°C. The reaction pressure is 0.1 MPa - 0.6 MPa, preferably 0.2 MPa - 0.4 MPa.

[0057] Table 1

[0058]

[0059] Example 5

[0060] This example tests the synthesis of polypropylene glycol from PPG-1000:

[0061] 3.6 g of polypropylene glycol initiator with Mn of 400 and 9 mg of catalyst DMC-2 prepared in Example 2 were added to a high-pressure reactor. After multiple purgings with nitrogen, the temperature was raised to 120 °C, and 0.9 g of propylene oxide was added to the reactor. The rotation speed was controlled at 700 r / min, and the initial pressure was 0.20 MPa. After the reaction pressure dropped to 0.10 MPa, a mixture of 8.4 g of polypropylene glycol with Mn of 400 and 8.0 g of propylene oxide was continued to be fed. After the feeding was completed, 8.7 g of propylene oxide was continued to be fed. After reacting for 2 h, unreacted epoxy monomers were removed, and the product and catalyst were separated by filtration to obtain polypropylene glycol product with a yield of 93.1%. The polyether product had a molecular weight dispersion of 1.08, a hydroxyl value of 95.3 mg[KOH] / g, a bromine value of 0.15 g / (100 mL), and an unsaturation degree of 9.39 mmol / L.

[0062] Example 6

[0063] This example tests the synthesis of polypropylene glycol from PPG-3000:

[0064] This embodiment uses polypropylene glycol with a Mn of 200 as an initiator to synthesize high molecular weight polyether polyols. The specific steps are as follows: 1.5g of polypropylene glycol initiator and 23mg of catalyst DMC-3 prepared in Example 3 were added to a high-pressure reactor. After multiple purgings with nitrogen, the temperature was raised to 140℃, and 4.2g of epoxide was added to the reactor. The rotation speed was controlled at 600r / min, and the initial pressure was 0.35MPa. After the reaction pressure dropped to 0.17MPa, a mixture of 1.5g of polypropylene glycol with a Mn of 200 and 16.8g of epoxide was continued to be fed. After the feeding was completed, 21.0g of epoxide was continued to be fed. After reacting for 3 hours, unreacted monomers were removed, and the product and catalyst were separated by filtration to obtain polypropylene glycol product with a yield of 90.5%. The polyether product has a molecular weight dispersion of 1.08, a hydroxyl value of 39.1 mg[KOH] / g, a bromine value of 0.14 g / (100mL), and an unsaturation of 8.76 mmol / L.

[0065] Comparative Example 1

[0066] Preparation of zinc cobalt cyanide Zn3[Co(CN)6]2·12H2O:

[0067] The preparation steps of Zn3[Co(CN)6]2·12H2O are the same as in Example 1, except that no organic ligands are added, and the catalyst is named DMC-4.

[0068] Comparative Example 2

[0069] The catalyst preparation steps are the same as in Example 1, except that the organic ligand L2 is not added, and the catalyst is named DMC-5.

[0070] Comparative Example 3

[0071] The catalyst preparation steps are the same as in Example 1, except that the organic ligand L1 is not added, and the catalyst is named DMC-6.

[0072] Comparative Example 4

[0073] This comparative test tested the synthesis of PPG-2000 polypropylene glycol. The preparation steps were the same as in Example 4, except that the catalyst used was DMC-4. The yield of the prepared polypropylene glycol product was less than 5%.

[0074] Comparative Example 5

[0075] This comparative example tested the synthesis of PPG-2000 polypropylene glycol. The preparation steps were the same as in Example 4, except that DMC-5 catalyst was used. The yield of the prepared polypropylene glycol product was 46.2%.

[0076] Comparative Example 6

[0077] This comparative example tested the synthesis of PPG-2000 polypropylene glycol. The preparation steps were the same as in Example 4, except that DMC-6 catalyst was used. The yield of the prepared polypropylene glycol product was 57.8%.

[0078] From Examples 1-6 and Comparative Examples 1-6 and Figure 1-3 It can be seen that the DMC-1 catalyst prepared in Example 1 has a plate-like structure with a crystal thickness of 0.5-2 μm and a diameter of 9-40 μm. The XRD pattern of the DMC-1 catalyst shows that the prepared DMC-1 catalyst is in a state where amorphous and monoclinic crystals coexist, mainly in the amorphous form, and with extremely low crystallinity. This may be because the addition of organic ligands L1 and L2 reacts with Zn. 2+ Coordination occurs, especially with the organic ligand L2, which is an anhydride with numerous oxygen-containing groups, and interacts with Zn. 2+The strong coordination interaction effectively suppresses the formation of catalyst crystals, resulting in the prepared DMC crystals primarily existing in an amorphous state. The DMC catalyst of this invention exhibits low crystallinity, and the low-crystallinity catalyst prepared by this invention demonstrates high catalytic activity during the synthesis of polyethers. The DMC catalyst prepared in Examples 1-3, based on data characterization analysis, can be inferred to be a bimetallic cyanide catalyst with dual organic ligand complexes. Data from Examples 4, 5, and 6 show that the DMC catalyst of this invention has good catalytic activity for the preparation of polyether polyols, does not require the addition of acid promoters to maintain the catalytic activity of the DMC catalyst, has a short induction period, and can prepare the target product in a relatively short time with a high yield. At the same time, the product quality is good, with low unsaturation and a narrow molecular weight distribution. The experimental results of Examples 4 and Comparative Examples 4, 5, and 6 show that without the addition of organic ligands L1 and L2, only the Zn3[Co(CN)6]2·12H2O catalyst can be obtained, which has almost no catalytic activity for the reaction system. When only organic ligands L1 or L2 are added, the activity of the prepared DMC catalyst is low, not only does the induction time increase significantly (greater than 30 min), but even with extended reaction time, a large amount of epoxide remains.

[0079] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0080] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0081] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A bimetallic cyanide catalyst, characterized in that, This bimetallic cyanide catalyst contains a compound represented by general formula (1); General formula (1) is M 1a [M 2b (CN) c ] d ·tM1(X) e ·xL1·yL2·zH2O; In general formula (1), M1 is Zn 2+ M2 is Fe 3+ and / or Co 3+ X is Cl - ,Br - SO4 2- Or NO3 - a, b, c, d, and e are positive numbers that make the sum of the valences of the elements in general formula (1) zero; L1 is an ether organic ligand and / or an alcohol organic ligand; L2 is an acid anhydride organic ligand; t is any value between 0.7 and 2, x is any value between 0.1 and 2, y is any value between 0.1 and 2, and z is any value between 0.1 and 2. The ether organic ligand is at least one selected from butyl ether, ethylene glycol dimethyl ether, ethyl propyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, methyl tert-butyl ether, and diethylene glycol monomethyl ether; the alcohol organic ligand is at least one selected from n-butanol, isobutanol, tert-butanol, n-propanol, ethylene glycol, propylene glycol, glycerol, isopropanol, pentaerythritol, and polyether polyol; the polyether polyol has a molecular weight of 200-1000; the anhydride organic ligand is at least one selected from succinic anhydride, maleic anhydride, glutaric anhydride, phthalic anhydride, itaconic anhydride, norbornene anhydride, 2-benzylsuccinic anhydride, 2-methylsuccinic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, cyclobutane-1,2-dicarboxylic anhydride, and cyclopentane-1,2-dicarboxylic anhydride.

2. The bimetallic cyanide catalyst according to claim 1, wherein, t is any value between 0.8 and 1.4, x is any value between 1 and 2, y is any value between 0.2 and 0.9, and z is any value between 0.1 and 1.

3. The bimetallic cyanide catalyst according to claim 1 or 2, wherein, The compound represented by general formula (1) is the compound represented by formula (2), formula (3) or formula (4); Equation (2) is Zn3[Co(CN)6]2·0.88ZnCl2·1.79L1·0.49L2·0.44H2O; Equation (3) is Zn3[Co(CN)6]2·0.92ZnBr2·1.65L1·0.54L2·0.50H2O; Equation (4) is Zn3[Fe(CN)6]2·Zn(NO3)2·1.86L1·0.36L2·0.46H2O; In formula (2), L1 is tert-butanol and L2 is maleic anhydride; in formula (3), L1 is propylene glycol and L2 is maleic anhydride; in formula (4), L1 is ethylene glycol dimethyl ether and L2 is tetrahydrophthalic anhydride.

4. A method for preparing a bimetallic cyanide catalyst, characterized in that, The method includes: Under the first stirring condition, solution C is first added dropwise to solution A, then solution B is added dropwise, and then the second stirring is carried out to obtain a slurry; Solution A is an aqueous solution containing a metal cyanide complex salt, wherein the central metal ion in the metal cyanide complex salt is Fe. 3+ and / or Co 3+ ; Solution B is an aqueous solution containing a metal salt and a first organic ligand, wherein the metal ion in the metal salt is Zn. 2+ The anion is Cl. - ,Br - SO4 2- Or NO3 - ; The solution C is an aqueous solution containing a first organic ligand and a second organic ligand; The first organic ligand is an ether organic ligand and / or an alcohol organic ligand; the second organic ligand is an acid anhydride organic ligand; Wherein, the molar ratio of the central metal ion in the metal cyanide complex salt, the metal ion in the metal salt, the first organic ligand, and the second organic ligand is 1:x1:x2:x3; x1 is any value between 2 and 15, x2 is any value between 5 and 80, and x3 is any value between 5 and 50. The ether organic ligand is at least one selected from butyl ether, ethylene glycol dimethyl ether, ethyl propyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, methyl tert-butyl ether, and diethylene glycol monomethyl ether; the alcohol organic ligand is at least one selected from n-butanol, isobutanol, tert-butanol, n-propanol, ethylene glycol, propylene glycol, glycerol, isopropanol, pentaerythritol, and polyether polyol; the polyether polyol has a molecular weight of 200-1000; The anhydride organic ligands are at least one of succinic anhydride, maleic anhydride, glutaric anhydride, phthalic anhydride, itaconic anhydride, norbornene anhydride, 2-benzylsuccinic anhydride, 2-methylsuccinic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, cyclobutane-1,2-dicarboxylic anhydride, and cyclopentane-1,2-dicarboxylic anhydride.

5. The method according to claim 4, wherein, The method further includes: performing solid-liquid separation on the slurry to obtain solid material, and then washing and drying the solid material; The washing solution used is an aqueous solution containing 10-50 mol / L of the first organic ligand; The drying temperature is 80-120℃, and the time is 12-24 hours.

6. The method according to claim 4 or 5, wherein, The molar ratio of the central metal ion in the metal cyanide complex salt, the metal ion in the metal salt, the first organic ligand, and the second organic ligand is 1:x1:x2:x3, where x1 is any value between 4 and 10, x2 is any value between 10 and 50, and x3 is any value between 10 and 25.

7. The method according to claim 4 or 5, wherein, In solution A, the molar concentration of the metal cyanide complex salt is 0.1-1 mol / L; in solution B, the molar concentration of the metal salt is 1-4 mol / L, and the molar concentration of the first organic ligand is 5-20 mol / L; in solution C, the molar concentration of the first organic ligand is 1-4 mol / L, and the molar concentration of the second organic ligand is 2-10 mol / L.

8. The method according to claim 4 or 5, wherein, The metal cyanide complex salt in solution A is potassium ferricyanide and / or potassium cobalt cyanide; the metal salt in solution B is at least one of zinc bromide, zinc chloride, zinc nitrate, and zinc sulfate; the first organic ligand is at least one of tert-butanol, propylene glycol, and ethylene glycol dimethyl ether; the second organic ligand is maleic anhydride and / or tetrahydrophthalic anhydride. The conditions for the first stirring and the second stirring each independently include: a rotation speed of 500-1000 rpm, a time of 0.5-4 hours, and a temperature of 30-70℃.

9. The bimetallic cyanide catalyst prepared by the method according to any one of claims 4-8.

10. Use of the bimetallic cyanide catalyst according to any one of claims 1-3 and 9 in the preparation of polyether products.

11. A method for preparing a polyether product, characterized in that, The method includes: contacting an initiator, a polymerizable monomer, and a polymerization catalyst under polymerization conditions to carry out a polymerization reaction; the polymerization catalyst is a bimetallic cyanide catalyst as described in any one of claims 1-3 and 9; the polymerization conditions include: a reaction temperature of 100-140℃ and a reaction pressure of 0.1-0.6 MPa.

12. The method according to claim 11, wherein, The polymerization conditions include: a reaction temperature of 120-140℃ and a reaction pressure of 0.2-0.4MPa.

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