Process for the preparation of a bimetallic liquid phase catalyst, catalyst and process for the preparation of polyether polyols using the same

Abstract

The application discloses a preparation method of a bimetallic liquid-phase catalyst, the catalyst and a method for preparing polyether polyol by using the same. A cobalt-zinc bimetallic complex catalyst is prepared by using cobalt raw materials, zinc raw materials, a washing liquid recovery liquid, metal hydroxides and a ligand in specific proportions, and the bimetallic liquid-phase catalyst is obtained by further mixing the cobalt-zinc bimetallic complex catalyst with a multifunctional intermediate uniformly. In the method, the addition of the washing liquid recovery liquid makes the yield of the catalyst higher, and the action of the two kinds of hydroxides together with the washing liquid recovery liquid makes the particle size of the catalyst smaller, and the activity and the catalytic efficiency of the catalyst higher. The catalyst prepared by using the method can be used for polyether production, and can be used for preparing polyether with narrow distribution, low unsaturation and high molecular weight, and the catalyst consumption is small, and the yield of the obtained polyether product is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of industrial catalysis technology, in particular to a preparation method of a bimetallic liquid phase catalyst, the catalyst and a method for preparing polyether polyol using the same. BACKGROUND

[0002] Polyether polyol is an important raw material for the polyurethane industry. There are three types of catalysts for producing polyether, namely anionic catalyst, cationic catalyst and metal complex catalyst. Among them, the bimetal cyanide complex catalyst (i.e. DMC bimetal catalyst) is a research hotspot in recent years due to its excellent performance. The polyether polyol prepared by using the DMC bimetal catalyst overcomes the shortcomings of the traditional base catalyst, such as wide molecular weight distribution and low functionality. At present, the production technology of the new type of polyether catalyst has been mature abroad, and products have been put on the market. In recent years, domestic research in this regard has also begun. However, the DMC catalyst is a solid powder, which needs to be manually added during production, and there is dust pollution, which is not as convenient as liquid catalyst.

[0003] Although patent CN107118341 A synthesizes a liquid catalyst, it does not wash away the metal ions in the catalyst. As we all know, metal ions such as potassium ions have a great toxic effect on catalysts, so this kind of catalyst cannot play a good catalytic role.

[0004] If you want to reduce the content of potassium ions, you usually use multiple washing methods, but this will inevitably produce a large amount of waste liquid, which will bring new problems.

[0005] Therefore, there is still a need for a new preparation method of bimetallic liquid catalyst, which can overcome the above problems and ensure high catalytic activity. SUMMARY

[0006] The purpose of the present application is to provide a preparation method of a high-activity bimetallic liquid catalyst, which recovers and utilizes the washing liquid, utilizes the synergistic effect of metal hydroxide 1, metal hydroxide 2 and washing liquid recovery liquid, changes the crystalline morphology of the catalyst, and obtains a catalyst with a narrower particle size distribution (100±20 μm), thereby significantly improving the activity of the catalyst.

[0007] Another purpose of the present application is to provide a bimetallic liquid catalyst prepared by the above method.

[0008] Still another purpose of the present application is to provide a method for preparing polyether polyol using the bimetallic liquid catalyst.

[0009] In order to achieve the above-mentioned purposes of the present application, the following technical solutions are adopted:

[0010] A preparation method of a bimetallic liquid phase catalyst, comprising the following steps:

[0011] 1) mixing zinc raw material, metal hydroxide 1, metal hydroxide 2 and part of the washing liquid recovery liquid in a certain proportion to obtain a mixture, mixing cobalt raw material with another part of the washing liquid recovery liquid to obtain a catalyst precursor;

[0012] 2) mixing the washing liquid recovery liquid with ligand X and ligand Y in a certain proportion to obtain a catalyst crude product;

[0013] 3) centrifuging the catalyst crude product obtained in step 2) to obtain a solid, mixing ligand X with water in a 1:3 ratio to obtain a washing liquid, mixing the washing liquid with the obtained solid to dissolve potassium ions in the solid, then centrifuging to obtain a solid, recovering the washing liquid, adding new washing liquid to continue dissolving potassium ions in the solid, and repeating the above operations until the potassium ion test in the washing liquid recovery liquid after centrifugation is qualified;

[0014] 4) mixing the potassium ion qualified catalyst obtained in step 3) with a multifunctional intermediate in a certain proportion to obtain the bimetallic liquid phase catalyst.

[0015] In a specific embodiment, the zinc raw material in step 1) is selected from one or more of zinc-containing salts, preferably selected from one or more of inorganic zinc salts or organic zinc salts, more preferably zinc chloride; the addition amount of the zinc raw material is 20-40 parts, preferably 20-30 parts, more preferably 25 parts;

[0016] Preferably, the metal hydroxide 1 is selected from one or more of iron hydroxide, ferrous hydroxide, zinc hydroxide, copper hydroxide, preferably iron hydroxide; the addition amount of the metal hydroxide 1 is 5-15 parts, preferably 9 parts;

[0017] Preferably, the metal hydroxide 2 is selected from one or more of calcium hydroxide, magnesium hydroxide, aluminum hydroxide, preferably calcium hydroxide; the addition amount of the metal hydroxide 2 is 5-15 parts, preferably 13 parts.

[0018] In a specific embodiment, the washing liquid recovery liquid is the recovered washing liquid after centrifugation of the catalyst in step 3); preferably, the addition amount of the part of the washing liquid recovery liquid required for preparing the mixture in step 1) is 50-100 parts, preferably 70 parts;

[0019] Preferably, the cobalt raw material is selected from one or more of cobalt-containing cyanide or cyan-containing cobalt salt, preferably one or more of cyan-containing cobalt salt, more preferably potassium hexacyanocobaltate; the addition amount of the cobalt raw material is 20-50 parts, preferably 20-30 parts, more preferably 26 parts;

[0020] Preferably, the amount of the other part of the washing solution recovery liquid mixed with the cobalt raw material is 10-80 parts, preferably 50 parts.

[0021] In a specific embodiment, the time for dropping the mixed solution of the cobalt raw material and the other part of the washing solution recovery liquid into the mixed solution in step 1) is 15-100 min, preferably 20-60 min, and more preferably 45 min.

[0022] In a specific embodiment, the ligand X is selected from one or more of organic compounds containing heteroatoms, preferably selected from one or more of alcohols, ethers and ketones, and further preferably t-butyl alcohol;

[0023] Preferably, the ligand Y is selected from one or more of organic solvents, preferably selected from one or more of polyethers, and further preferably polyether 204 and / or polyether 305.

[0024] In a specific embodiment, the amount of the ligand X in step 2) is 50-100 parts, preferably 65-75 parts, and further preferably 70 parts;

[0025] Preferably, the amount of the ligand Y in step 2) is 3-20 parts, preferably 5-10 parts, and further preferably 7 parts;

[0026] Preferably, the amount of the washing solution recovery liquid in step 2) is 25-70 parts, preferably 30-65 parts, and further preferably 60 parts.

[0027] In a specific embodiment, the centrifugal separation in step 3) uses a high-speed centrifuge, and the centrifugal speed is 3000-5000 r / min, preferably 4000 r / min; and the centrifugal time is 5-20 min, preferably 10 min.

[0028] Preferably, the content of potassium ions in the washing solution recovery liquid in step 3) is considered to be qualified for testing if it is 500 ppm or less, preferably 300-5 ppm.

[0029] In a specific embodiment, the multifunctional intermediate in step 4) is selected from one or more of polyethers or polyesters, preferably one or more of polyethers, and further preferably two-function polyethers with a molecular weight of 700.

[0030] In a specific embodiment, the mass ratio of the potassium ion qualified catalyst to the multifunctional intermediate in step 4) is 1:1-1:10, preferably 1:5.

[0031] In another aspect, the bimetallic liquid phase catalyst prepared by the aforementioned preparation method, wherein the particle size of the catalyst particles is 100±20 μm, and the potassium ion content is 500 ppm or less, preferably 300-5 ppm.

[0032] In still another aspect, a method for preparing a polyether polyol, comprising the step of preparing the polyether polyol in the presence of the bimetallic liquid phase catalyst prepared by the aforementioned method, using a polyether having a molecular weight greater than 500 as a starter.

[0033] Compared with the prior art, the present application has the following advantages:

[0034] (1) In the catalyst synthesis process of the present application, the metal hydroxide 1 and the metal hydroxide 2 synergistically act with the wash liquor recovery liquid, the crystal nucleus distribution increases, and thus the catalyst particle size becomes smaller (100±20 μm), the stability is enhanced, the catalyst activity is significantly improved, and the metal hydroxide can be finally washed away with the wash liquor without the generation of side reactions.

[0035] (2) In the catalyst synthesis process of the present application, the product can continue to add the wash liquor recovery liquid as a raw material to the reaction under the condition of reducing the potassium ion, not only without generating waste liquid, but also the residual ions in the reaction can be utilized to continue the reaction, not only improving the yield, but also without any waste liquid generation, and the process is more green and environmentally friendly.

[0036] (3) The bimetallic liquid phase catalyst prepared by the present application is an emulsion catalyst, which is easy to add to the reaction system, avoids dust pollution, and can be better dispersed in the reaction system to fully improve the catalytic efficiency. The emulsion bimetallic liquid phase catalyst prepared by the present application can catalyze the synthesis of high molecular weight polyether polyol products with narrow molecular weight distribution and low unsaturation, and the catalyst residue will not affect the performance of the obtained polyether polyol product and the subsequent prepared polyurethane product. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 The figure is the molecular weight distribution graph of the polyether polyol prepared by Example 1 of the present application.

[0038] Figure 2 The figure is the molecular weight distribution graph of the polyether polyol prepared by Comparative Example 1 of the present application. DETAILED DESCRIPTION

[0039] In order to better understand the technical solutions of the present application, the following examples will further illustrate the method provided by the present application, but the present application is not limited to the listed examples, and any other known changes within the scope of the claims of the present application should also be included.

[0040] The bimetallic liquid phase catalyst of the present application is used for the preparation of polyether polyols, and its preparation process can refer to the prior art, for example, the reaction temperature is 90-180℃, the reaction pressure is -0.1-2Mpa, and the addition amount of the catalyst is 10-2000ppm.

[0041] Zinc chloride, tert-butyl alcohol, potassium hexacyanocobaltate, iron hydroxide, zinc hydroxide, polyether 204, polyether 305 are all purchased from Angene Chemical Co., Ltd.

[0042] Example 1

[0043] 1) Preparation method of bimetallic liquid phase catalyst:

[0044] A) 20g of zinc chloride, 8g of zinc hydroxide, 5g of iron hydroxide and 50g of wash recovery liquid are mixed and stirred uniformly; 20g of potassium hexacyanocobaltate is mixed uniformly with 30g of wash recovery liquid, and is added dropwise into the reaction liquid, and the dropwise adding time is 15 minutes; 60g of wash recovery liquid is stirred uniformly with 65g of tert-butyl alcohol and 5g of polyether 305, and is added into the reaction liquid to obtain a crude catalyst.

[0045] B) The above-mentioned crude catalyst is centrifuged at 4000rpm for 10min to obtain a solid, the tert-butyl alcohol and water are configured into a wash liquid in a ratio of 1:3, the wash liquid is mixed uniformly with the obtained solid to dissolve potassium ions in the solid, and then centrifugation is carried out to obtain a solid, the wash recovery liquid is recovered, new wash liquid is added to continue to dissolve potassium ions in the solid, and the above operation is repeated multiple times until the potassium ion test in the wash recovery liquid after centrifugation is less than 20ppm; then the potassium ion qualified solid obtained by centrifugation is mixed uniformly with polyether with a molecular weight of 700 in a mass ratio of 1:5 to obtain a final new emulsion catalyst.

[0046] 2) Synthesis of polyether polyol:

[0047] A) 700g of polyglycerol with a molecular weight of 700g / mol is mixed with 1.5g of the above-mentioned emulsion bimetallic catalyst respectively, heated to 100℃, and stirred until the material is uniformly dispersed, the temperature is kept at 100℃, and the material is dehydrated under vacuum stirring for 1h;

[0048] B) heated to 130℃, the reactor is filled with nitrogen to normal pressure, 60g of propylene oxide is added, the pressure change is observed and the time required for the pressure to drop to normal pressure is calculated as the activation time;

[0049] C) after the pressure drops to normal pressure, 2300g of propylene oxide is continuously added to the reaction container, the reaction temperature is controlled at 140℃, and the pressure is 0.3MPa (measured by table pressure), the time required from the completion of the addition of propylene oxide until the reaction pressure no longer decreases is calculated as the reaction time.

[0050] D) The reactor is pumped to negative pressure to remove unreacted propylene oxide, and the polyether polyol product is obtained.

[0051] Example 2

[0052] 1) Preparation of bimetallic liquid phase catalyst:

[0053] A) 25 g of zinc chloride, 5 g of iron hydroxide, 13 g of magnesium hydroxide, and 70 g of wash recovery liquid are mixed together and stirred until uniform; 25 g of potassium hexacyanocobaltate is mixed with 50 g of wash recovery liquid, and the mixture is added dropwise to the reaction liquid, with a dropwise addition time of 60 minutes; 65 g of wash recovery liquid, 70 g of t-butyl alcohol, and 7 g of polyether 204 are stirred until uniform, and then added to the reaction liquid to obtain a crude catalyst product.

[0054] B) The crude catalyst product is centrifuged at 3000 rpm for 15 min to obtain a solid, and t-butyl alcohol and water are mixed in a ratio of 1:3 to obtain a wash liquid; the wash liquid is mixed with the obtained solid to dissolve the potassium ions in the solid, and then centrifuged to obtain a solid, and the wash recovery liquid is recovered; new wash liquid is added to continue dissolving the potassium ions in the solid, and the above operation is repeated multiple times until the potassium ion test in the wash recovery liquid after centrifugation is less than 100 ppm; the potassium ion qualified solid obtained by centrifugation is mixed with polyether with a molecular weight of 700 in a mass ratio of 1:5 to obtain a final new emulsion catalyst.

[0055] 2) Synthesis of polyether polyol:

[0056] A) 700 g of polyglycerol with a molecular weight of 700 g / mol is mixed with 1.5 g of the above emulsion bimetallic catalyst as a starter, heated to 100°C, and stirred until the material is uniformly dispersed; the temperature is maintained at 100°C, and the material is dehydrated under vacuum for 1 h while stirring;

[0057] B) The temperature is raised to 130°C, the reactor is filled with nitrogen to normal pressure, 60 g of propylene oxide is added, the pressure change is observed, and the time required for the pressure to drop to normal pressure is calculated as the activation time;

[0058] C) After the pressure drops to normal pressure, 2300 g of propylene oxide is continuously added to the reaction vessel, and the reaction temperature is controlled at 140°C and the pressure is controlled at 0.3 MPa (gauge pressure) during the reaction; the time required from the completion of propylene oxide addition to the point where the reaction pressure no longer decreases is calculated as the reaction time.

[0059] D) The reactor is pumped to negative pressure to remove unreacted propylene oxide, and the polyether polyol product is obtained.

[0060] Example 3

[0061] 1) Preparation of bimetallic liquid phase catalyst:

[0062] A) 40 g of zinc chloride, 15 g of copper hydroxide, 15 g of aluminum hydroxide, 100 g of wash recovery liquid are mixed together and stirred uniformly; 26 g of potassium hexacyanocobaltate is mixed uniformly with 10 g of wash recovery liquid, and is added dropwise to the reaction liquid, with a dropwise addition time of 45 minutes; 60 g of wash recovery liquid is stirred uniformly with 75 g of t-butyl alcohol and 20 g of polyether 305, and is added to the reaction liquid to obtain a crude catalyst.

[0063] B) The above crude catalyst is centrifuged at 5000 rpm for 20 min to obtain a solid, t-butyl alcohol and water are mixed in a ratio of 1:3 to prepare a wash liquid, the wash liquid is mixed uniformly with the obtained solid to dissolve potassium ions in the solid, and then centrifugation is performed to obtain a solid, the wash recovery liquid is recovered, new wash liquid is added to continue dissolving potassium ions in the solid, and the above operation is repeated multiple times until the potassium ion test in the wash recovery liquid after centrifugation is less than 5 ppm; then the potassium ion qualified solid obtained by centrifugation is mixed uniformly with a polyether with a molecular weight of 700 in a mass ratio of 1:5 to obtain a final new emulsion catalyst.

[0064] 2) Synthesis of polyether polyol:

[0065] A) 700 g of polyglycerol with a molecular weight of 700 g / mol is mixed with 1.5 g of the above emulsion bimetallic catalyst as a starter, heated to 100°C, and stirred until the material is uniformly dispersed, the temperature is maintained at 100°C, and the material is dehydrated under vacuum for 1 h;

[0066] B) The temperature is raised to 130°C, the reactor is filled with nitrogen to normal pressure, 60 g of propylene oxide is added, the pressure change is observed, and the time taken for the pressure to drop to normal pressure is calculated as the activation time;

[0067] C) After the pressure drops to normal pressure, 2300 g of propylene oxide is continuously added to the reaction vessel, the reaction temperature is controlled at 140°C, and the pressure is controlled at 0.3 MPa (gauge pressure), the time taken from the completion of the addition of propylene oxide until the reaction pressure no longer decreases is calculated as the reaction time.

[0068] D) The reaction kettle is evacuated to remove unreacted propylene oxide to obtain a polyether polyol product.

[0069] Example 4

[0070] 1) Preparation of bimetallic liquid phase catalyst:

[0071] A) 30 g of zinc sulfate, 10 g of ferrous hydroxide, 10 g of calcium hydroxide, and 80 g of wash recovery liquid are mixed together and stirred uniformly; 50 g of potassium hexacyanocobaltate is mixed uniformly with 80 g of wash recovery liquid, and is added dropwise to the reaction liquid, with a dropwise addition time of 100 minutes; 25 g of wash recovery liquid is stirred uniformly with 72 g of t-butyl alcohol and 3 g of polyether 204, and is added to the reaction liquid to obtain a crude catalyst.

[0072] B) The above-mentioned catalyst crude product is centrifuged at 4000 rpm for 5 min to obtain a solid, and t-butyl alcohol and water are mixed in a ratio of 1:3 to prepare a washing solution. The washing solution is mixed with the obtained solid to dissolve potassium ions in the solid, and then centrifuged to obtain a solid. The washing solution is recovered, and new washing solution is added to continue dissolving potassium ions in the solid. The above operation is repeated multiple times until the potassium ion test in the recovered washing solution after centrifugation is less than 500 ppm. Then, the potassium ion qualified solid obtained by centrifugation is mixed with a polyether with a molecular weight of 700 in a mass ratio of 1:5 to obtain a final new emulsion catalyst.

[0073] 2) Synthesis of polyether polyol:

[0074] A) 700 g of polyglycerol with a molecular weight of 700 g / mol is mixed with 1.5 g of the above-mentioned emulsion bimetallic catalyst as a starter, heated to 100°C, and stirred until the material is uniformly dispersed. The temperature is maintained at 100°C, and the material is stirred under vacuum for 1 h to remove water.

[0075] B) The temperature is raised to 130°C, the reactor is filled with nitrogen to normal pressure, and 60 g of propylene oxide is added. The pressure change is observed and the time taken for the pressure to drop to normal pressure is calculated as the activation time.

[0076] C) After the pressure drops to normal pressure, 2300 g of propylene oxide is continuously added to the reaction vessel. The reaction temperature is controlled at 140°C, and the pressure is controlled at 0.3 MPa (gauge pressure). The time taken from the completion of propylene oxide addition to the point where the reaction pressure no longer decreases is calculated as the reaction time.

[0077] D) The reaction kettle is evacuated to remove unreacted propylene oxide, and the polyether polyol product is obtained.

[0078] Example 5

[0079] 1) Preparation of bimetallic liquid phase catalyst:

[0080] A) 25 g of zinc acetate, 5 g of zinc hydroxide, 13 g of magnesium hydroxide, and 60 g of washing solution recovery liquid are mixed and stirred uniformly. 30 g of potassium hexacyanocobaltate is mixed with 70 g of washing solution recovery liquid, and then added dropwise to the reaction solution, with a dropwise addition time of 50 minutes. 70 g of washing solution recovery liquid is mixed with 75 g of t-butyl alcohol and 10 g of polyether 204, and then added to the reaction solution to obtain a catalyst crude product.

[0081] B) centrifuge the above catalyst crude product at 3500 rpm for 12 min to obtain a solid, prepare a washing solution of t-butyl alcohol and water in a ratio of 1:3, mix the washing solution with the obtained solid to dissolve the potassium ions in the solid, then centrifuge to obtain a solid, recover the washing solution, continue to dissolve the potassium ions in the solid by adding new washing solution, and repeat the above operation multiple times until the potassium ion test in the recovered washing solution after centrifugation is less than 300 ppm; then mix the potassium ion qualified solid obtained by centrifugation with a polyether with a molecular weight of 700 in a mass ratio of 1:5 to obtain a final new emulsion catalyst.

[0082] 2) Synthesis of polyether polyol:

[0083] A) Mix 700 g of polyglycerol with a molecular weight of 700 g / mol as a starter with 1.5 g of the above emulsion bimetallic catalyst, respectively, heat to 100°C, stir until the material is uniformly dispersed, maintain the temperature at 100°C, and stir under vacuum for 1 h to remove water;

[0084] B) heat to 130°C, fill the reactor with nitrogen to normal pressure, add 60 g of propylene oxide, observe the pressure change and calculate the time taken for the pressure to drop to normal pressure, which is the activation time;

[0085] C) After the pressure drops to normal pressure, continuously add 2300 g of propylene oxide to the reaction vessel, control the reaction temperature at 140°C and the pressure at 0.3 MPa (gauge pressure) during the reaction, and calculate the time taken from the completion of propylene oxide addition until the reaction pressure no longer decreases, which is the reaction time.

[0086] D) Remove unreacted propylene oxide by vacuumizing the reactor to obtain the polyether polyol product.

[0087] Comparative Example 1

[0088] Compared with Example 1, the difference is that no metal hydroxide is added during the synthesis of the catalyst, i.e. only 20 g of zinc chloride is mixed with 50 g of washing solution recovery liquid during the preparation of the bimetallic catalyst; the remaining steps are exactly the same.

[0089] Comparative Example 2

[0090] Compared with Example 1, the difference is that the washing solution recovery liquid is not recycled in the catalyst synthesis process, and the washing solution recovery liquid in Example 1 is completely replaced by water, and the other conditions are exactly the same, finally obtaining an emulsion catalyst, which produces a large amount of washing solution waste liquid.

[0091] The prepared emulsion catalyst is used to synthesize polyether polyol according to the steps of Example 1, and the activation time, reaction time, etc. are recorded.

[0092] Comparative Example 3

[0093] The difference compared with Example 1 is that the comparative example is not configured into an emulsion catalyst after the catalyst synthesis, but is dried and ground to prepare a solid powder catalyst.

[0094] 1) Preparation of a bimetallic solid catalyst:

[0095] A) 20 g of zinc chloride, 8 g of zinc hydroxide, 5 g of iron hydroxide, and 50 g of wash liquor were mixed together and stirred until uniform; 20 g of potassium hexacyanocobaltate was mixed uniformly with 30 g of wash liquor, and was added dropwise to the reaction solution, with a dropwise addition time of 15 minutes; 60 g of wash liquor was uniformly mixed with 65 g of t-butyl alcohol and 5 g of polyether 305, and was added to the reaction solution to obtain a crude catalyst.

[0096] B) The crude catalyst described above was centrifuged at 4000 rpm for 10 min using a centrifuge to obtain a solid, t-butyl alcohol and water were mixed in a ratio of 1:3 to prepare a wash solution, the wash solution was mixed uniformly with the obtained solid to dissolve potassium ions in the solid, and then centrifugation was performed to obtain a solid, the wash solution was recovered, and new wash solution was added to continue dissolving potassium ions in the solid, and the above operations were repeated multiple times until the potassium ion test in the wash solution recovery liquid after centrifugation was less than 20 ppm; the potassium ion qualified solid obtained by centrifugation was then placed in a 120°C vacuum oven for dehydration and drying for 5 h, and then the dried solid was ground into a powder to obtain a solid powder catalyst.

[0097] 2) Synthesis of a polyether polyol:

[0098] A) 700 g of a polyglycerol with a molecular weight of 700 g / mol was mixed with 0.25 g of the above solid powder catalyst as a starter, and was heated to 100°C and stirred until the material was uniformly dispersed, and the temperature was maintained at 100°C, and the material was stirred under vacuum for 1 h to remove water;

[0099] B) The temperature was increased to 130°C, the reaction kettle was filled with nitrogen to atmospheric pressure, 60 g of propylene oxide was added, the pressure change was observed, and the time taken for the pressure to drop to atmospheric pressure was calculated as the activation time;

[0100] C) After the pressure dropped to atmospheric pressure, 2300 g of propylene oxide was continuously added to the reaction vessel, and the reaction temperature was controlled at 140°C and the pressure was controlled at 0.3 MPa (gauge pressure) during the reaction, and the time taken from the completion of the addition of propylene oxide until the reaction pressure no longer decreased was calculated as the reaction time.

[0101] D) The reaction kettle was evacuated to remove unreacted propylene oxide to obtain a polyether polyol product.

[0102] Comparative Example 4

[0103] The difference compared with Example 1 is that an excess of metal hydroxide is added during the synthesis of the catalyst, i.e. 20 g of zinc hydroxide and 20 g of iron hydroxide are added during the preparation of the bimetallic catalyst, and the remaining steps are exactly the same.

[0104] Table 1 is the test result of the bimetallic catalyst of the examples and the comparative examples. The particle size of the catalyst is tested by using the LT 3600Plus instrument of Zhuhai Zhenli Optical Instrument Co., Ltd., and the viscosity of the catalyst emulsion at 25℃ is tested by using the Brookfield rotational viscometer of Shanghai Changji Geological Instrument Co., Ltd.

[0105] Table 1 is the test result of the bimetallic catalyst of the examples and the comparative examples. The particle size of the catalyst is tested by using the LT 3600Plus instrument of Zhuhai Zhenli Optical Instrument Co., Ltd., and the viscosity of the catalyst emulsion at 25℃ is tested by using the Brookfield rotational viscometer of Shanghai Changji Geological Instrument Co., Ltd.

[0106] Particle size D50 (pm) Viscosity (cp @ 25°C) Example 1 93 186 Example 2 86 167 Example 3 97 153 Example 4 80 178 Example 5 78 153 Comparative Example 1 125 172 Comparative Example 2 96 194 Comparative Example 3 103 / Comparative Example 4 129 182

[0107] As can be seen from Table 1, the particle size of the catalyst can be effectively reduced by adding metal hydroxide, the viscosity of the obtained emulsion bimetallic catalyst at 25℃ is less than 200 cp, and the catalyst has good fluidity, which is convenient for adding to the subsequent polymerization reaction system and avoids powder pollution.

[0108] Table 2 is the test result of the catalyst synthesis polyether polyol product of the examples and the comparative examples. The unsaturation degree is tested according to GB / T12008.6-2010 Polyether Polyols Part 6: Determination of Unsaturation Degree, and the PDI is tested according to GB / T12008.3-2009 Polyether Polyols Part 3: Determination Method of Product Molecular Weight Distribution. The results are shown in Table 2.

[0109] Table 2 is the test result of the catalyst synthesis polyether polyol product of the examples and the comparative examples. The unsaturation degree is tested according to GB / T12008.6-2010 Polyether Polyols Part 6: Determination of Unsaturation Degree, and the PDI is tested according to GB / T12008.3-2009 Polyether Polyols Part 3: Determination Method of Product Molecular Weight Distribution. The results are shown in Table 2.

[0110] Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Activation time (min) 3.6 3.1 4.2 3.8 3.9 5.3 5.8 6.5 5.5 Reaction time (min) 150 135 180 165 170 213 240 300 225 PDI 1.02 1.01 1.03 1.01 1.02 1.12 1.15 1.16 1.14 Unsaturation 0.003 0.003 0.003 0.003 0.002 0.004 0.006 0.004 0.005

[0111] As can be seen from Table 2, the catalyst can be better dispersed in the reaction system, the catalyst activation time is short, the catalytic activity is high, and the reaction period is short when the same polyether polyol is prepared by using the novel emulsion bimetallic catalyst of the application. Figure 1 、 Figure 2 As can be seen from Table 2, the catalyst can be better dispersed in the reaction system, the catalyst activation time is short, the catalytic activity is high, and the reaction period is short when the same polyether polyol is prepared by using the novel emulsion bimetallic catalyst of the application.

[0112] Although the content of the application has been described in detail by the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the application. Those skilled in the art can understand that some modifications or adjustments can be made to the application under the guidance of the present description. These modifications or adjustments should also be within the scope defined by the claims of the application.

Claims

1. A method for preparing a bimetallic liquid-phase catalyst, characterized in that, Includes the following steps: 1) The zinc raw material, metal hydroxide 1, metal hydroxide 2 and part of the washing liquid recovery liquid are thoroughly stirred in proportion to obtain a mixed solution. The cobalt raw material is mixed with another part of the washing liquid recovery liquid and added dropwise to the above mixed solution within a certain period of time to obtain the catalyst precursor. 2) Add a certain proportion of the washing liquid recovery liquid, along with ligand X and ligand Y, to the catalyst precursor prepared in step 1) and stir thoroughly to obtain crude catalyst. 3) After centrifuging the crude catalyst obtained in step 2), a solid is obtained. Ligand X and water are mixed in a ratio of 1:3 to prepare a washing solution. The washing solution is mixed with the obtained solid to dissolve potassium ions in the solid. Then, the solid is obtained by centrifugation. The washing solution is recovered. New washing solution is added to continue to dissolve potassium ions in the solid. The above operation is repeated until the potassium ion content in the recovered washing solution after centrifugation is below 500 ppm, which is considered as qualified for the test. 4) The potassium ion qualified catalyst obtained in step 3) is mixed with the multifunctional intermediate in a certain proportion to obtain the bimetallic liquid phase catalyst. In step 1), the amount of zinc raw material added is 20-40 parts; the amount of cobalt raw material added is 20-50 parts; the amount of metal hydroxide 1 added is 5-15 parts; and the amount of metal hydroxide 2 added is 5-15 parts. Metal hydroxide 1 is selected from one or more of ferric hydroxide, ferrous hydroxide, zinc hydroxide, and copper hydroxide; Metal hydroxide 2 is selected from one or more of calcium hydroxide, magnesium hydroxide, and aluminum hydroxide; The ligand X is tert-butanol; The ligand Y is selected from one or more polyethers; In step 4), the multifunctional intermediate is selected from one or more of polyethers or polyesters.

2. The preparation method according to claim 1, characterized in that, In step 1), the zinc raw material is selected from one or more zinc salts.

3. The preparation method according to claim 2, characterized in that, In step 1), the zinc raw material is selected from one or more of inorganic zinc salts or organic zinc salts; the amount of zinc raw material added is 20-30 parts.

4. The preparation method according to claim 3, characterized in that, In step 1), the zinc raw material is zinc chloride; the amount of zinc raw material added is 25 parts.

5. The preparation method according to claim 1, characterized in that, Metal hydroxide 1 is iron hydroxide.

6. The preparation method according to claim 5, characterized in that, The amount of metal hydroxide 1 added is 9 parts.

7. The preparation method according to claim 1, characterized in that, Metal hydroxide 2 is calcium hydroxide.

8. The preparation method according to claim 7, characterized in that, The amount of metal hydroxide 2 added was 13 parts.

9. The preparation method according to claim 1, characterized in that, In step 1), the amount of washing liquid recovery solution required for preparing the mixture is 50-100 parts.

10. The preparation method according to claim 9, characterized in that, The amount of washing liquid recovery solution required for preparing the mixture in step 1) is 70 parts.

11. The preparation method according to claim 1, characterized in that, The cobalt raw material is selected from one or more of cobalt-containing cyanides or cyanide-containing cobalt salts.

12. The preparation method according to claim 11, characterized in that, The cobalt raw material is selected from one or more cobalt salts containing cyanide; the amount of cobalt raw material added is 20-30 parts.

13. The preparation method according to claim 12, characterized in that, The cobalt raw material is potassium hexacyanocobalaminate; the amount of cobalt raw material added is 26 parts.

14. The preparation method according to claim 1, characterized in that, The amount of the other washing liquid recovered liquid mixed with the cobalt raw material is 10-80 parts.

15. The preparation method according to claim 14, characterized in that, The amount of the other washing liquid recovery liquid mixed with the cobalt raw material is 50 parts.

16. The preparation method according to any one of claims 1-8, characterized in that, In step 1), the time for adding the mixed solution of cobalt raw material and another part of the washing liquid recovery solution to the mixed solution is 15-100 min.

17. The preparation method according to claim 16, characterized in that, In step 1), the time for adding the mixed solution of cobalt raw material and another part of the washing liquid recovery solution to the mixed solution is 20-60 minutes.

18. The preparation method according to claim 17, characterized in that, In step 1), the time for adding the mixed solution of cobalt raw material and another part of the washing liquid recovery solution to the mixed solution is 45 minutes.

19. The preparation method according to claim 1, characterized in that, The ligand Y is polyether 204 and / or polyether 305.

20. The preparation method according to any one of claims 1-8, characterized in that, In step 2), the amount of ligand X added is 50-100 parts.

21. The preparation method according to claim 20, characterized in that, In step 2), the amount of ligand X added is 65-75 parts.

22. The preparation method according to claim 21, characterized in that, In step 2), the amount of ligand X added is 70 parts.

23. The preparation method according to claim 20, characterized in that, In step 2), the amount of ligand Y added is 3-20 parts.

24. The preparation method according to claim 23, characterized in that, In step 2), the amount of ligand Y added is 5-10 parts.

25. The preparation method according to claim 24, characterized in that, In step 2), the amount of ligand Y added is 7 parts.

26. The preparation method according to claim 20, characterized in that, In step 2), the amount of washing liquid recovery solution added is 25-70 parts.

27. The preparation method according to claim 26, characterized in that, In step 2), the amount of washing liquid recovery solution added is 30-65 parts.

28. The preparation method according to claim 27, characterized in that, In step 2), the amount of washing liquid recovery solution added is 60 parts.

29. The preparation method according to any one of claims 1-8, characterized in that, In step 3), centrifugation is performed using a high-speed centrifuge with a centrifugation rate of 3000-5000 r / min and a centrifugation time of 5-20 minutes.

30. The preparation method according to claim 29, characterized in that, The centrifugation rate was 4000 r / min; the centrifugation time was 10 minutes.

31. The preparation method according to claim 1, characterized in that, In step 3), a potassium ion content of 5-300 ppm in the recovered washing solution is considered to be qualified for the test.

32. The preparation method according to any one of claims 1-8, characterized in that, In step 4), the multifunctional intermediate is one or more polyethers.

33. The preparation method according to claim 32, characterized in that, In step 4), the multifunctional intermediate is a polyether with two functionalities and a molecular weight of 700.

34. The preparation method according to claim 32, characterized in that, In step 4), the mass ratio of the qualified potassium ion catalyst to the multifunctional intermediate is 1:1 to 1:

10.

35. The preparation method according to claim 34, characterized in that, In step 4), the mass ratio of the qualified potassium ion catalyst to the multifunctional intermediate is 1:

5.

36. The bimetallic liquid-phase catalyst prepared by the method according to any one of claims 1-35, characterized in that, The catalyst particles have a particle size of 100±20μm and a potassium ion content of less than 500ppm.

37. The bimetallic liquid-phase catalyst according to claim 36, characterized in that, The potassium ion content is 5-300 ppm.

38. A method for preparing polyether polyols, characterized in that, The method includes the step of preparing polyether polyols using a polyether with a molecular weight greater than 500 as an initiator, in the presence of a bimetallic liquid-phase catalyst prepared by any one of claims 1-35.

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