Epoxy butane polyether polyol and preparation method thereof

Abstract

The invention provides epoxybutane polyether polyol and a preparation method thereof.The preparation method comprises the steps that an initiator, a supported double metal cyanide complex catalyst, a catalytic promoter and epoxybutane are mixed for a pre-reaction, and a pre-reaction solution is obtained; introducing the pre-reaction liquid into at least three tubular reaction devices which are connected in series, adding epoxybutane into each tubular reaction device for reaction, finally obtaining a crude product after the reaction is finished, and performing post-treatment on the crude product to obtain epoxybutane polyether polyol. According to the preparation method provided by the invention, the problems of side reaction, low efficiency and the like in the preparation of the epoxy butane polyether are solved through the combination of the supported double-metal cyanide complex catalyst and the catalytic promoter, by virtue of a tubular reaction device and by adopting a process mode of adding the epoxy butane raw material in batches and through the cooperation of the catalyst and process optimization; the epoxy butane polyether with narrow molecular weight is prepared, and the product yield is high.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis and relates to a method for preparing a polyether polyol, in particular to a butylene oxide polyether polyol and a method for preparing the same. Background Art

[0002] Polyether polyols are an important class of polymer materials and a key raw material for synthesizing polyurethane. Their preparation process is mainly based on the ring-opening homopolymerization or copolymerization of epoxy monomers. Their unique ether bond (COC) main chain skeleton structure gives the material high flexibility, low glass transition temperature and hydrophilicity. They are widely used in lubricants, adhesives, surfactants and other fields, and occupy an important position in the field of polymer materials.

[0003] Traditional polyether polyols are mostly made of propylene oxide or ethylene oxide as the main raw materials, and are rarely synthesized from butylene oxide. Butylene oxide polyether polyols have an ethyl side chain structure. Compared with ethylene oxide-based polyethers and butylene oxide-based polyethers, they have higher flexibility, lower glass transition temperature and excellent hydrophobic properties. Their products can maintain good elasticity and toughness in a wider temperature range, which can effectively avoid the problems of brittleness and hardening of materials under low temperature conditions, improve the oil solubility of polyether lubricants and enhance the water resistance of polyether adhesives. In addition, they have great application potential in protective materials, buffer materials, etc. However, there are some difficulties in the preparation process of butylene oxide-based polyethers. On the one hand, butylene oxide shows low reactivity in the ring-opening polymerization process, and there are problems such as slow ring-opening polymerization rate and low conversion efficiency; on the other hand, there are significant problems of chain transfer and oligomer side reactions in the preparation process, which leads to problems such as reduced polymer molecular weight, uneven material properties, and reduced product purity. Therefore, the problems existing in the existing process greatly limit the development and application of butylene oxide polyether polyols.

[0004] In the prior art, research on the preparation process of polyether polyols mainly focuses on the selection of catalysts and the optimization of the process.

[0005] CN118725278A discloses a double metal cyanide catalyst and its preparation method and application. The catalyst for the synthesis of polyether polyols is prepared by complexing the double metal cyanide with a ligand by microwave hydrothermal reaction, thereby improving the catalytic activity of the double metal cyanide and preparing a polyether polyol with a lower unsaturation and a narrower molecular weight distribution. However, the catalyst prepared by the method is suitable for polyether polyols using propylene oxide or ethylene oxide as raw materials, and there is no significant improvement in the catalyst composition, and it lacks applicability to the reaction of synthesizing polyether polyols using butylene oxide.

[0006] CN116836380A discloses a method for preparing polyether and the prepared polyether, wherein the method first contacts a part of epoxy monomer with a catalyst and an initiator to perform a prepolymerization reaction, and then adds another part of epoxy monomer to the mixture obtained in the previous step in a continuous feeding manner to perform a polymerization reaction. By adding the epoxy monomer in two parts and adding it in a continuous feeding manner, a polyether product with a narrow molecular weight distribution and low unsaturation is prepared. The method continuously passes the epoxy monomer, and the oligomerization reaction generated in the reactor is uncontrollable. It can be seen that the molecular weight of the polyether prepared by the method is small, and the yield needs to be improved.

[0007] In view of the problems existing in the existing process, the present invention provides a butylene oxide polyether polyol and a preparation method thereof. Summary of the invention

[0008] The purpose of the present invention is to provide a method for preparing butylene oxide polyether polyols, using butylene oxide as a reaction raw material, optimizing the preparation process, solving the problems of low efficiency in the existing synthesis of butylene oxide polyether polyols, and preparing butylene oxide polyether polyol products with narrow molecular weight distribution and high degree of polymerization.

[0009] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a method for preparing butylene oxide polyether polyol, the preparation method comprising the following steps:

[0011] (1) mixing an initiator, a supported double metal cyanide complex catalyst, a catalyst promoter and butylene oxide for pre-reaction to obtain a pre-reaction liquid;

[0012] (2) Introducing the pre-reaction liquid into at least three tubular reaction devices connected in series, adding butylene oxide into each of the tubular reaction devices for reaction, and finally obtaining a crude product after the reaction is completed. The crude product is post-treated to obtain butylene oxide polyether polyol.

[0013] The preparation method provided by the present invention uses a double metal cyanide complex catalyst as a catalyst. The double metal cyanide complex catalyst used has a large specific surface area and high activity, and is combined with a catalytic aid to shorten the catalyst activation stage time, make the catalyst activation stable, and effectively improve the reaction activity and efficiency of the butylene oxide polymerization reaction; with the structural characteristics of the tubular reaction device, the butylene oxide raw material is added in batches, the concentration of butylene oxide in the material is effectively controlled, the polymerization is carried out successively, the back mixing is reduced, the generation of cyclic oligomers is reduced, and the butylene oxide conversion rate is improved.

[0014] Preferably, the supported double metal cyanide complex catalyst comprises a carrier and a double metal cyanide complex supported on the carrier.

[0015] Preferably, the organic ligand of the double metal cyanide complex is acetic acid.

[0016] Preferably, in the supported double metal cyanide complex catalyst, the loading amount of the double metal cyanide complex is 5-20wt%, for example, it can be 5wt%, 8wt%, 10wt%, 12wt%, 15wt%, 18wt% or 20wt%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0017] Preferably, the carrier is silica gel.

[0018] In the present invention, by using a silica gel carrier to load the catalyst, after the reaction is completed, the catalyst can be separated and recovered, so that the catalyst can be recycled and the catalyst content in the product can be greatly reduced. When the residual catalyst is less than 50 ppm, the impurity removal step can be omitted.

[0019] Preferably, the preparation method of the supported double metal cyanide complex catalyst comprises: dissolving a zinc salt and an organic ligand to prepare a first solution, dissolving potassium hexacyanocobaltate to prepare a second solution, mixing the first solution, a carrier and the second solution for reaction and loading, and then performing solid-liquid separation to obtain the supported double metal cyanide complex catalyst.

[0020] Preferably, the zinc salt comprises any one of zinc acetate, zinc chloride or zinc nitrate or a combination of at least two thereof, typical but non-limiting combinations include a combination of zinc acetate and zinc chloride, a combination of zinc chloride and zinc nitrate, a combination of zinc acetate and zinc nitrate, or a combination of zinc acetate, zinc chloride and zinc nitrate, preferably zinc acetate.

[0021] Preferably, the amount of the organic ligand is 1-100eq, and the amount is calculated as zinc salt, for example, 1eq, 5eq, 10eq, 20eq, 30eq, 40eq, 50eq, 60eq, 80eq or 100eq, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, preferably 10-50eq.

[0022] Preferably, in the first solution, the concentration of zinc ions is 0.01-1 mol / L, for example, it can be 0.01 mol / L, 0.05 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.8 mol / L or 1 mol / L, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable, preferably 0.1-0.5 mol / L.

[0023] Preferably, the amount of potassium hexacyanocobaltate is 0.5-1.8 eq, and the amount is calculated as zinc salt, for example, 0.5 eq, 0.6 eq, 0.8 eq, 1.0 eq, 1.2 eq, 1.4 eq, 1.5 eq, 1.6 eq or 1.8 eq, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0024] Preferably, in the second solution, the concentration of potassium hexacyanocobaltate is 0.01-1 mol / L, for example, it can be 0.01 mol / L, 0.05 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.8 mol / L or 1 mol / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable, preferably 0.1-0.5 mol / L.

[0025] Preferably, the temperature of the first solution is controlled to be 60-100°C, for example, 60°C, 70°C, 80°C, 90°C or 100°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable, preferably 80°C.

[0026] Preferably, the first solution and the second solution are mixed by slowly dropping the second solution into the first solution.

[0027] Preferably, the reaction time is 0-60 min, for example, it can be 0 min, 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min or 60 min, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, preferably 15 min.

[0028] Preferably, the method of loading comprises grinding loading and / or depositing loading.

[0029] Preferably, the grinding and loading process is: mixing the first solution and the second solution to react, then performing solid-liquid separation to obtain a double metal cyanide solid, and mixing and grinding the double metal cyanide solid with a carrier to obtain the supported double metal cyanide complex catalyst.

[0030] Preferably, when grinding loading is performed, the mass ratio of the carrier to the double metal cyanide is (0.5-20):1, for example, it can be 0.5:1, 1:1, 5:1, 10:1, 15:1 or 20:1, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, preferably 9:1.

[0031] Preferably, the process of the deposition loading is: adding the carrier into a first solution, then mixing the first solution with a second solution to react, and obtaining the supported double metal cyanide complex catalyst after solid-liquid separation.

[0032] Preferably, when deposition loading is performed, the mesh size of the carrier is 50-300 mesh, for example, it can be 50 mesh, 100 mesh, 150 mesh, 200 mesh, 250 mesh or 300 mesh, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0033] Preferably, when deposition loading is performed, the amount of the carrier used is 10-500 g per mole of zinc salt, for example, 10 g, 50 g, 100 g, 150 g, 200 g, 250 g, 300 g, 350 g, 400 g, 450 g or 500 g, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable, preferably 200 g.

[0034] Preferably, the solid-liquid separation method comprises filtration and / or centrifugation.

[0035] Preferably, deionized water is used for washing after the solid-liquid separation.

[0036] Preferably, the initiator in step (1) comprises a polyol oligomer, and the polyol oligomer comprises any one of ethylene oxide polyether, propylene oxide polyether or butylene oxide polyether, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of ethylene oxide polyether and propylene oxide polyether, a combination of propylene oxide polyether and butylene oxide polyether, a combination of ethylene oxide polyether and butylene oxide polyether, or a combination of ethylene oxide polyether, propylene oxide polyether and butylene oxide polyether.

[0037] Preferably, the number average molecular weight of the polyol oligomer is 200-1000, for example, 200, 400, 500, 600, 800 or 1000, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0038] Preferably, the amount of the double metal cyanide complex in the supported double metal cyanide complex catalyst in step (1) is 0.05-2 g per mole of initiator, for example, 0.05 g, 0.1 g, 0.5 g, 1 g, 1.5 g or 2 g, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable, preferably 0.27 g.

[0039] Preferably, the catalyst promoter in step (1) includes acetylacetone.

[0040] Preferably, the amount of the catalyst promoter used in step (1) is 0.05-2 g per mole of double metal cyanide complex in the supported double metal cyanide complex catalyst, for example, it can be 0.05 g, 0.1 g, 0.5 g, 1 g, 1.5 g or 2 g, but is not limited to the listed values. Other values ​​not listed in the numerical range are also applicable, preferably 0.27 g.

[0041] Preferably, the mass ratio of butylene oxide in the pre-reaction of step (1) to the double metal cyanide complex in the supported double metal cyanide complex catalyst is (1-100):1, for example, it can be 1:1, 5:1, 10:1, 30:1, 50:1, 80:1 or 100:1, but is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable, preferably 37:1.

[0042] Preferably, the temperature of the pre-reaction in step (1) is 80-150°C, for example, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C or 150°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable, preferably 110°C.

[0043] Preferably, the pre-reaction time of step (1) is 5-60 min, for example, 5 min, 10 min, 20 min, 30 min, 40 min, 50 min or 60 min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable, preferably 15 min.

[0044] Preferably, the total amount of butylene oxide required to be added in step (2) is divided equally according to the number of reactions to be carried out, and added to each of the reactions respectively.

[0045] Preferably, the amount of butylene oxide added in step (2) in any of the reactions is 15-162 eq of the initiator, for example, 15 eq, 30 eq, 50 eq, 80 eq, 100 eq, 120 eq, 150 eq or 162 eq, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0046] In the present invention, the total amount of butylene oxide used in the preparation method, i.e., the total amount of butylene oxide in the pre-reaction in step (1) and the total amount of all butylene oxide added in step (2), is determined according to the target molecular weight of the prepared polyether polyol.

[0047] Preferably, the reaction residence time of any of the reactions in step (2) is 15-60 min, for example, 15 min, 20 min, 30 min, 40 min, 50 min or 60 min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0048] In the present invention, the feed rates of the pre-reaction liquid and the butylene oxide in each reaction are controlled by a metering pump so that the material in each tubular reaction device reaches the reaction residence time, and the feed rate is controlled so that the feeding time of the pre-reaction liquid is consistent with that of the butylene oxide.

[0049] Preferably, the reaction temperature in step (2) is 80-150°C, for example, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C or 150°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0050] Preferably, in step (2), along the material flow direction, the temperature between adjacent reactions forms an increasing temperature difference, and the temperature difference is 0-5°C, for example, it can be 0°C, 1°C, 2°C, 3°C, 4°C or 5°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0051] In the present invention, a temperature gradient is formed between two adjacent reactions, which can effectively improve the reaction efficiency.

[0052] Preferably, in step (2), the temperature of the crude product is controlled to be 20-60°C, for example, 20°C, 30°C, 40°C, 50°C or 60°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0053] Preferably, the post-treatment process in step (2) comprises: firstly performing solid-liquid separation to obtain a catalyst solid and an organic phase, and then stripping the organic phase to obtain butylene oxide polyether polyol.

[0054] In a second aspect, the present invention provides a butylene oxide polyether polyol, wherein the butylene oxide polyether polyol is prepared by the preparation method described in the first aspect.

[0055] Preferably, the molecular weight of the butylene oxide polyether polyol is 1500-12000, for example, 1500, 2000, 5000, 8000, 10000 or 12000, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0056] Preferably, the molecular weight distribution of the butylene oxide polyether polyol is 1.03-1.15, for example, 1.03, 1.05, 1.07, 1.10, 1.12 or 1.15, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] The preparation method provided by the present invention uses a supported double metal cyanide complex catalyst and a catalytic promoter combination, uses a tubular reaction device, adopts a process mode of adding butylene oxide raw materials in batches, and solves the problems of side reactions and low efficiency in the preparation of butylene oxide polyethers through the coordinated coordination of catalysts and process optimization, thereby preparing butylene oxide polyethers with narrow molecular weight and high product yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is a process flow chart of the preparation method of butylene oxide polyether polyol provided in Example 1. DETAILED DESCRIPTION

[0060] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0061] Preparation Example 1

[0062] This preparation example provides a supported double metal cyanide complex catalyst, which includes a carrier and a double metal cyanide complex supported on the carrier.

[0063] The carrier is silica gel, and the organic ligand of the double metal cyanide complex is acetic acid.

[0064] The loading amount of the double metal cyanide complex in the supported double metal cyanide complex catalyst is 10 wt %.

[0065] The preparation method of the supported double metal cyanide complex catalyst is as follows:

[0066] (a) Add 13.2 g of zinc acetate dihydrate (60 mmol) and 100 g of acetic acid in a 1 L reaction bottle, the amount of acetic acid used is 27.7 eq, add 300 g of deionized water and stir to dissolve, and heat the solution to 80° C. to obtain a first solution;

[0067] (b) Take another beaker, add 9.96 g potassium hexacyanocobaltate (30 mmol), the amount of potassium hexacyanocobaltate is 0.5 eq, add 200 g deionized water and stir to dissolve, to obtain a second solution;

[0068] (c) slowly adding the second solution into the reaction flask over 5 minutes, stirring and keeping warm for 15 minutes after the addition is completed, and then cooling the reaction flask to room temperature in a water bath to obtain a reaction solution;

[0069] (d) filtering the reaction solution to obtain a white solid, washing it with deionized water for three times, drying it under vacuum at 80° C. for 12 h, and finally grinding it to obtain the double metal cyanide;

[0070] (e) Using a BQM-0.4L ball mill, set to fine grinding mode, using a stainless steel ball milling jar, and using stainless steel balls as the ball milling medium, 10 g of the double metal cyanide and 90 g of 300 mesh silica gel were added, and ball milling was continued for 15 minutes to complete the loading, thereby obtaining the supported double metal cyanide complex catalyst.

[0071] Preparation Example 2

[0072] This preparation example provides a supported double metal cyanide complex catalyst, which includes a carrier and a double metal cyanide complex supported on the carrier.

[0073] The carrier is silica gel, and the organic ligand of the double metal cyanide complex is acetic acid.

[0074] The loading amount of double metal cyanide in the supported double metal cyanide complex catalyst is 10 wt %.

[0075] The preparation method of the supported double metal cyanide complex catalyst is as follows:

[0076] (a) Add 13.2 g of zinc acetate dihydrate (60 mmol), 100 g of acetic acid and 120 g of 300 mesh silica gel into a 1 L reaction bottle, the amount of acetic acid used is 27.7 eq, add 300 g of deionized water and stir to mix, and heat the solution to 80° C. to obtain a first solution;

[0077] (b) Take another beaker, add 9.96 g potassium hexacyanocobaltate (30 mmol), the amount of potassium hexacyanocobaltate is 0.5 eq, add 200 g deionized water and stir to dissolve, to obtain a second solution;

[0078] (c) slowly adding the second solution into the reaction flask over 5 minutes, stirring and keeping warm for 15 minutes after the addition is completed, and then cooling the reaction flask to room temperature in a water bath to obtain a reaction solution;

[0079] (d) The reaction solution was filtered to obtain a white solid, which was washed three times with deionized water, dried under vacuum at 80° C. for 12 h, and finally crushed to obtain the supported double metal cyanide complex catalyst.

[0080] Comparative Preparation Example 1

[0081] This comparative preparation example provides a double metal cyanide complex catalyst, and the preparation method is as follows:

[0082] (a) Add 13.2 g of zinc acetate dihydrate (60 mmol) and 100 mL of acetic acid into a 1 L reaction bottle, add 300 g of deionized water and stir to dissolve, and heat the solution to 80° C. to obtain a first solution;

[0083] (b) Take another beaker, add 9.96 g potassium hexacyanocobaltate (30 mmol), add 200 g deionized water and stir to dissolve, to obtain a second solution;

[0084] (c) slowly adding the second solution into the reaction flask over 5 minutes, stirring and keeping warm for 15 minutes after the addition is completed, and then cooling the reaction flask to room temperature in a water bath to obtain a reaction solution;

[0085] (d) The reaction solution is filtered to obtain a white solid, which is washed three times with deionized water, dried under vacuum at 80° C. for 12 h, and finally ground to obtain the double metal cyanide complex catalyst.

[0086] That is, compared with Preparation Example 1, silica gel loading was not performed, and the rest was the same as Preparation Example 1.

[0087] Comparative Preparation Example 2

[0088] This comparative preparation example provides a supported double metal cyanide complex catalyst, which includes a carrier and a double metal cyanide complex supported on the carrier.

[0089] The carrier is silica gel, and the organic ligand of the double metal cyanide complex is tert-butyl alcohol.

[0090] The loading amount of the double metal cyanide complex in the supported double metal cyanide complex catalyst is 10 wt %.

[0091] Compared with Preparation Example 1, the preparation method of the supported double metal cyanide catalyst is the same as Preparation Example 1 except that acetic acid is replaced with tert-butyl alcohol in the same equivalent amount.

[0092] Example 1

[0093] This embodiment provides a Figure 1 The preparation method of butylene oxide polyether polyol shown in the figure comprises the following steps:

[0094] (1) In a pre-reaction kettle, 54 g of the supported double metal cyanide complex catalyst prepared in Preparation Example 1, 20 g of auxiliary agent acetylacetone, 8.64 kg of butylene oxide polyether with an average molecular weight of 350 and 200 g of butylene oxide are mixed, wherein the amount of the double metal cyanide complex in the supported double metal cyanide complex catalyst is 0.27 g per mole of the initiator, the amount of the catalyst auxiliary agent is 0.27 g per mole of the double metal cyanide complex, and the mass ratio of butylene oxide to the double metal cyanide complex is 37:1. The mixture is heated to 110° C. with stirring and maintained for 15 min. After that, the pressure in the kettle is reduced to below 2 atm, and the heating is turned off to obtain a pre-reaction liquid;

[0095] (2) Calculating the total amount of butylene oxide used in the preparation process according to the target molecular weight of the butylene oxide polyether polyol, subtracting the amount of butylene oxide used in step (1) from the total amount of butylene oxide, dividing the mixture into three equal parts, subjecting the first part of butylene oxide to heat exchange in a first heat exchanger to raise the temperature to 110° C., controlling the feeding rates of the pre-reaction liquid and the first part of butylene oxide by a metering pump, wherein the flow rate of the pre-reaction liquid is 9.6 kg / h, and the flow rate of the first part of butylene oxide is 12.0 kg / h, the pre-reaction liquid and the first part of butylene oxide are mixed in a mixer, and then introduced into a first tubular reactor for reaction, wherein the inner diameter of the first tubular reactor is 20 mm, the length of the first tubular reactor is 25 m, the reaction residence time is 27.4 min, and a first reaction liquid is obtained after flowing out of the first tubular reactor;

[0096] (3) The second portion of butylene oxide is heated to 115° C. by a second heat exchanger, and the flow rate of the second portion of butylene oxide is controlled to be 12.0 kg / h by a metering pump. The first reaction liquid and the second portion of butylene oxide are mixed by a mixer and enter a second tubular reactor for reaction. The inner diameter of the second tubular reactor is 20 mm, the length of the second tubular reactor is 40 m, the reaction residence time is 26.7 min, and a second reaction liquid is obtained after flowing out of the second tubular reactor;

[0097] (4) The third portion of butylene oxide is heated to 120° C. by a third heat exchanger, and the flow rate of the third portion of butylene oxide is controlled to be 12.0 kg / h by a metering pump. The second reaction liquid and the third portion of butylene oxide are mixed by a mixer and enter a third tubular reactor for reaction. The inner diameter of the third tubular reactor is 20 mm, the length of the third tubular reactor is 60 m, and the reaction residence time is 28.8 min. The reaction product is obtained after flowing out of the third tubular reactor and enters a storage tank for cooling and storage;

[0098] (5) After the reaction was completed, the catalyst was separated from the reaction product by pressure filtration, and then nitrogen was used for stripping at 150°C and 50 mbar for 3 hours to remove low-boiling impurities in the material, thereby obtaining a total of 115.9 kg of product butylene oxide polyether, with a residual catalyst content of 4.5 ppm.

[0099] In this embodiment, the total amount of butylene oxide used in the preparation process is 108.2 kg.

[0100] Example 2

[0101] This embodiment provides a method for preparing butylene oxide polyether polyol. Compared with Example 1, the supported double metal cyanide complex catalyst is replaced by the supported double metal cyanide complex catalyst prepared in Preparation Example 2, and the rest is the same as Example 1.

[0102] In this example, the obtained product butylene oxide polyether is 115.8 kg in total, and the residual catalyst is 6.9 ppm.

[0103] Embodiment 3-6

[0104] Examples 3-6 respectively provide a method for preparing butylene oxide polyether polyol. Compared with Example 1, the temperature of butylene oxide in step (2) to step (4) is changed, and the rest is the same as Example 1.

[0105] The parameter changes in Examples 3-6 are shown in Table 1.

[0106] Table 1

[0107]

[0108] In Example 3, the obtained product butylene oxide polyether was 110.8 kg in total, the residual catalyst was 4.5 ppm, and there were 5.4 kg of condensate in the stripping condenser. GCMS analysis showed that it was mainly a mixture of butylene oxide cyclic oligomers, with only 6% of butylene oxide monomers.

[0109] In Example 4, the obtained product butylene oxide polyether was 105.9 kg in total, the residual catalyst was 4.2 ppm, and there was 9.9 kg of condensate in the stripping condenser. GCMS analysis showed that it was mainly a mixture of butylene oxide cyclic oligomers, with only 8% of butylene oxide monomers.

[0110] In Example 5, the obtained product butylene oxide polyether was 98.6 kg in total, the residual catalyst was 4.2 ppm, and there were 16.6 kg of condensate in the stripping condenser. GCMS analysis showed that it was mainly a mixture of butylene oxide cyclic oligomers, with only 4% of butylene oxide monomers.

[0111] In Example 6, the obtained product butylene oxide polyether was 109.7 kg in total, the residual catalyst was 4.1 ppm, and there were 6.3 kg of condensate in the stripping condenser. GCMS analysis showed that it was butylene oxide monomer with only a very small amount of oligomers.

[0112] Embodiment 7-9

[0113] Examples 7-9 respectively provide a method for preparing butylene oxide polyether polyol. Compared with Example 1, the feed rates of the pre-reaction liquid and the butylene oxide in steps (2) to (4) are changed, wherein the feed rates of the first portion of butylene oxide, the second portion of butylene oxide and the third portion of butylene oxide are changed simultaneously so that the feed rates of the three portions are kept the same to change the reaction residence time. The rest are the same as Example 1.

[0114] The parameter changes in Examples 7-9 are shown in Table 2.

[0115] Table 2

[0116]

[0117] In Example 7, a total of 115.0 kg of butylene oxide polyether was obtained, the residual catalyst was 4.5 ppm, and 1.4 kg of butylene oxide monomer was condensed and recovered in the stripping condenser.

[0118] In Example 8, the product butylene oxide polyether was 113.5 kg in total, the residual catalyst was 4.5 ppm, and 2.8 kg of butylene oxide monomer was condensed and recovered in the stripping condenser.

[0119] In Example 9, the obtained product butylene oxide polyether totaled 116.1 kg, and the residual catalyst was 4.5 ppm.

[0120] Examples 10-12

[0121] Examples 10-12 respectively provide a method for preparing butylene oxide polyether polyol. Compared with Example 1, the amount of the supported double metal cyanide complex catalyst is changed, and the rest is the same as Example 1.

[0122] The parameter changes in Examples 10-12 are shown in Table 3.

[0123] Table 3

[0124]

[0125] In Example 10, the obtained product butylene oxide polyether totaled 115.9 kg, and the residual catalyst was 4.9 ppm.

[0126] In Example 11, the obtained product butylene oxide polyether totaled 116.0 kg, and the residual catalyst was 4.4 ppm.

[0127] In Example 12, the product butylene oxide polyether was 114.7 kg in total, the residual catalyst was 4.3 ppm, and 1.6 kg of butylene oxide monomer was condensed and recovered in the stripping condenser.

[0128] Examples 13-17

[0129] Examples 13-17 respectively provide a method for preparing a butylene oxide polyether polyol. Compared with Example 1, the feed rate of the pre-reaction liquid is changed and the total amount of butylene oxide added is adjusted to prepare a butylene oxide polyether polyol with a target molecular weight. The feed rates of the first portion of butylene oxide, the second portion of butylene oxide and the third portion of butylene oxide remain unchanged, and the rest are the same as Example 1.

[0130] The parameter changes in Examples 13-17 are shown in Table 4.

[0131] Table 4

[0132]

[0133] In Example 13, the obtained product butylene oxide polyether is 30.1 kg in total, and the residual catalyst is 4.2 ppm.

[0134] In Example 14, the obtained product butylene oxide polyether totaled 49.8 kg, and the residual catalyst was 4.1 ppm.

[0135] In Example 15, the obtained product butylene oxide polyether totaled 79.9 kg, and the residual catalyst was 4.6 ppm.

[0136] In Example 16, a total of 159.4 kg of butylene oxide polyether was obtained, the residual catalyst was 4.5 ppm, and 1.2 kg of butylene oxide monomer was condensed and recovered in the stripping condenser.

[0137] In Example 17, the product butylene oxide polyether was 238.2 kg in total, and the residual catalyst was 4.7 ppm. There were 2.8 kg of condensed and recovered butylene oxide monomers in the stripping condenser.

[0138] Comparative Example 1

[0139] This comparative example provides a method for preparing butylene oxide polyether polyol, and the preparation method comprises the following steps:

[0140] In a 200L reactor, 54g of the supported double metal cyanide complex catalyst prepared in Preparation Example 1, 20g of the auxiliary agent acetylacetone (0.2mol, equivalent to 10eq of zinc ion), 8.64kg of butylene oxide polyether with an average molecular weight of 350 and 200g of butylene oxide were mixed, stirred and heated to 110°C for 15min, and the pressure in the reactor dropped and then cooled and depressurized, then 108.2kg of butylene oxide was added and the reactor was closed again, the materials were stirred and mixed, and the temperature in the reactor was heated to 110°C for reaction. The reaction kettle was opened after the pressure in the kettle dropped to below 2 atm for 80 minutes to obtain a crude product. The crude product was filtered under pressure to separate the catalyst. Nitrogen was used for stripping at 150°C and 50 mbar for 3 hours to remove low-boiling impurities in the material. A total of 110.1 kg of butylene oxide polyether was obtained. The residual catalyst was 4.3 ppm. There was 6.1 kg of condensate in the stripping condenser. GCMS analysis showed that it was mainly a mixture of butylene oxide cyclic oligomers and contained 13% of butylene oxide monomer.

[0141] In this comparative example, butylene oxide was added at one time using a kettle reactor, which resulted in an excessively high concentration of butylene oxide, leading to a large amount of butylene oxide self-polymerization by-products.

[0142] Comparative Example 2

[0143] This comparative example provides a method for preparing butylene oxide polyether polyol. Compared with Example 1, the flow rate of the first portion of butylene oxide is set to 36.1 kg / h, and the flow rates of the second portion of butylene oxide and the third portion of butylene oxide are both set to 0, that is, butylene oxide is not added to the second tubular reactor and the third tubular reactor, and the rest is the same as Example 1.

[0144] In this comparative example, the obtained product butylene oxide polyether totaled 111.9 kg, the residual catalyst was 4.1 ppm, and the condensate in the stripping condenser totaled 4.4 kg. GCMS analysis showed that it was mainly a mixture of butylene oxide cyclic oligomers and contained 22% of butylene oxide monomer.

[0145] In this comparative example, butylene oxide was not added in batches, so that the concentration of butylene oxide in the first tubular reactor was too high, resulting in more cyclic oligomer by-products.

[0146] Comparative Example 3

[0147] This comparative example provides a method for preparing butylene oxide polyether polyol. Compared with comparative example 1, no auxiliary agent acetylacetone is added, and the rest is the same as comparative example 1.

[0148] In this comparative example, the obtained product butylene oxide polyether totaled 106.9 kg, the residual catalyst was 4.5 ppm, and the condensate in the stripping condenser totaled 9.1 kg, which was found to be a mixture of butylene oxide oligomers and 46% of butylene oxide monomers by GCMS analysis.

[0149] In this comparative example, no catalyst aid was added, resulting in low activation degree and activity of the catalyst in the pre-reaction stage, leading to incomplete reaction.

[0150] Comparative Example 4

[0151] This comparative example provides a method for preparing butylene oxide polyether polyol. Compared with Example 1, the supported double metal cyanide complex catalyst is replaced by the double metal cyanide complex catalyst prepared in Comparative Preparation Example 1 according to an equal mass of double metal cyanide complex, and the rest is the same as Example 1.

[0152] In this comparative example, the obtained product butylene oxide polyether totaled 116.3 kg, and the residual catalyst was 47 ppm.

[0153] Comparative Example 5

[0154] This comparative example provides a method for preparing butylene oxide polyether polyol. Compared with Example 1, the supported double metal cyanide complex catalyst is replaced by the supported double metal cyanide complex catalyst prepared in Comparative Preparation Example 2, and the rest is the same as Example 1.

[0155] In this comparative example, the obtained product butylene oxide polyether totaled 115.0 kg, and the residual catalyst content was 28.2 ppm.

[0156] Performance Testing

[0157] The polyether polyols prepared in the examples and comparative examples were sampled and tested, and the number average molecular weight and molecular weight distribution of the samples, as well as the residual catalyst content therein were determined respectively, wherein the residual catalyst content was calculated by measuring the content of zinc ions in the samples, and the yield of butylene oxide polyether was calculated, and the results are listed in Table 5.

[0158] The test method is as follows:

[0159] (1) The number average molecular weight and molecular weight distribution were tested by gel permeation chromatography (GPC).

[0160] (2) The zinc ion content in the sample was detected using ICP-AES (inductively coupled plasma atomic emission spectrometry) in accordance with standard HJ776-2015.

[0161] Table 5

[0162]

[0163]

[0164] As can be seen from Table 5, the butylene oxide polyether prepared by the preparation method provided by the present invention has a narrow molecular weight distribution, the molecular weight distribution can be below 1.15, the product yield is high, and the catalyst can be directly recovered by separation, and the residual amount in the product is extremely small, below 6.9 ppm. In addition, after the reaction product is stripped and separated, only a very small amount of butylene oxide monomer is produced. It can be seen that the reaction is complete during the reaction process, which effectively improves the conversion efficiency of butylene oxide.

[0165] Compared with Example 1, in Examples 3-6, after the reaction temperature was increased, the product yield decreased, and the production of butylene oxide cyclic oligomers increased at higher temperatures; in Examples 7-9, the reaction residence time in the tubular reactor was reduced, resulting in insufficient reaction, increased production of butylene oxide cyclic oligomers, and decreased product yield; in Examples 10-12, the amount of catalyst used had a certain effect on the product yield, and when the amount of catalyst used was too small, the catalytic efficiency decreased; as can be seen from Examples 13-17, the preparation method can effectively achieve the preparation of butylene oxide polyethers with a target molecular weight, and the molecular weight of the prepared butylene oxide polyethers is high, reaching 12,000.

[0166] Compared with Example 1, in Comparative Example 1, butylene oxide was added at one time using a kettle reactor, and the butylene oxide concentration per unit time in the kettle was too high, resulting in more butylene oxide self-polymerization byproducts; in Comparative Example 2, butylene oxide was added at one time in a tubular reactor, so that the concentration of butylene oxide in the first tubular reactor was too high, resulting in more cyclic oligomer byproducts. Compared with Comparative Example 1, in Comparative Example 3, no catalyst additive was used, so that the activation degree and activity of the catalyst in the pre-reaction stage were low, resulting in incomplete reaction. In Comparative Examples 1-3, the stripping condensate of the reaction product contained more butylene oxide monomers. It can be seen that the reaction mode of using a kettle reactor or adding butylene oxide at one time greatly limits the degree of reaction, and the conversion efficiency of butylene oxide is low. Compared with Example 1, in Comparative Example 4, the catalyst is not supported by a carrier, and the catalyst cannot be separated and recovered after the reaction is completed, resulting in excessive zinc in the product and the need for an additional impurity removal step; in Comparative Example 5, the double metal cyanide complex catalyst prepared using tert-butyl alcohol as an organic ligand performs poorly when supported on a silica gel carrier. After the reaction is completed and the catalyst is recovered, the catalyst recovery rate is low, and the residual zinc in the product is high, which not only affects the performance of the polyether product, but also affects the service life of the catalyst.

[0167] In summary, the preparation method provided by the present invention uses a supported double metal cyanide complex catalyst and a catalytic promoter combination, uses a tubular reaction device, adopts a process mode of adding butylene oxide raw materials in batches, and solves the problems of side reactions and low efficiency in the preparation of butylene oxide polyethers through the coordinated coordination of catalysts and process optimization, and prepares butylene oxide polyethers with narrow molecular weight, and the product yield is high.

[0168] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing butylene oxide polyether polyol, characterized in that: The preparation method comprises the following steps: (1) mixing an initiator, a supported double metal cyanide complex catalyst, a catalyst promoter and butylene oxide for pre-reaction, wherein the supported double metal cyanide complex catalyst comprises a carrier and a double metal cyanide complex supported on the carrier, and the organic ligand of the double metal cyanide complex is acetic acid, to obtain a pre-reaction liquid; (2) Introducing the pre-reaction liquid into at least three tubular reaction devices connected in series, adding butylene oxide into each of the tubular reaction devices for reaction, and finally obtaining a crude product after the reaction is completed. The crude product is post-treated to obtain butylene oxide polyether polyol.

2. The preparation method according to claim 1, characterized in that: The carrier includes silica gel; In the supported double metal cyanide complex catalyst, the loading amount of the double metal cyanide complex is 5-20wt%.

3. The preparation method according to claim 2, characterized in that: The preparation method of the supported double metal cyanide complex catalyst comprises: dissolving a zinc salt and an organic ligand to prepare a first solution, dissolving potassium hexacyanocobaltate to prepare a second solution, mixing the first solution, a carrier and the second solution for reaction and loading, and then performing solid-liquid separation to obtain the supported double metal cyanide complex catalyst.

4. The preparation method according to claim 1, characterized in that: The initiator in step (1) comprises a polyol oligomer, wherein the polyol oligomer comprises any one of ethylene oxide polyether, propylene oxide polyether or butylene oxide polyether or a combination of at least two thereof, and the number average molecular weight of the polyol oligomer is 200-1000.

5. The preparation method according to claim 1, characterized in that: The amount of the double metal cyanide complex in the supported double metal cyanide complex catalyst in step (1) is 0.05-2 g per mole of initiator; The catalyst promoter in step (1) is acetylacetone, and the amount of the catalyst promoter used is 0.05-2 g per mole of divalent metal in the supported double metal cyanide complex catalyst.

6. The preparation method according to claim 1, characterized in that: The mass ratio of butylene oxide in the pre-reaction of step (1) to the double metal cyanide complex in the supported double metal cyanide complex catalyst is (1-100):

1.

7. The preparation method according to claim 1, characterized in that: The temperature of the pre-reaction in step (1) is 80-150°C; The pre-reaction time of step (1) is 5-60 minutes.

8. The preparation method according to claim 1, characterized in that: The total amount of butylene oxide required to be added in step (2) is divided equally according to the number of reactions to be carried out, and added to each of the reactions; In step (2), the amount of butylene oxide added in any of the reactions is 15-162 eq of the initiator; The reaction residence time of any of the reactions in step (2) is 15-60 min.

9. The preparation method according to claim 1, characterized in that: The reaction temperature in step (2) is 80-150°C; In step (2), along the direction of material flow, the temperature between adjacent reactions forms an increasing temperature difference, and the temperature difference is 0-5°C.

10. A butylene oxide polyether polyol, characterized in that: The butylene oxide polyether polyol is prepared by the preparation method according to any one of claims 1 to 9; The molecular weight of the butylene oxide polyether polyol is 1500-12000, and the molecular weight distribution is 1.03-1.15.

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