A preparation method of epoxybutane polyether polyol

Abstract

The present invention provides a butylene oxide polyether polyol and a preparation method thereof, the preparation method comprising: 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; introducing the pre-reaction liquid into at least three tubular reaction devices connected in series, adding butylene oxide to each of the tubular reaction devices for reaction, and finally obtaining a crude product after the reaction is completed, and the crude product is post-treated to obtain the butylene oxide polyether polyol. The preparation method provided by the present invention uses a supported double metal cyanide complex catalyst and a catalyst promoter, with the help of a tubular reaction device, and 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 polyether through the coordinated coordination of catalyst and process optimization, and prepares butylene oxide polyether with narrow molecular weight, and the product yield is high.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic synthesis, and relates to a method for preparing polyether polyols, and particularly to an epoxybutane polyether polyol and a method for preparing the same. Background Art

[0002] Polyether polyols are an important class of polymer materials and are key raw materials for synthesizing polyurethanes. Their preparation process mainly involves ring-opening homopolymerization or copolymerization of epoxy monomers. Their unique ether bond (C-O-C) main chain skeleton structure endows the materials with high flexibility, low glass transition temperature and hydrophilicity, and they are widely used in fields such as lubricating oils, adhesives and surfactants, occupying an important position in the field of polymer materials.

[0003] Traditional polyether polyols mostly use propylene oxide or ethylene oxide as the main raw materials, and less are synthesized from epoxybutane. Epoxybutane polyether polyols have an ethyl side chain structure. Compared with ethylene oxide-based polyethers and propylene oxide-based polyethers, they have higher flexibility, lower glass transition temperature and excellent hydrophobic properties. Their products can maintain good elasticity and toughness within a wider temperature range, and can effectively avoid problems such as embrittlement and hardening of materials in low-temperature environments, and can improve the oil solubility of polyether lubricating oils 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 epoxybutane-based polyethers. On the one hand, epoxybutane shows low reactivity during the ring-opening polymerization process, and there are problems such as slow ring-opening polymerization rate and low conversion efficiency; on the other hand, during the preparation process, there are significant chain transfer and oligomer side reaction problems, resulting in problems such as reduced polymer molecular weight, uneven material properties and reduced product purity. Therefore, the problems existing in the existing processes have greatly restricted the development and application of epoxybutane polyether polyols.

[0004] In the prior art, the 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, a preparation method and an application thereof. By carrying out microwave hydrothermal reaction of the double metal cyanide with a ligand for complexation, a catalyst for synthesizing polyether polyols is prepared to improve the catalytic activity of the double metal cyanide, and a polyether polyol with lower unsaturation and a narrower molecular weight distribution is prepared. However, the catalyst prepared by this method is suitable for polyether polyols using propylene oxide or ethylene oxide as raw materials, and there is no major improvement in the catalyst composition, and it lacks applicability to the reaction of synthesizing polyether polyols using epoxybutane.

[0006] CN116836380A discloses a method for preparing polyether and the prepared polyether. In this method, a part of epoxy monomer is first contacted with a catalyst and an initiator for a prepolymerization reaction, and then the other part of the epoxy monomer is added to the mixture obtained in the previous step in a continuous feeding manner for a polymerization reaction. By adding the epoxy monomer in two parts and in a continuous feeding manner, a polyether product with a narrow molecular weight distribution and low unsaturation is prepared. In this method, the epoxy monomer is continuously introduced, and the oligomerization reaction occurring in the reaction kettle is uncontrollable. It can be seen that the molecular weight of the polyether prepared by this 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 an epoxybutane polyether polyol and a preparation method thereof. Summary of the Invention

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

[0009] To achieve the purpose of this invention, the following technical solutions are adopted:

[0010] In the first aspect, the present invention provides a preparation method of epoxybutane polyether polyol, and the preparation method includes the following steps:

[0011] (1) Mix an initiator, a supported double metal cyanide complex catalyst, a catalytic assistant and epoxybutane for a pre-reaction to obtain a pre-reaction liquid;

[0012] (2) Introduce the pre-reaction liquid into at least three series-connected tubular reaction devices, add epoxybutane to each tubular reaction device for reaction, and finally obtain a crude product after the reaction ends. The crude product is post-treated to obtain epoxybutane polyether polyol.

[0013] The preparation method provided by the present invention uses a double metal cyanide complex catalyst as the catalyst. The used double metal cyanide complex catalyst has a large specific surface area and high activity, and is combined with a catalytic assistant to shorten the activation stage time of the catalyst, make the catalyst activation stable, effectively improve the reaction activity and efficiency of the epoxybutane polymerization reaction; by virtue of the structural characteristics of the tubular reaction device, the epoxybutane raw material is added in batches, effectively controlling the concentration of epoxybutane in the material, polymerizing successively, reducing backmixing, reducing the generation of cyclic oligomers, and improving the conversion rate of epoxybutane.

[0014] Preferably, the supported double metal cyanide complex catalyst includes 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 5-20 wt%, for example, it can be 5 wt%, 8 wt%, 10 wt%, 12 wt%, 15 wt%, 18 wt% or 20 wt%, but is not limited to the listed values, and other unlisted values within the numerical range are equally 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, the catalyst can be separated and recovered, enabling the recycling of the catalyst and greatly reducing the catalyst content in the product. 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 includes: 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, the 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 includes any one or a combination of at least two of zinc acetate, zinc chloride or zinc nitrate. Typical but non-limiting combinations include the combination of zinc acetate and zinc chloride, the combination of zinc chloride and zinc nitrate, the combination of zinc acetate and zinc nitrate, or the combination of zinc acetate, zinc chloride and zinc nitrate. Preferably, it is zinc acetate.

[0021] Preferably, the dosage of the organic ligand is 1-100 eq, and the dosage is based on the zinc salt. For example, it can be 1 eq, 5 eq, 10 eq, 20 eq, 30 eq, 40 eq, 50 eq, 60 eq, 80 eq or 100 eq, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable. Preferably, it is 10-50 eq.

[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 equally applicable. Preferably, it is 0.1-0.5 mol / L.

[0023] Preferably, the amount of potassium hexacyanocobaltate is 0.5 - 1.8 eq, and the amount is based on the zinc salt. For example, it can be 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. Other unlisted values within the numerical range are equally 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. Other unlisted values within the numerical range are equally applicable, and preferably it is 0.1 - 0.5 mol / L.

[0025] Preferably, the temperature of the first solution is controlled at 60 - 100 °C. For example, it can be 60 °C, 70 °C, 80 °C, 90 °C or 100 °C, but is not limited to the listed values. Other unlisted values within the numerical range are equally applicable, and preferably it is 80 °C.

[0026] Preferably, the method for mixing the first solution and the second solution is: slowly drop 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 equally applicable, and preferably it is 15 min.

[0028] Preferably, the loading method includes grinding loading and / or deposition loading.

[0029] Preferably, the process of grinding loading is: mix the first solution and the second solution for reaction, then perform solid-liquid separation to obtain the double metal cyanide solid, and mix and grind the double metal cyanide solid with the carrier to obtain the supported double metal cyanide complex catalyst.

[0030] Preferably, when performing grinding loading, 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 equally applicable, and preferably it is 9:1.

[0031] Preferably, the process of depositing the load is as follows: adding the carrier into the first solution, then mixing the first solution with the second solution for reaction, and obtaining the supported double metal cyanide complex catalyst after solid-liquid separation.

[0032] Preferably, when depositing the load, the mesh number of the carrier is 50 - 300 meshes, for example, it can be 50 meshes, 100 meshes, 150 meshes, 200 meshes, 250 meshes or 300 meshes, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0033] Preferably, when depositing the load, the dosage of the carrier is 10 - 500 g per mole of zinc salt, for example, it can be 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 equally applicable, and preferably it is 200 g.

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

[0035] Preferably, after solid-liquid separation, it is washed with deionized water.

[0036] Preferably, the initiator in step (1) includes polyol oligomers, and the polyol oligomers include any one or at least two combinations of polyethylene oxide polyether, polypropylene oxide polyether or polybutylene oxide polyether. Typical but non-limiting combinations include the combination of polyethylene oxide polyether and polypropylene oxide polyether, the combination of polypropylene oxide polyether and polybutylene oxide polyether, the combination of polyethylene oxide polyether and polybutylene oxide polyether, or the combination of polyethylene oxide polyether, polypropylene oxide polyether and polybutylene oxide polyether.

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

[0038] Preferably, the dosage 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 the initiator, 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, and other unlisted values within the numerical range are equally applicable, and preferably it is 0.27 g.

[0039] Preferably, the catalytic assistant in step (1) includes acetylacetone.

[0040] Preferably, the amount of the catalytic promoter in step (1) is 0.05 - 2 g per mole of the 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 unlisted values within the numerical range are equally applicable, and preferably it is 0.27 g.

[0041] Preferably, the mass ratio of butylene oxide to the double metal cyanide complex in the supported double metal cyanide complex catalyst in the pre - reaction of step (1) 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. Other unlisted values within the numerical range are equally applicable, and preferably it is 37:1.

[0042] Preferably, the temperature of the pre - reaction in step (1) is 80 - 150 °C. For example, it can be 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. Other unlisted values within the numerical range are equally applicable, and preferably it is 110 °C.

[0043] Preferably, the time of the pre - reaction in step (1) is 5 - 60 min. For example, it can be 5 min, 10 min, 20 min, 30 min, 40 min, 50 min or 60 min, but is not limited to the listed values. Other unlisted values within the numerical range are equally applicable, and preferably it is 15 min.

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

[0045] Preferably, the addition amount of butylene oxide in any one of the said reactions in step (2) is 15 - 162 eq of the initiator. For example, it can be 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. Other unlisted values within the numerical range are equally applicable.

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

[0047] Preferably, the residence time of any of the reactions in step (2) is 15 - 60 min. For example, it can be 15 min, 20 min, 30 min, 40 min, 50 min, or 60 min. However, it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0048] In the present invention, the feeding rates of the pre - reaction liquid and butylene oxide in each reaction are controlled by metering pumps, so that the materials in each tubular reaction device reach the reaction residence time, and the feeding rate is controlled to make the feeding time of the pre - reaction liquid consistent with that of butylene oxide.

[0049] Preferably, the temperature of the reaction in step (2) is 80 - 150 °C. For example, it can be 80 °C, 90 °C, 100 °C, 110 °C, 120 °C, 130 °C, 140 °C, or 150 °C. However, it is not limited to the listed values, and other unlisted values within the numerical range are equally 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. However, it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0051] In the present invention, forming a temperature gradient between two adjacent reactions 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, it can be 20 °C, 30 °C, 40 °C, 50 °C, or 60 °C. However, it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0053] Preferably, the post - treatment process in step (2) includes: first, performing solid - liquid separation to obtain catalyst solids 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, which 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, it can be 1500, 2000, 5000, 8000, 10000, or 12000. However, it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0056] Preferably, the molecular weight distribution of the butylene oxide polyether polyol is 1.03 - 1.15. For example, it can be 1.03, 1.05, 1.07, 1.10, 1.12 or 1.15, but is not limited to the listed values. Other unlisted values within the numerical range are equally applicable.

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

[0058] The preparation method provided by the present invention combines a supported double metal cyanide complex catalyst and a catalytic assistant. With the aid of a tubular reaction device, a process method of adding butylene oxide raw materials in batches is adopted. Through the synergistic cooperation of catalyst and process optimization, problems such as side reactions and low efficiency in the preparation of butylene oxide polyether are solved, and the preparation of butylene oxide polyether with a narrow molecular weight is achieved, and the product yield is high. Description of the Drawings

[0059] Figure 1 It is a process flow diagram of the preparation method of the butylene oxide polyether polyol provided in Example 1. Detailed Embodiments

[0060] The technical solution of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0061] Preparation Example 1

[0062] This preparation example provides a supported double metal cyanide complex catalyst, and the supported double metal cyanide complex catalyst 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 to a 1 L reaction flask. The amount of acetic acid used is 27.7 eq. Add 300 g of deionized water and stir to dissolve. Heat the solution to 80 °C to obtain a first solution;

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

[0068] (c) Slowly add the second solution to the reaction flask over 5 min. After the addition is complete, continue stirring and keep the temperature constant for 15 min, then cool the reaction flask in a water bath to room temperature to obtain a reaction solution;

[0069] (d) Filter the reaction solution to obtain a white solid, wash it 3 times with deionized water, dry it under vacuum at 80 °C for 12 h, and finally grind it to obtain the double metal cyanide;

[0070] (e) Use a BQM-0.4L ball mill, set it to fine grinding mode, use a stainless steel ball milling tank, with stainless steel balls as the ball milling medium, add 10 g of the double metal cyanide and 90 g of 300-mesh silica gel, and carry out ball milling for 15 min to complete the loading to obtain the supported double metal cyanide complex catalyst.

[0071] Preparation Example 2

[0072] This preparation example provides a supported double metal cyanide complex catalyst, and the supported double metal cyanide complex catalyst 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 the 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 to a 1-L reaction flask. The amount of acetic acid used is 27.7 eq. Add 300 g of deionized water and stir evenly. Heat the solution to 80 °C to obtain a first solution;

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

[0078] (c) Slowly add the second solution to the reaction flask over 5 min. After the addition is complete, continue stirring and keep the temperature constant for 15 min, then cool the reaction flask in a water bath to room temperature to obtain a reaction solution;

[0079] (d) Filter the reaction solution to obtain a white solid, wash it 3 times with deionized water, dry it under vacuum at 80 °C for 12 h, and finally crush it 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 to a 1 L reaction flask, add 300 g of deionized water and stir to dissolve. Heat the solution to 80 °C to obtain a first solution;

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

[0084] (c) Slowly add the second solution to the reaction flask within 5 min. After the addition is completed, continue to stir and keep warm for 15 min, and then cool the reaction flask in a water bath to room temperature to obtain a reaction solution;

[0085] (d) Filter the reaction solution to obtain a white solid, wash it 3 times with deionized water, dry it in vacuo at 80 °C for 12 h, and finally grind it to obtain the double metal cyanide complex catalyst.

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

[0087] Comparative Preparation Example 2

[0088] This comparative preparation example provides a supported double metal cyanide complex catalyst, and the supported double metal cyanide complex catalyst 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-butanol.

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

[0091] The preparation method of the supported double metal cyanide catalyst, compared with Preparation Example 1, replaces acetic acid with tert-butanol in the same equivalent, and the rest are the same as Preparation Example 1.

[0092] Example 1

[0093] This example provides a preparation method of an epoxybutane polyether polyol as Figure 1 shown, and the preparation method includes the following steps:

[0094] (1) In a pre-reactor, 54 g of the supported bimetallic cyanide complex catalyst prepared in Preparation Example 1, 20 g of the auxiliary agent acetylacetone, 8.64 kg of epoxybutane polyether with an average molecular weight of 350, and 200 g of epoxybutane were mixed. Among them, the amount of the bimetallic cyanide complex in the supported bimetallic cyanide complex catalyst was 0.27 g per mole of the initiator, the dosage of the catalytic auxiliary agent was 0.27 g per mole of the bimetallic cyanide complex, and the mass ratio of epoxybutane to the bimetallic cyanide complex was 37:1. The mixture was stirred and heated to 110 °C and maintained for 15 min, then the pressure in the reactor was reduced to below 2 atm, and the heating was turned off to obtain a pre-reaction liquid;

[0095] (2) Calculate the total amount of epoxybutane used in the preparation process according to the target molecular weight of the prepared epoxybutane polyol. After subtracting the amount of epoxybutane used in step (1) from the total amount of epoxybutane, it was divided into three equal parts. The first part of epoxybutane was heated to 110 °C through a first heat exchanger. A metering pump was used to control the feeding rates of the pre-reaction liquid and the first part of epoxybutane. The flow rate of the pre-reaction liquid was 9.6 kg / h, and the flow rate of the first part of epoxybutane was 12.0 kg / h. The pre-reaction liquid and the first part of epoxybutane were mixed through a mixer and then entered a first tubular reactor for reaction. The inner diameter of the first tubular reactor was 20 mm, the length of the first tubular reactor was 25 m, and the reaction residence time was 27.4 min. After flowing out of the first tubular reactor, a first reaction liquid was obtained;

[0096] (3) The second part of epoxybutane was heated to 115 °C through a second heat exchanger. A metering pump was used to control the flow rate of the second part of epoxybutane to be 12.0 kg / h. The first reaction liquid and the second part of epoxybutane were mixed through a mixer and then entered a second tubular reactor for reaction. The inner diameter of the second tubular reactor was 20 mm, the length of the second tubular reactor was 40 m, and the reaction residence time was 26.7 min. After flowing out of the second tubular reactor, a second reaction liquid was obtained;

[0097] (4) The third part of epoxybutane was heated to 120 °C through a third heat exchanger. A metering pump was used to control the flow rate of the third part of epoxybutane to be 12.0 kg / h. The second reaction liquid and the third part of epoxybutane were mixed through a mixer and then entered a third tubular reactor for reaction. The inner diameter of the third tubular reactor was 20 mm, the length of the third tubular reactor was 60 m, and the reaction residence time was 28.8 min. After flowing out of the third tubular reactor, a reaction product was obtained and entered 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 to strip for 3 h at 150 °C and 50 mbar pressure to remove low-boiling impurities in the material, obtaining 115.9 kg of the product epoxybutane polyether, and the residual catalyst was 4.5 ppm.

[0099] In this example, the total amount of epoxy butane used in the preparation process is 108.2 kg.

[0100] Example 2

[0101] This example provides a method for preparing epoxy butane polyether polyol. Compared with Example 1, the supported double metal cyanide complex catalyst is replaced with the supported double metal cyanide complex catalyst prepared in Preparation Example 2 in equal mass, and the rest are the same as in Example 1.

[0102] In this example, a total of 115.8 kg of epoxy butane polyether is obtained as the product, and the residual catalyst is 6.9 ppm.

[0103] Examples 3 - 6

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

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

[0106] Table 1

[0107]

[0108] In Example 3, a total of 110.8 kg of epoxy butane polyether is obtained as the product, the residual catalyst is 4.5 ppm, and there is 5.4 kg of condensate in the stripping condenser. After GC - MS analysis, it is mainly a mixture of epoxy butane cyclic oligomers, and only 6% of epoxy butane monomers.

[0109] In Example 4, a total of 105.9 kg of epoxy butane polyether is obtained as the product, the residual catalyst is 4.2 ppm, and there is 9.9 kg of condensate in the stripping condenser. After GC - MS analysis, it is mainly a mixture of epoxy butane cyclic oligomers, and only 8% of epoxy butane monomers.

[0110] In Example 5, a total of 98.6 kg of epoxy butane polyether is obtained as the product, the residual catalyst is 4.2 ppm, and there is 16.6 kg of condensate in the stripping condenser. After GC - MS analysis, it is mainly a mixture of epoxy butane cyclic oligomers, and only 4% of epoxy butane monomers.

[0111] In Example 6, a total of 109.7 kg of epoxy butane polyether is obtained as the product, the residual catalyst is 4.1 ppm, and there is 6.3 kg of condensate in the stripping condenser. After GC - MS analysis, it is epoxy butane monomers, and only a very small amount of oligomers.

[0112] Examples 7 - 9

[0113] Examples 7-9 respectively provide a method for preparing epoxybutane polyether polyol. Compared with Example 1, the feeding rates of the pre-reaction solution and epoxybutane in steps (2) to (4) are changed. Among them, the feeding rates of the first portion of epoxybutane, the second portion of epoxybutane, and the third portion of epoxybutane are changed simultaneously to keep the feeding rates of the three the same, so as to change the reaction residence time, and the rest are the same as in 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 the obtained epoxybutane polyether product, the residual catalyst is 4.5 ppm, and there is 1.4 kg of condensed and recovered epoxybutane monomer in the stripping condenser.

[0118] In Example 8, a total of 113.5 kg of the obtained epoxybutane polyether product, the residual catalyst is 4.5 ppm, and there is 2.8 kg of condensed and recovered epoxybutane monomer in the stripping condenser.

[0119] In Example 9, a total of 116.1 kg of the obtained epoxybutane polyether product, the residual catalyst is 4.5 ppm.

[0120] Examples 10-12

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

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

[0123] Table 3

[0124]

[0125] In Example 10, a total of 115.9 kg of the obtained epoxybutane polyether product, the residual catalyst is 4.9 ppm.

[0126] In Example 11, a total of 116.0 kg of the obtained epoxybutane polyether product, the residual catalyst is 4.4 ppm.

[0127] In Example 12, a total of 114.7 kg of the obtained epoxybutane polyether product, the residual catalyst is 4.3 ppm, and there is 1.6 kg of condensed and recovered epoxybutane monomer in the stripping condenser.

[0128] Examples 13-17

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

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

[0131] Table 4

[0132]

[0133] In Example 13, a total of 30.1 kg of the obtained epoxybutane polyether product, and the residual catalyst is 4.2 ppm.

[0134] In Example 14, a total of 49.8 kg of the obtained epoxybutane polyether product, and the residual catalyst is 4.1 ppm.

[0135] In Example 15, a total of 79.9 kg of the obtained epoxybutane polyether product, and the residual catalyst is 4.6 ppm.

[0136] In Example 16, a total of 159.4 kg of the obtained epoxybutane polyether product, the residual catalyst is 4.5 ppm, and there is 1.2 kg of condensed and recycled epoxybutane monomer in the stripping condenser.

[0137] In Example 17, a total of 238.2 kg of the obtained epoxybutane polyether product, and the residual catalyst is 4.7 ppm. There is 2.8 kg of condensed and recycled epoxybutane monomer in the stripping condenser.

[0138] Comparative Example 1

[0139] This comparative example provides a method for preparing epoxybutane polyether polyol. The preparation method includes 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 total amount of the obtained product, epoxybutane polyether, was 106.9 kg, the residual catalyst was 4.5 ppm, and the total amount of the condensate in the stripping condenser was 9.1 kg. The condensate was analyzed by GCMS and found to be a mixture of epoxybutane oligomers and 46% epoxybutane monomer.

[0149] In this comparative example, no catalyst promoter was added, resulting in a low degree of activation and low 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 epoxybutane polyether polyol. Compared with Example 1, the supported double metal cyanide complex catalyst was replaced with the double metal cyanide complex catalyst prepared in Comparative Preparation Example 1 in equal mass of double metal cyanide complex, and the rest was the same as in Example 1.

[0152] In this comparative example, the total amount of the obtained product, epoxybutane polyether, was 116.3 kg, and the residual catalyst was 47 ppm.

[0153] Comparative Example 5

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

[0155] In this comparative example, the total amount of the obtained product, epoxybutane polyether, was 115.0 kg, and the residual catalyst was 28.2 ppm.

[0156] Performance Test

[0157] Samples of the polyether polyols prepared in the examples and comparative examples were taken for testing. The number average molecular weight, molecular weight distribution, and the content of the residual catalyst in the samples were measured respectively. Among them, the content of the residual catalyst was calculated based on the content of zinc ions in the tested samples, and the yield of epoxybutane polyether was calculated. The results are listed in Table 5.

[0158] The test methods are as follows:

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

[0160] (2) The content of zinc ions in the samples was detected by ICP-AES (Inductively Coupled Plasma Atomic Emission Spectrometry) according to the 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 preparation method of epoxybutane polyether polyol, characterized in that, The preparation method comprises the following steps: (1) Mix an initiator, a supported double metal cyanide complex catalyst, a catalytic assistant, and epoxybutane for pre-reaction. The initiator includes a polyol oligomer, and the polyol oligomer includes any one or a combination of at least two of polyethylene oxide polyether, polypropylene oxide polyether, or polybutylene oxide polyether. The number average molecular weight of the polyol oligomer is 200 - 1000. The supported double metal cyanide complex catalyst includes a carrier and a double metal cyanide complex supported on the carrier. The organic ligand of the double metal cyanide complex is acetic acid, and the catalytic assistant is acetylacetone to obtain a pre-reaction solution; (2) Introduce the pre-reaction solution into at least three series-connected tubular reaction devices, add epoxybutane to each tubular reaction device for reaction, divide the total amount of epoxybutane to be added according to the number of reactions conducted, and add it to each reaction respectively. The temperature of the reaction is 110 - 150°C. Along the material flow direction, the temperature of the starting reaction of the reaction is 110 - 120°C, and the temperature difference between adjacent reactions forms an increasing temperature difference, and the temperature difference is 1 - 5°C. After the final reaction ends, a crude product is obtained, and the crude product is post-treated to obtain polybutylene oxide 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 - 20 wt%.

3. The preparation method according to claim 2, characterized in that, The preparation method of the supported double metal cyanide complex catalyst includes: 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, the 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, wherein, In step (1), the dosage of the double metal cyanide complex in the supported double metal cyanide complex catalyst is 0.05 - 2 g per mole of the initiator; In step (1), the dosage of the catalytic assistant is 0.05 - 2 g per mole of the divalent metal in the supported double metal cyanide complex catalyst.

5. The preparation method according to claim 1, wherein In step (1), the mass ratio of epoxybutane to the double metal cyanide complex in the supported double metal cyanide complex catalyst in the pre-reaction is (1 - 100):

1.

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

7. The preparation method according to claim 1, characterized in that, In step (2), the addition amount of epoxybutane in any one of the reactions is 15 - 162 eq of the initiator; The reaction residence time of any one of the reactions in step (2) is 15 - 60 min.

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