A method for refining a polyether polyol and a polyether polyol obtained by using the refining method

Abstract

The application discloses a refining method of polyether polyol and polyether polyol obtained by the refining method. The refining method comprises the following steps: neutralizing the crude polyether polyol by using a neutralizing agent, and then adsorbing the neutralized polyether polyol by using an adsorbent; and after the adsorption, the polyether polyol is obtained by dehydrating and filtering. The adsorbent has the structure shown in formula (I): xMgO.ySiO2.nH2O (I); wherein, in formula (I), x:y:n=(0.2-0.5):1:(0.1-0.45). The special adsorbent is used in the application, and the polyether polyol with better quality can be obtained without adding water, the dehydration time is shorter, and the production cycle is short, and the energy consumption is low.

Description

Technical Field

[0001] This invention belongs to the field of polyethers, and particularly relates to the purification of polyethers. Specifically, it relates to a method for purifying polyether polyols and the polyether polyols obtained by the purification method. Background Technology

[0002] In the synthesis of small molecule polyethers, the use of alkali metal hydroxides as catalysts results in residual alkali metal catalysts in the product, which affects the product's technical specifications and application performance. Generally, the crude product needs to be refined to remove the catalyst and obtain refined polyether.

[0003] Traditional refining processes for polyether devices typically require the addition of approximately 5% (wt%) of pure water for emulsification, followed by the addition of acid and adsorbent, and then a lengthy dehydration process to form potassium dihydrogen phosphate / sodium crystals. The potassium / sodium ions are then removed by filtration. However, this process results in high energy consumption and a long production cycle due to the long dehydration time.

[0004] For example, Chinese patent CN111763309A discloses a purification method for reducing the aldehyde content and odor of polyether polyols, comprising the following steps: 1) adding 0.1-10.0% water (by mass of the crude polyether polyol) to crude polyether polyol at 25-100°C and mixing thoroughly; 2) adding 0.1-3% adsorbent (by mass of the crude polyether polyol) to the polyether polyol from step 1, wherein the adsorbent is a mixture of synthetic magnesium silicate and activated carbon, controlling the adsorption temperature at 80-130°C, and after adsorption equilibrium, performing pressure filtration and testing the potassium and sodium ion content in the polyether polyol after pressure filtration; 3) repeating step 2 until the potassium and sodium ion content of the polyether polyol is less than the required content; 4) adding the required amount of antioxidant to the polyether polyol from step 3; 5) heating and vacuum dehydration to obtain purified polyether polyol. The method described in this invention can reduce the aldehyde content and odor simultaneously.

[0005] For example, Chinese patent CN104151541A discloses a method for purifying polyether, which includes the following steps:

[0006] (1) Mix water, pH adjuster, alkali metal-containing polyether and solid adsorbent to obtain a mixture with pH of 5-8; (2) Insulate and adsorb; (3) Dehydrate under vacuum; (4) Filter to obtain refined polyether; The solid adsorbent is composed of modified salt and adsorbent matrix, wherein the modified salt is selected from magnesium sulfate, aluminum sulfate, potassium aluminum sulfate, sodium aluminum sulfate, alkali metal sulfate, alkali metal phosphate or alkali metal hydrohalic acid salt; The adsorbent matrix is ​​selected from at least one of alumina, amorphous silica, aluminum silicate or magnesium silicate, and can be used in the refining process of polyether. Summary of the Invention

[0007] To overcome the problems existing in the prior art, the present invention provides a method for purifying polyether polyols and the polyether polyols obtained by the purification method. The present invention uses a special adsorbent to obtain high-quality polyether polyols without adding water, and the dehydration time is short, which has the advantages of short production cycle and low energy consumption.

[0008] One objective of this invention is to provide a method for purifying polyether polyols, comprising: neutralizing crude polyether polyols with a neutralizing agent, and then adsorbing them with an adsorbent to obtain the polyether polyols, wherein the adsorbent has the structure shown in formula (I):

[0009] xMgO·ySiO2·nH2O Formula (I);

[0010] In equation (I), x:y:n = (0.2~0.5):1:(0.1~0.45).

[0011] Preferably, in formula (I), when y = 1: x = 0.2, 0.25, 0.3, 0.35, 0.4, 0.45 or 0.5; n = 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4 or 0.45.

[0012] In a preferred embodiment, in formula (I), x:y:n = (0.2~0.45):1:(0.2~0.4).

[0013] For example, in equation (I), when y = 1: x = 0.2, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.35, 0.4 or 0.45; n = 0.2, 0.25, 0.3, 0.35 or 0.4.

[0014] In a preferred embodiment, the molecular weight of the crude polyether polyol is 100 to 3000.

[0015] In a further preferred embodiment, the molecular weight of the crude polyether polyol is 200 to 1200.

[0016] For example, the molecular weight of the crude polyether polyol is 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, or 2000. However, if the molecular weight is large, exceeding 3000, the system viscosity is high, the anhydrous adsorption effect is poor, and the potassium ion concentration will be high, affecting product quality.

[0017] In a preferred embodiment, the crude polyether polyol contains an alkaline substance.

[0018] In a further preferred embodiment, the alkaline substance is at least one selected from alkali metals, alkali metal hydroxides, alkali metal carbonates, and alkali metal alcoholic organic salts.

[0019] In a further preferred embodiment, the alkali metal compound is selected from at least one of sodium metal, potassium metal, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium methoxide, and potassium methoxide.

[0020] In a preferred embodiment, based on a weight of 100 wt% of the crude polyether polyol, the content of alkaline substances is 0.08 to 3 wt%.

[0021] In a further preferred embodiment, based on a weight of 100 wt% of the crude polyether polyol, the content of alkaline substances is 0.05 to 1 wt%, preferably 0.1 to 0.5%.

[0022] For example, based on 100 wt% of the crude polyether polyol, the content of alkaline substances is 0.05 wt%, 0.08 wt%, 0.1 wt%, 0.15 wt%, 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.35 wt%, 0.4 wt%, 0.45 wt%, 0.5 wt%, 0.55 wt%, 0.6 wt%, 0.65 wt%, 0.7 wt%, 0.75 wt%, 0.8 wt%, 0.85 wt%, 0.9 wt%, 0.95 wt%, or 1 wt%.

[0023] In a preferred embodiment, the crude polyether polyol is prepared in the presence of the alkaline substance.

[0024] Specifically, the crude polyether polyol is obtained as follows: a reaction is carried out using a polyol as a starting agent, the alkaline substance as a catalyst, and an epoxide compound as a monomer to obtain the crude polyether polyol. Preferably, the polyol is selected from at least one of ethylene glycol, propylene glycol, and glycerol, and the epoxide compound is selected from ethylene oxide and / or propylene oxide.

[0025] In a preferred embodiment, the neutralizing agent is selected from acidic substances.

[0026] In a further preferred embodiment, the acidic substance is selected from at least one of phosphoric acid, sulfuric acid, oxalic acid, and oxalic acid.

[0027] In a preferred embodiment, the amount of neutralizing agent is 0.1 to 1 part, based on a weight of 100 parts of the crude polyether polyol.

[0028] In a further preferred embodiment, based on 100 parts by weight of the crude polyether polyol, the amount of the neutralizing agent is 0.15 to 0.8 parts.

[0029] In a preferred embodiment, the neutralization is carried out at 30–100°C.

[0030] In a further preferred embodiment, the neutralization is carried out at 50-100°C.

[0031] For example, the neutralization is carried out at 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, or 100°C.

[0032] In a preferred embodiment, the neutralization process is carried out under stirring.

[0033] In a further preferred embodiment, the neutralization process takes 0.1 to 4 hours, preferably 0.5 to 2 hours.

[0034] For example, the neutralization process can be performed for 0.1h, 0.5h, 0.8h, 1h, 1.2h, 1.5h, 1.8h, 0.1h, 2.5h, 3h, 3.5h, or 4h.

[0035] In a preferred embodiment, the adsorbent is a spherical particle with a porous structure and a specific surface area of ​​300–800 m². 2 / g, apparent volume is 20-40mL / 10g, pore volume is 0.3-1mL / 10g.

[0036] In a further preferred embodiment, the adsorbent is a spherical particle with a porous structure and a specific surface area of ​​400–700 m². 2 / g, apparent volume is 25-35mL / 10g, pore volume is 0.5-0.8mL / 10g.

[0037] For example, the adsorbent is a spherical particle with a porous structure and a specific surface area of ​​300, 400, 500, 600, 700 or 800 m². 2 / g, with apparent volumes of 20, 25, 30, 35 or 40 mL / 10g, and pore volumes of 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1 mL / 10g.

[0038] The adsorbent used in this invention is a white, porous, spherical particle. Its principle is based on the adsorbent's combination with metal ions to form large-particle composite salt crystals with very low solubility in polyether, thus achieving filtration and removal. Simultaneously, its porous structure also contributes to decolorization and deodorization. Using this adsorbent eliminates the need for emulsification with water, significantly reducing dehydration time, shortening the production cycle, and substantially lowering production costs, thereby improving economic efficiency and energy efficiency.

[0039] In a preferred embodiment, the amount of adsorbent used is 0.05 to 2 parts, based on 100 parts by weight of the crude polyether polyol.

[0040] In a further preferred embodiment, based on 100 parts by weight of the crude polyether polyol, the amount of the adsorbent is 0.1 to 0.4 parts.

[0041] For example, based on a weight of 100 parts of the crude polyether polyol, the amount of the adsorbent is 0.05 parts, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, or 1 part.

[0042] In a preferred embodiment, the adsorption is carried out at 60–100°C.

[0043] In a further preferred embodiment, the adsorption is carried out at 70-90°C.

[0044] For example, the adsorption is carried out at 60°C, 70°C, 80°C, 90°C or 100°C.

[0045] In a preferred embodiment, the adsorption treatment is carried out under stirring.

[0046] In a further preferred embodiment, the adsorption treatment time is 0.1 to 4 hours, preferably 0.5 to 2 hours.

[0047] For example, the adsorption treatment time is 0.1h, 0.5h, 0.8h, 1h, 1.2h, 1.5h, 1.8h, 0.1h, 2.5h, 3h, 3.5h or 4h.

[0048] In a preferred embodiment, dehydration and filtration are performed after the adsorption treatment.

[0049] In a further preferred embodiment, nitrogen bubbling is used for dehydration. Specifically, the system is heated under vacuum and the moisture is removed by nitrogen bubbling.

[0050] Through numerous experiments, the inventors discovered that nitrogen bubbling dehydration is more effective and has a shorter dehydration time, while vacuum dehydration alone takes a longer time.

[0051] In addition, the technical solution described in this invention is conducive to the formation of large-particle crystals (such as potassium dihydrogen phosphate crystals) and the adsorbent particles are relatively large, which makes filtration better and the filtration time shorter.

[0052] In a preferred embodiment, the dehydration temperature is above 100°C, preferably 100-150°C.

[0053] In a further preferred embodiment, the dehydration temperature is 100-130°C.

[0054] For example, the dehydration temperature is 100°C, 110°C, 120°C, 130°C, 140°C, or 150°C.

[0055] In a preferred embodiment, the dehydration time is less than or equal to 5 hours, preferably less than or equal to 3 hours.

[0056] In a further preferred embodiment, the product is dehydrated until the moisture content is less than or equal to 0.08 wt%.

[0057] A second objective of this invention is to provide a polyether polyol obtained by the purification method described in one objective of this invention.

[0058] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values; these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. In the following, various technical solutions can, in principle, be combined with each other to obtain new technical solutions, which should also be considered as specifically disclosed herein.

[0059] Compared with the prior art, the present invention has the following beneficial effects:

[0060] (1) It does not require long-term dehydration during the refining process, and has the characteristics of short production cycle and low energy consumption;

[0061] (2) The polyether product obtained by the method described in this invention is relatively pure and contains very low levels of alkaline substances. Detailed Implementation

[0062] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0063] It should also be noted that the various specific technical features described in the following embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the various possible combinations will not be described separately in this invention.

[0064] Furthermore, various embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention. The resulting technical solutions are part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0065] Unless otherwise specified, the raw materials used in the examples and comparative examples are all disclosed in the prior art, such as those that can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0066] In the examples and comparative examples, the moisture content of the polyether was determined by a moisture meter, the potassium ion content was determined by a flame spectrophotometer, and the color was determined by visual comparison with the color of a standard platinum-cobalt colorimetric solution, with the results expressed in "APHA" units.

[0067] Crude polyether product A: Molecular weight 400, is a reaction product of propylene glycol as an initiator and potassium hydroxide as a catalyst, which directly undergoes a ring-opening reaction with propylene oxide. The potassium ion content is 3000 mg / kg.

[0068] Crude polyether product B: molecular weight 600, is a reaction product of random copolymerization of propylene oxide and ethylene oxide with glycerol as the initiator and potassium hydroxide as the catalyst, and the potassium ion content is 2000 mg / kg.

[0069] Crude polyether product C: molecular weight 200, is a reaction product of direct ring-opening reaction with ethylene oxide using glycerol as the initiator and potassium hydroxide as the catalyst, with a potassium ion content of 2500 mg / kg.

[0070] Crude polyether product D: molecular weight 800, is a reaction product of random copolymerization of propylene oxide and ethylene oxide with propylene glycol as the initiator and potassium hydroxide as the catalyst, and the potassium ion content is 1500 mg / kg.

[0071] Examples 1-4 used xMgO·ySiO2·nH2O as the adsorbent shown in formula (I), which was purchased from Zaoyang Company (magnesium silicate adsorbent ZH-AD600N). Its appearance is a white, porous, spherical particle. Specific indicators are shown in Table 1.

[0072] Table 1:

[0073] <![CDATA[Silicon dioxide (SiO₂) %]]> 68 Magnesium oxide (MgO)% 16 <![CDATA[H2O%]]> 15 pH value (5% suspension) 10 <![CDATA[Specific surface area (m 2 / g)]]> 500 Apparent volume (ml / 10g) 30 Pore ​​volume (ml / g) 0.6

[0074] Examples 5 and 6 use xMgO·ySiO2·nH2O as the adsorbent shown in formula (I), which was purchased from Zaoyang Company (magnesium silicate adsorbent ZH-AD100NS). Its appearance is a white, porous, spherical particle. Specific indicators are shown in Table 2.

[0075] Table 2:

[0076] <![CDATA[Silicon dioxide (SiO₂)%]]> 53 Magnesium oxide (MgO)% 15 <![CDATA[H2O%]]> 14 pH value (5% suspension) 10 <![CDATA[Specific surface area (m 2 / g)]]> 500 Apparent volume (ml / 10g) 36 Pore ​​volume (ml / g) 0.6

[0077]

Example 1

[0078] 1000g of crude polyether A containing an alkaline catalyst (0.3%) was added to a neutralization vessel, stirred and heated to 70℃ and kept at that temperature for 1 hour; 7g of 75% phosphoric acid was added, and after stirring for 1 hour, the pH value was measured to be 5.2. 3g of the above-mentioned modified adsorbent was added, and the mixture was stirred and mixed at 70℃ for 0.5 hours. The temperature was then increased, and nitrogen was bubbled under vacuum until the temperature reached 120℃ for dehydration for 3 hours. The moisture content was measured to be 0.05%, and the mixture was filtered to obtain refined polyether 1. The results are shown in Table 3.

[0079]

Example 2

[0080] 1000g of crude polyether B containing 0.2% alkaline catalyst was added to a neutralization vessel and heated to 75°C with stirring for 1 hour. 4.5g of 75% phosphoric acid was added and stirred for 1 hour. The pH value was measured to be 5.4. 1.5g of the modified adsorbent was added and stirred at 75°C for 1 hour. The temperature was then increased, and nitrogen was bubbled under vacuum until the temperature reached 125°C for dehydration for 2 hours. The moisture content was measured to be 0.02%. The product was then filtered to obtain refined polyether 2. The results are shown in Table 3.

[0081]

Example 3

[0082] 1000g of crude polyether C containing an alkaline catalyst (0.25%) was added to a neutralization vessel, stirred and heated to 80℃ and kept at that temperature for 1 hour. 5.9g of 75% sulfuric acid was added, and after stirring for 1 hour, the pH value was measured to be 5.0. 2.5g of the modified adsorbent was added, and the mixture was stirred and mixed at 80℃ for 1 hour. The temperature was then increased, and nitrogen was bubbled under vacuum until the temperature reached 120℃ for dehydration for 2.5 hours. The moisture content was measured to be 0.03%. The mixture was then filtered to obtain refined polyether 3. The results are shown in Table 3.

[0083]

Example 4

[0084] 1000g of crude polyether D containing an alkaline catalyst (0.15%) was added to a neutralization vessel, stirred and heated to 85℃ and kept at that temperature for 1 hour; 3.52g of 75% sulfuric acid was added, and after stirring for 1 hour, the pH value was measured to be 5.0. 1.5g of the above-mentioned modified adsorbent was added, and the mixture was stirred and mixed at 80℃ for 1 hour. The temperature was then increased, and nitrogen was bubbled under vacuum until the temperature reached 125℃ for dehydration for 2 hours. The moisture content was measured to be 0.02%, and the mixture was filtered to obtain refined polyether 4. The results are shown in Table 3.

[0085]

Example 5

[0086] 1000g of crude polyether A containing an alkaline catalyst (0.3%) was added to a neutralization vessel and heated to 60°C with stirring for 2 hours. 7g of 75% phosphoric acid was added and stirred for 2 hours. 4g of the modified adsorbent was added and stirred at 90°C for 1.5 hours. The temperature was then increased, and nitrogen was bubbled under vacuum until the temperature reached 110°C for dehydration for 3 hours. The moisture content was measured to be less than 0.08wt%. The product was then filtered to obtain refined polyether with a potassium ion content of 6mg / Kg.

[0087]

Example 6

[0088] 1000g of crude polyether A containing an alkaline catalyst (0.3%) was added to a neutralization vessel and heated to 90°C with stirring for 0.5h. 7g of 75% phosphoric acid was added and stirred for 1h. 1g of the modified adsorbent was added and stirred and mixed at 60°C for 2h. The temperature was then increased and dehydrated at 130°C for 3h while applying a vacuum and bubbling with nitrogen. The moisture content was measured to be less than 0.08wt%. The product was then filtered to obtain refined polyether with a potassium ion content of 8mg / Kg.

[0089] Comparative Example 1

[0090] 1000g of crude polyether D containing an alkaline catalyst (0.15%) was added to a neutralization vessel and heated to 75°C with stirring for 1 hour. 15g of adsorbent aluminum silicate (Al2SiO5) was added and stirred at 70°C for 0.5 hours. The temperature was then increased, and nitrogen was bubbled under vacuum until the temperature reached 120°C for dehydration for 1 hour. The moisture content was measured to be 0.02%. The product was then filtered to obtain refined polyether 5. The results are shown in Table 3.

[0091] Comparative Example 2

[0092] 1000g of crude polyether C containing 0.25% alkaline catalyst was added to a neutralization vessel and heated to 75℃ with stirring for 1 hour. 20g of adsorbent aluminum silicate (Al2SiO5) was added and stirred at 70℃ for 1 hour. The temperature was then increased, and nitrogen was bubbled under vacuum until the temperature reached 120℃ for dehydration for 1 hour. The moisture content was measured to be 0.01%. The product was then filtered to obtain refined polyether 6. The results are shown in Table 3.

[0093] Comparative Example 3

[0094] 1000g of crude polyether A containing an alkaline catalyst (0.3%) was added to a neutralization vessel, stirred and heated to 70℃ and kept at that temperature for 1 hour. 7g of 75% phosphoric acid was added, and after stirring for 1 hour, the pH value was measured to be 5.2. 3g of commercially available unmodified adsorbent magnesium silicate (MgSiO3) was added, and the mixture was stirred and mixed at 70℃ for 0.5 hours. The temperature was then increased, and nitrogen was bubbled under vacuum until the temperature reached 120℃ for dehydration for 2.5 hours. The moisture content was measured to be 0.05%. The mixture was then filtered to obtain refined polyether 7. The results are shown in Table 3.

[0095] Comparative Example 4

[0096] The process of Example 1 was repeated, except that an equal weight of silica / magnesium oxide composition was used to replace the adsorbent in Example 1, wherein the molar ratio of silica to magnesium oxide in the silica / magnesium oxide composition was 85:10. Comparative Example 4 was dehydrated for 3 hours, yielding polyether 8.

[0097] Comparative Example 5

[0098] The process of Example 1 was repeated, except that an equal weight of magnesium trisilicate (2MgO·3SiO2·nH2O) was used to replace the adsorbent in Example 1. Comparative Example 5 was dehydrated for 3 hours, and polyether 9 was obtained.

[0099] Comparative Example 6

[0100] Repeat the process of Example 1, except that equal weights of sepiolite [Si] are used. 12 Mg8O 30 [(OH)4(OH2)4·8H2O] replaces the adsorbent in Example 1. Comparative Example 6 yields polyether 10.

[0101] Comparative Example 7

[0102] The process of Example 1 was repeated, except that an equal weight of adsorbent [(MgO)] was used. 0.16 The adsorbent in Example 1 was replaced with SiO2·0.5H2O. Comparative Example 7 yielded polyether 11.

[0103] Adsorbent [(MgO)] 0.16 SiO2·0.5H2O] is obtained as follows:

[0104] Aqueous solutions of magnesium sulfate (1.3 mol / L), sulfuric acid (1.3 mol / L), and water glass (No. 3) consisting of Na₂O (0.7 mol / L) and SiO₂ (2.1 mol / L) were prepared separately. 500 mL of water was pre-added to a 1 L stainless steel reactor using an overflow device. While stirring, the reactor was supplied with water at flow rates of 5.5 mL / min, 4.5 mL / min, and 21.3 mL / min using metering pumps, and the reaction was carried out continuously at room temperature for 5 hours. The resulting reaction slurry had a pH of 8.9. The slurry was dehydrated using a suction filter to form a filter cake. The cake was then washed with 0.3 mol / L magnesium sulfate aqueous solution (20 times the weight of the solids in the filter cake). Sodium was removed by ion exchange. The filter cake was then re-emulsified with ion-exchanged water to a concentration of 100 g / L based on solids, yielding 1 L of slurry. The slurry was heated at 120°C for 2 hours while being stirred, then filtered using a suction filter. It was washed with ion-exchanged water at a volume 20 times the weight of the solids in the filter cake, then emulsified to a concentration of 100 g / L and dried using a laboratory spray dryer. The resulting sample underwent powder X-ray diffraction (PXRD) analysis. Although weak, the diffraction pattern still showed a sepiolite-type structure. The BET surface area was 580 m² / g, the Na content was 0.02% by weight, the average particle size was 49 μm, and the composition was (MgO). 0.16 ·Si O2·0.5H2O.

[0105] The potassium ion content in polyether 11 obtained in Comparative Example 7 was 35 mg / kg, which was significantly higher than that in Example 1.

[0106] The inventors conducted further experiments, still using the adsorbent [(MgO)]. 0.16 When the adsorbent in Example 1 was replaced with SiO2·0.5H2O and water was added to the system, the potassium ion removal effect was found to be higher than the result without water. This indicates that the adsorbent is not suitable for the anhydrous treatment system of the present invention when the molar ratio of x, y, and n is not within the range defined by the present invention.

[0107] Table 3:

[0108]

[0109] As shown in Table 3 above, (1) in polyethers 5 and 6, the lack of water and acid for purification resulted in high potassium ion levels, long filtration times, and mixed materials. Water had to be added and the materials were purified again according to conventional methods before they were qualified, which increased the production cycle and energy consumption. (2) in polyether 7, only the potassium ion level was high. It was necessary to add 5g of conventional adsorbent magnesium silicate to bring the potassium ion level within the range. However, after filtration, the filtration time was about 1.5 hours, and the effect was not ideal. (3) in polyether 8, the potassium ion level was high and the filtration time was long. After adding 5g of conventional adsorbent magnesium silicate, it was even more difficult to filter out the material. It was necessary to purify it again according to conventional methods. (4) in polyether 10, the potassium ion level was high, the color was dark, and the filtration time was long. This adsorbent was not suitable.

[0110] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A method for purifying polyether polyols, characterized in that, The refining method includes: the crude polyether polyol is prepared in the presence of an alkaline substance: using a polyol as a starting agent, the alkaline substance as a catalyst, and an epoxide compound as a monomer, a reaction is carried out to obtain the crude polyether polyol, wherein the polyol is selected from at least one of ethylene glycol, propylene glycol, and glycerol; the crude polyether polyol is neutralized with a neutralizing agent selected from an acidic substance; then an adsorbent is used for adsorption treatment; the temperature is initially raised, and dehydration is carried out by bubbling nitrogen while applying vacuum, to obtain the polyether polyol, wherein the adsorbent has the structure shown in formula (I): xMgO·ySiO2·nH2O formula (I); In equation (I), x:y:n = (0.35~0.5):1:(0.1~0.45); The molecular weight of the crude polyether polyol is 200-1200; based on a weight of 100 parts of the crude polyether polyol, the amount of the adsorbent is 0.05-2 parts.

2. The refining method according to claim 1, characterized in that, In equation (I), x:y:n = (0.35~0.45):1:(0.2~0.4).

3. The refining method according to claim 1, characterized in that, The adsorbent is a spherical particle with a porous structure and a specific surface area of ​​300~800 m². 2 / g, apparent volume is 20~40mL / 10g, pore volume is 0.3~1mL / 10g.

4. The refining method according to claim 1, characterized in that, The crude polyether polyol contains alkaline substances.

5. The refining method according to claim 4, characterized in that, The alkaline substance is selected from at least one of alkali metals, alkali metal hydroxides, alkali metal carbonates, and alkali metal alcoholic organic salts; and / or, Based on the weight of the crude polyether polyol being 100 wt%, the content of alkaline substances is 0.08~3 wt%.

6. The refining method according to claim 5, characterized in that, Based on the weight of the crude polyether polyol being 100 wt%, the content of alkaline substances is 0.1~0.5 wt%.

7. The refining method according to claim 1, characterized in that, The neutralizing agent is selected from at least one of phosphoric acid, sulfuric acid, oxalic acid, and oxalic acid.

8. The refining method according to claim 1, characterized in that, Based on the fact that the crude polyether polyol weighs 100 parts, the amount of the neutralizing agent is 0.1 to 0.8 parts.

9. The refining method according to claim 1, characterized in that, Based on the fact that the crude polyether polyol weighs 100 parts, the amount of the neutralizing agent is 0.15 to 0.8 parts.

10. The refining method according to claim 1, characterized in that, The neutralization is carried out at 30~100°C; and / or, The neutralization process takes 0.1 to 4 hours.

11. The refining method according to claim 1, characterized in that, The neutralization is carried out at 50~100°C; and / or, The neutralization process takes 0.5 to 2 hours.

12. The refining method according to claim 1, characterized in that, Based on the fact that the crude polyether polyol weighs 100 parts, the amount of the adsorbent used is 0.1 to 0.4 parts.

13. The refining method according to claim 1, characterized in that, The adsorption is carried out at 60~100℃; and / or, The adsorption treatment time is 0.1~4h.

14. The refining method according to claim 1, characterized in that, The adsorption is carried out at 70-90°C; and / or, The adsorption treatment time is 0.5~2h.

15. The refining method according to any one of claims 1 to 14, characterized in that, The dehydration temperature is above 100℃.

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