Low-aldehyde and low-odor polyether polyol as well as preparation method and application thereof

Abstract

The invention discloses low-aldehyde and low-odor polyether polyol as well as a preparation method and application thereof, the polyether polyol is prepared by adopting a phosphazene catalyst and carrying out polymerization reaction on an active hydrogen compound and oxyalkylene, and the molecular weight is 800-15000; the functionality is 2-6; the formaldehyde content is less than or equal to 0.01 ppm, the acetaldehyde content is less than or equal to 0.01 ppm, the acrolein content is less than or equal to 0.01 ppm, the propionaldehyde content is less than or equal to 0.01 ppm, and the odor grade is less than or The catalyst is prepared by dissolving phosphorus pentahalide in a non-benzene organic solution, reacting with a guanidine compound to obtain an organic phosphonium salt solution, mixing and reacting with an alkali metal salt compound, filtering, drying, performing reduced pressure distillation and purifying. The polyol can be used for preparing a low-odor polyurethane material. The specific phosphazene catalyst is adopted for polymerization reaction, the content of by-products generated due to chain transfer is effectively reduced, and the prepared polyether polyol is low in degree of unsaturation, low in aldehyde content and low in odor.

Description

Technical Field

[0001] The invention relates to a polyol and a preparation method and application thereof, and in particular to a low-aldehyde, low-odor polyether polyol and a preparation method and application thereof. Background Art

[0002] Polyether polyol is an important chemical raw material, widely used in weaving, synthetic leather, adhesives, foam plastics, elastomers and other industrial fields, and is the main raw material for the production of polyurethane. With the enhancement of environmental awareness, volatile organic compounds (VOC) and high odor in polyurethane-related products have become important factors restricting their application. The odor of polyether polyol mainly comes from: (1) aldehydes and ketones produced by oxidation or isomerization in the synthesis of polyether polyol; (2) chain transfer during the growth of polyether polyol chain to produce various molecular weight propylene and allyl polyether polyols, and the decomposition of these by-products under acidic conditions during the refining process to produce propionaldehyde and propionaldehyde condensation products; (3) the odor caused by the addition of low molecular weight, high VOC, and high atomization value antioxidants.

[0003] There are many mature methods in the industry to solve the odor problem of polyether polyols. For example, purification methods such as distillation, stripping, and thin film evaporation can partially reduce the odor of polyether polyols, but it is still impossible to completely remove the high molecular weight propionaldehyde and its condensation compounds in polyether polyols. In the prior art, when the adsorption method is used for refining, magnesium silicate is usually used for adsorption. The particle size of ordinary magnesium silicate is 124μm and the specific surface area is 35m 2 / g, pore volume is 0.8cm 3 / g, the alkalinity is around 10, which is on the high side.

[0004] Patent CN108148192A discloses a method for preparing low-odor polyether polyols, wherein an aldehyde scavenger is added to the polyether polyols, and the aldehyde scavenger reacts with the aldehyde compounds to achieve the purpose of removing the aldehyde compounds, but such scavengers are hydrazine compounds, which are dangerous and not conducive to large-scale industrial production. Patent CN106589345A discloses a method for refining polyether polyols to reduce VOC content and odor, wherein the polyether polyols are prepared by reacting an initiator with an oxidized olefin under the action of an alkali metal catalyst, a self-made adsorbent is added to the polyether polyols for reaction, and the water and low-boiling substances in the polyether polyols are removed by vacuum heating, and the finished product is obtained by filtering after the water content is qualified. The formaldehyde content in the obtained polyether polyols reaches 0.89ug / g, the acetaldehyde content reaches 1.24ug / g, and the acrolein content reaches 0.56ug / g; the process requires multiple operations in the process and also requires the analysis of the water content in the polyols, and the process is relatively complicated. Patent CN108148190A discloses a method for preparing a high-activity, low-volatile polyether polyol, which uses an alkali metal aqueous solution as a catalyst to synthesize a polyether polyol oligomer with high catalytic activity; then a polymerization reaction is performed to obtain a low-volatile polyether polyol crude polymer, and after neutralization and refining treatment, a high-activity, low-volatile polyether polyol is obtained. The formaldehyde content of the polyether polyol prepared in the embodiment is 0.1-1ppm, and the acetaldehyde content is 5-17ppm. The process is subjected to multiple steps such as neutralization, adsorption, crystallization, filtration and separation, which consumes a lot of energy and is complicated, which is not conducive to large-scale industrial production. Patent CN107652426A discloses a refining method for reducing the VOC content and odor in polyether polyols. The formaldehyde content in the polyether obtained by this method can be reduced to 0.10ppm, the acetaldehyde content can be reduced to 0.21ppm, the acrolein content can be reduced to 0ppm, and the odor level can be reduced to 1.0ppm; however, the patent does not explain the results of propionaldehyde. Summary of the invention

[0005] Purpose of the invention: The purpose of the present invention is to provide a low-aldehyde, low-odor polyether polyol, which has a simple preparation process, low odor and low aldehyde content;

[0006] The second object of the present invention is to provide a method for preparing the above-mentioned low-aldehyde, low-odor polyether polyol;

[0007] The third object of the present invention is to provide the application of the low-aldehyde, low-odor polyether polyols mentioned above.

[0008] Technical solution: The low-aldehyde, low-odor polyether polyol of the present invention is prepared by polymerization of active hydrogen compounds and olefin oxides using a phosphazene catalyst, with a molecular weight of 800 to 15,000; a functionality of 2 to 6; the formaldehyde content of the polyether polyol is ≤0.01ppm, the acetaldehyde content is ≤0.01ppm, the acrolein content is ≤0.01ppm, the propionaldehyde content is ≤0.01ppm, and the odor level is ≤3.5. The general structural formula of the phosphazene catalyst is shown in the following formula (I):

[0009]

[0010] In the above general formula (I), X represents an alkali metal salt compound, - represents an alkali metal anion formed by the departure of the metal ion in X; wherein X is selected from one of sodium alkoxide, potassium alkoxide, sodium carboxylate, potassium carboxylate or metal phosphate;

[0011] The continuous preparation method of the phosphazene catalyst comprises the following steps:

[0012] (1) dissolving phosphorus pentahalide in an organic solvent to obtain a phosphorus pentahalide organic solution; slowly dropping a guanidine compound solution into the phosphorus pentahalide organic solution under an inert atmosphere at -15 to 5°C, returning the temperature to room temperature after the dropping is completed, stirring at room temperature, then heating in an oil bath, continuing the reaction, cooling to room temperature after the reaction is completed, filtering to remove precipitates, and obtaining an organic phosphonium salt solution containing the organic solvent and the halogenated phosphorus compound;

[0013] (2) adding an alkali metal salt compound to the organic phosphonium salt solution obtained in step (1), reacting under an inert atmosphere and heating conditions, cooling and filtering after the reaction, and distilling the filtrate under reduced pressure to obtain a crude product of a phosphazene compound;

[0014] The organic solvent is selected from at least one of nitriles or ethers; the alkali metal salt compound is selected from one of sodium alkoxide, potassium alkoxide, sodium carboxylate, potassium carboxylate or metal phosphate.

[0015] Wherein, in the continuous preparation method of the phosphazene catalyst, in step (1), the mass ratio of phosphorus pentahalide to organic solvent is 1:6-12, the reaction temperature is controlled at 0-5°C under nitrogen protection; the molar ratio of phosphorus pentahalide to guanidine compound is 1:5-11; the temperature of oil bath heating is 80-120°C, and the stirring time is 3-8h.

[0016] Wherein, in the continuous preparation method of the phosphazene catalyst, in step (2), the molar ratio of the organic phosphonium salt solution to the alkali metal salt compound is 1:1-2; the reaction time is 3-8h, the reaction temperature is 50°C-80°C; and the reaction pressure is normal pressure.

[0017] Wherein, the phosphorus pentahalide is selected from one of phosphorus pentabromide and phosphorus pentachloride; the guanidine compound is 1,1,3,3-tetramethylguanidine; the organic solvent is selected from at least one of propionitrile, butyronitrile, adiponitrile, propyl ether, butyl ether or 1,4-dioxane; the alkali metal salt compound is selected from at least one of potassium methoxide, sodium methoxide, potassium ethoxide, sodium ethoxide, potassium formate, sodium formate, potassium acetate, sodium acetate, potassium dihydrogen phosphate or sodium dihydrogen phosphate.

[0018] The obtained crude phosphazene catalyst product is recrystallized or slurried for purification:

[0019] The recrystallization step is as follows: recrystallizing the crude phosphazene catalyst product with a purification solvent, filtering, and drying to obtain a white powdery low-odor phosphazene catalyst; the purification solvent is selected from a mixed solution of at least one of nitriles or alcohols and at least one of ethers or alkanes; the volume ratio of at least one of nitriles or alcohols to at least one of ethers or alkanes is 1:2-300;

[0020] The slurrying step is as follows: the crude phosphazene catalyst product is slurried with a purification solvent, filtered, and dried to obtain a white powdery low-odor phosphazene catalyst; the purification solvent is selected from a mixed solution of at least one of nitriles or alcohols and at least one of ethers or alkanes; the volume ratio of at least one of nitriles or alcohols to at least one of ethers or alkanes is 1:2-500.

[0021] The preparation method of the above-mentioned low-aldehyde, low-odor polyether polyol comprises the following steps:

[0022] (1) using a low molecular weight polyether as an initiator, and preparing polyether polyol I by polymerization reaction in the presence of an olefin oxide and a phosphazene catalyst, controlling the reaction temperature to be 90 to 105° C., and the reaction pressure to be ≤0.45 MPa; the amount of the phosphazene catalyst added is 0.15 to 0.35% of the mass of the polyether polyol I;

[0023] (2) Adding a neutralizing agent to the polyether polyol I for acid-base neutralization, stirring for a period of time, and then adding a magnesium silicate adsorbent, wherein the amount of the adsorbent added is 0.1 to 1% of the mass of the polyether polyol I;

[0024] (3) Adding pure water to the polyether polyol I to be purified and continuing to stir for a period of time;

[0025] (4) Heating and vacuum dehydration, and filter pressing to obtain low-aldehyde, low-odor polyether polyols.

[0026] Wherein, in the step (1), the phosphazene catalyst represented by the general formula (I) in claim 1 is mixed with an active hydrogen compound Y and subjected to a heating treatment to obtain a salt of a phosphazene cation represented by the general formula (II) and an anion of an active hydrogen compound;

[0027]

[0028] In the above general formula (II), n is a real number greater than 0 and less than or equal to 8, Y n- It represents the anion of the active hydrogen compound formed by the departure of n protons in the active hydrogen compound Y; Y is a polyether polyol with a functionality of 2 to 8 and a molecular weight of 300 to 2000; n in the general formula (II) is a real number greater than 0 and less than or equal to 1, and Y is a polyether polyol with a functionality of 2 to 6 and a molecular weight of 400 to 1200.

[0029] Wherein, in step (1), the hydroxyl value of the low molecular weight polyether is 200-300 mgKOH / g, the functionality is 2-6, and the molecular weight is 400-1200.

[0030] Wherein, in step (2), the pH value of the material is controlled to be 6-7 by acid-base neutralization, the material temperature is 90-120°C, and the neutralizer is added and stirred for 1-3 hours; after adding the magnesium silicate adsorbent, the material temperature is controlled to be 90-120°C, the pH value is 7-11, and stirred for 1-3 hours.

[0031] Wherein, in step (3), the amount of pure water added is 3 to 15% of the mass of the polyether polyol I to be purified; and stirring is continued for 1 to 3 hours after adding the pure water.

[0032] The above-mentioned low-aldehyde, low-odor polyether polyol is used in the polyurethane industry which has high requirements on odor.

[0033] Beneficial effects: Compared with the prior art, the present invention achieves the following significant effects:

[0034] (1) The present invention provides a low-aldehyde, low-odor polyether polyol. By using the specific phosphazene catalyst of the present invention in the polymerization reaction process, the content of by-products generated by chain transfer can be effectively reduced, and the prepared polyether polyol has low unsaturation. The polyether polyol obtained by the preparation method of the present invention has low aldehyde content and low odor, wherein the formaldehyde content is ≤0.01ppm, the acetaldehyde content is ≤0.01ppm, the acrolein content is ≤0.01ppm, the propionaldehyde content is ≤0.01ppm, and the odor level is ≤3.5. Therefore, the quality level of the polyether polyol can be well improved, and the odor and VOC of the polyurethane foam prepared therefrom can be improved, thereby achieving good technical effects. (2) The present invention adopts a lower temperature to carry out the polymerization reaction when preparing polyether polyols, which can further reduce the unsaturation of polyether polyols, thereby further reducing their odor; (3) The phosphazene catalyst used in the present invention only uses a non-benzene and inert solvent that does not participate in the reaction during the preparation process, and there is no need to frequently change the solvent. By using the same solvent, the steps of extraction and distillation are reduced, thereby reducing energy consumption and the generation of wastewater and waste in the process. Through the preparation method of the continuous phosphazene catalyst, a phosphazene catalyst without benzene series can be efficiently prepared, which also plays a positive role in environmental protection. (4) The phosphazene catalyst of the present invention has been further improved. When the value of n in the general formula (II) is greater than 0 and less than or equal to 1, the proportion of the catalyst in the initiator is small. At the same time, the catalyst maintains a high catalytic activity when catalyzing polyether synthesis, which can not only reduce enterprise costs, but also enhance the efficiency of energy utilization, and play a positive role in social energy conservation and emission reduction. (5) The crude phosphazene catalyst obtained by the present invention is purified by pulping or recrystallization, which can make the phosphazene catalyst have lower odor and higher purity. Most importantly, the preparation process provides strong support for the industrial production of phosphazene catalyst. (6) The purified phosphazene catalyst has low impurity content, which can significantly inhibit small molecular impurities in the subsequently prepared polyols. At the same time, the odor of the prepared polyurethane foam can also be significantly improved. DETAILED DESCRIPTION

[0035] The present invention is described in further detail below.

[0036] The sources of relevant raw materials in various embodiments of the present invention are shown in Table 1 below.

[0037] Table 1 List of raw materials

[0038]

[0039] Example 1

[0040] (1) Preparation of phosphazene catalyst:

[0041] In a 500ml three-necked flask equipped with a stirrer, a thermometer, and a dropping funnel, 10g of phosphorus pentachloride and 90g of propionitrile solution were added, and 46g of tetramethylguanidine was slowly added dropwise under nitrogen protection, and the reaction temperature was controlled at about 0°C. After the addition was completed, the temperature was slowly restored to room temperature, stirred at room temperature for 0.5h, and transferred to an oil bath, stirred at 110°C for 3h, cooled to room temperature, and filtered to remove the precipitate. 3.7g of potassium methoxide was added to the obtained solution, reacted at 60°C for 3h, cooled to room temperature, and filtered, the filtrate was collected and the solvent was removed by reduced pressure distillation, and the concentrated solution was recrystallized from acetonitrile and cyclohexane, wherein the volume ratio of acetonitrile to cyclohexane was 1:50, filtered, and dried to obtain 19.4g of a white powder catalyst; the yield was 78%. The structural formula of the obtained phosphazene catalyst is shown in the above formula (I).

[0042] (2) Preparation of low-aldehyde, low-odor polyether polyols:

[0043] 120g of low molecular weight polyether 1 and 2.25g of the above-mentioned 0.15% phosphazene catalyst were added to a 2L autoclave, replaced with nitrogen three times, and degassed at 105°C and -0.09Mpa for 2h. At this time, the value of n in the general formula (II) is 0.025. At a pressure of -0.09Mpa and a temperature of 95°C in the autoclave, 1130g of propylene oxide was slowly and continuously added to carry out polymerization reaction. After the polymerization reaction was completed, it was aged for 2h under positive pressure, and the residual monomers were removed by vacuum; and 250g of ethylene oxide was added at a slightly positive pressure and a temperature of 100°C for end-capping. Continue to add phosphoric acid for neutralization reaction, control the pH value between 6 and 7, the neutralization reaction temperature is 105°C, and stir for 2 hours; then add 7.5g of magnesium silicate adsorbent, the pH value is measured to be 8.8, control the temperature to 105°C, and stir for 1 hour; then add 90g of pure water, maintain the temperature at 105°C, and continue stirring for 2 hours; then heat to 110°C and decompress and dehydrate for 2 hours, then degas with nitrogen bubbling and medium-pressure steam bubbling for 2 hours, the medium-pressure steam pressure is 0.7Mpa, and the pressure in the kettle is -0.085Mpa; cool to ≤90°C and filter to obtain low-aldehyde, low-odor polyether.

[0044] (3) Preparation of polyurethane foam material:

[0045] Preparation of component A: 100 parts of the above polyether polyol, 1 part of diethanolamine, 2 parts of Dabco NE-1091, 1.5 parts of B-8734, and 3.5 parts of water were added to container A according to weight percentage, and stirred for 30 minutes to prepare component A. Preparation of component B: 32.5 parts of Desmodur 3133 were added to container B, and preheated to 50°C. Component A and component B were poured into the mold by a high-pressure foaming machine, or by a low-pressure foaming machine, and the mold temperature was set at 50°C. The mold was opened for 180 seconds and taken out from the mold to obtain a low-odor polyurethane foam material.

[0046] The performance test data of the prepared low-aldehyde, low-odor polyether polyol and polyurethane foam materials are shown in Tables 3-4.

[0047] Example 2

[0048] (1) Preparation of phosphazene catalyst:

[0049] In a 500ml three-necked flask equipped with a stirrer, a thermometer and a dropping funnel, 10g of phosphorus pentachloride and 110g of butyl ether solution were added. Under nitrogen protection, 55.3g of tetramethylguanidine was slowly added dropwise, and the reaction temperature was controlled at about 0°C. After the addition was completed, the temperature was slowly restored to room temperature, stirred at room temperature for 0.5h, and transferred to an oil bath, stirred at 110°C for 7h, cooled to room temperature and filtered to remove the precipitate, 6.6g of potassium acetate was added to the obtained solution, reacted at 80°C for 7h, cooled to room temperature and filtered, the filtrate was collected and the solvent was distilled off under reduced pressure, and the concentrate was recrystallized from methanol and n-hexane, wherein the volume ratio of methanol:n-hexane was 1:80, filtered and dried to obtain 20.4g of white powdery catalyst; the yield was 82%.

[0050] (2) Preparation of low-aldehyde, low-odor polyether polyols:

[0051] 120g of low molecular weight polyether 2 and 2.25g of the above-mentioned 0.15% phosphazene catalyst were added to a 2L autoclave, replaced with nitrogen three times, and degassed at 105°C and -0.09Mpa for 2h. At this time, the value of n in the general formula (II) is 0.014. At a pressure of -0.09Mpa and a temperature of 95°C in the autoclave, 1130g of propylene oxide was slowly and continuously added to carry out polymerization reaction. After the polymerization reaction was completed, it was aged for 2h under positive pressure, and the residual monomers were removed by vacuum; and 250g of ethylene oxide was added at a slightly positive pressure and a temperature of 100°C for end-capping. Continue to add phosphoric acid for neutralization reaction, control the pH value between 6 and 7, the neutralization reaction temperature is 105°C, and stir for 2 hours; then add 5.3g of magnesium silicate adsorbent, the pH value is measured to be 7.5, control the temperature to 105°C, and stir for 1 hour; then add 85g of pure water, maintain the temperature at 105°C, and continue stirring for 2 hours; then heat to 110°C and decompress and dehydrate for 2 hours, then degas with nitrogen bubbling and medium-pressure steam bubbling for 2 hours, the medium-pressure steam pressure is 0.7Mpa, and the pressure in the kettle is -0.085Mpa; cool to ≤90°C and filter to obtain low-aldehyde, low-odor polyether.

[0052] (3) Preparation of polyurethane foam material:

[0053] Preparation of component A: 100 parts of the above polyether polyol, 1 part of diethanolamine, 2 parts of Dabco NE-1091, 1.5 parts of B-8734, and 3.5 parts of water were added to container A according to weight percentage, and stirred for 30 minutes to prepare component A. Preparation of component B: 32.5 parts of Desmodur 3133 were added to container B, and preheated to 50°C. Component A and component B were poured into the mold by a high-pressure foaming machine, or by a low-pressure foaming machine, and the mold temperature was set at 50°C. The mold was opened for 180 seconds and taken out from the mold to obtain a low-odor polyurethane foam material.

[0054] The performance test data of the prepared low-aldehyde, low-odor polyether polyol and polyurethane foam materials are shown in Tables 3 to 5.

[0055] Example 3

[0056] (1) Preparation of phosphazene catalyst:

[0057] In a 500ml three-necked flask equipped with a stirrer, a thermometer and a dropping funnel, 10g of phosphorus pentachloride and a mixed solution of 45g of propionitrile and 45g of butyronitrile were added, and 46g of tetramethylguanidine was slowly added dropwise under nitrogen protection, and the reaction temperature was controlled at about 0°C. After the addition was completed, it was slowly restored to room temperature, stirred at room temperature for 0.5h, and transferred to an oil bath, stirred at 110°C for 3h, cooled to room temperature and filtered to remove the precipitate, 10.5g of potassium dihydrogen phosphate was added to the obtained solution, reacted at 70°C for 3h, cooled to room temperature and filtered, the filtrate was collected and the solvent was removed by distillation under reduced pressure, and the concentrate was slurried with n-butanol and n-heptane, wherein the volume ratio of n-butanol:n-heptane was 1:160, filtered and dried to obtain 21.6g of white powdery catalyst; the yield was 77%.

[0058] (2) Preparation of low-aldehyde, low-odor polyether polyols:

[0059] 120g of low molecular weight polyether 3 and 2.25g of the above-mentioned 0.15% phosphazene catalyst were added to a 2L autoclave, replaced with nitrogen three times, and degassed at 105°C and -0.09Mpa for 2h. At this time, the value of n in the general formula (II) is 0.021. At a pressure of -0.09Mpa and a temperature of 95°C in the autoclave, 1130g of propylene oxide was slowly and continuously added to carry out polymerization reaction. After the polymerization reaction was completed, it was aged for 2h under positive pressure, and the residual monomers were removed by vacuum; and 250g of ethylene oxide was added at a slightly positive pressure and a temperature of 100°C for end-capping. Continue to add phosphoric acid for neutralization reaction, control the pH value between 6 and 7, the neutralization reaction temperature is 105°C, and stir for 2 hours; then add 6.3g of magnesium silicate adsorbent, the pH value is measured to be 8.0, control the temperature to 105°C, and stir for 1 hour; then add 170g of pure water, maintain the temperature at 105°C, and continue stirring for 2 hours; then heat to 110°C and decompress and dehydrate for 2 hours, then degas with nitrogen bubbling and medium-pressure steam bubbling for 2 hours, the medium-pressure steam pressure is 0.7Mpa, and the pressure in the kettle is -0.085Mpa; cool to ≤90°C and filter to obtain low-aldehyde, low-odor polyether.

[0060] (3) Preparation of polyurethane foam material:

[0061] Preparation of component A: 100 parts of the above polyether polyol, 1 part of diethanolamine, 2 parts of Dabco NE-1091, 1.5 parts of B-8734, and 3.5 parts of water were added to container A according to weight percentage, and stirred for 30 minutes to prepare component A. Preparation of component B: 32.5 parts of Desmodur 3133 were added to container B, and preheated to 50°C. Component A and component B were poured into the mold by a high-pressure foaming machine, or by a low-pressure foaming machine, and the mold temperature was set at 50°C. The mold was opened for 180 seconds and taken out from the mold to obtain a low-odor polyurethane foam material.

[0062] The performance test data of the prepared low-aldehyde, low-odor polyether polyol and polyurethane foam materials are shown in Tables 3 to 5.

[0063] Embodiments 4 to 12

[0064] Examples 4 to 12 are carried out according to the steps of Examples 1 to 3. The specific formulas and related conditions are shown in Table 2. The performance test data of the prepared polyether polyol and polyurethane foam material are shown in Tables 3 to 4.

[0065] Comparative Examples 1 and 2 are polyether polyols prepared according to Examples 1 and 7 in Patent No. CN112876666A;

[0066] Comparative Example 3 is a polyether polyol prepared according to Example 1 in Patent No. CN116265508A.

[0067] Table 2 Specific formulations and related conditions of Examples 1 to 12

[0068]

[0069]

[0070]

[0071] Table 3 Data results of polyether polyols prepared in Examples 1 to 12 and Comparative Examples 1 to 3 (unit: ppm)

[0072]

[0073] Table 4 Data results of polyurethane foam materials prepared in Examples 1 to 12 and Comparative Examples 1 to 3 (unit: ppm)

[0074]

[0075]

[0076] Note: In the above table, the foam data was measured at 65℃ using the 10L bag method: the detection limit of benzene was 0.0010ppm, and the detection limit of aldehydes and ketones was 0.0017ppm. The data of polyether polyols was measured at 80℃ using the 10L bag method: the detection limit of benzene was 0.0010ppm, and the detection limit of aldehydes and ketones was 0.0017ppm.

[0077] The odor testing method of the polyether polyol of the present invention is as follows:

[0078] 100 ml of polyether polyol was placed in a 200 ml glass bottle and placed in an oven at room temperature of 25°C and 80°C for 2 hours. After being taken out, 8-10 people smelled the polyether polyol at intervals of 10 minutes and rated the odor according to the standards in the table below. The average of each person's rating was taken as the final result; the odor rating standard refers to VDA270, as shown in Table 5 below.

[0079] Table 5 Polyether polyol odor test standard (VDA270-2018)

[0080]

Claims

1. A low-aldehyde, low-odor polyether polyol, characterized in that: The polyether polyol is prepared by polymerization of active hydrogen compounds and olefin oxides using a phosphazene catalyst, and has a molecular weight of 800 to 15,000 and a functionality of 2 to 6. The formaldehyde content, acetaldehyde content, acrolein content, and propionaldehyde content of the polyether polyol are ≤0.01 ppm, ≤0.01 ppm, and odor level ≤3.

5. The general structural formula of the phosphazene catalyst is shown in the following formula (I): In the above general formula (I), X represents an alkali metal salt compound, - represents an alkali metal anion formed by the departure of the metal ion in X; wherein X is selected from one of sodium alkoxide, potassium alkoxide, sodium carboxylate, potassium carboxylate or metal phosphate; The continuous preparation method of the phosphazene catalyst comprises the following steps: (1) dissolving phosphorus pentahalide in an organic solvent to obtain a phosphorus pentahalide organic solution; slowly dropping a guanidine compound solution into the phosphorus pentahalide organic solution under an inert atmosphere at -15 to 5°C, returning the temperature to room temperature after the dropping is completed, stirring at room temperature, then heating in an oil bath, continuing the reaction, cooling to room temperature after the reaction is completed, filtering to remove precipitates, and obtaining an organic phosphonium salt solution containing the organic solvent and the halogenated phosphorus compound; (2) adding an alkali metal salt compound to the organic phosphonium salt solution obtained in step (1), reacting under an inert atmosphere and heating conditions, cooling and filtering after the reaction, and distilling the filtrate under reduced pressure to obtain a crude product of a phosphazene compound; The organic solvent is selected from at least one of nitriles or ethers; the alkali metal salt compound is selected from one of sodium alkoxide, potassium alkoxide, sodium carboxylate, potassium carboxylate or metal phosphate.

2. The low-aldehyde, low-odor polyether polyol according to claim 1, characterized in that: In the continuous preparation method of the phosphazene catalyst, in step (1), the mass ratio of phosphorus pentahalide to organic solvent is 1:6-12, the reaction temperature is controlled at 0-5°C under nitrogen protection; the molar ratio of phosphorus pentahalide to guanidine compound is 1:5-11; the temperature of oil bath heating is 80-120°C, and the stirring time is 3-8h.

3. The low-aldehyde, low-odor polyether polyol according to claim 1, characterized in that: In the continuous preparation method of the phosphazene catalyst, in step (2), the molar ratio of the organic phosphonium salt solution to the alkali metal salt compound is 1:1-2; the reaction time is 3-8h, and the reaction temperature is 50°C-80°C.

4. The low-aldehyde, low-odor polyether polyol according to claim 1, characterized in that: The organic solvent is selected from at least one of propionitrile, butyronitrile, adiponitrile, propyl ether, butyl ether or 1,4-dioxane; the alkali metal salt compound is selected from one of potassium methoxide, sodium methoxide, potassium ethoxide, sodium ethoxide, potassium formate, sodium formate, potassium acetate, sodium acetate, potassium dihydrogen phosphate or sodium dihydrogen phosphate.

5. The low-aldehyde, low-odor polyether polyol according to claim 1, characterized in that: The obtained crude phosphazene catalyst product is recrystallized or slurried for purification: The recrystallization step is as follows: recrystallizing the crude phosphazene catalyst product with a purification solvent, filtering, and drying to obtain a white powdery low-odor phosphazene catalyst; the purification solvent is selected from a mixed solution of at least one of nitriles or alcohols and at least one of ethers or alkanes; the volume ratio of at least one of nitriles or alcohols to at least one of ethers or alkanes is 1:2-300; The slurrying step is as follows: the crude phosphazene catalyst product is slurried with a purification solvent, filtered, and dried to obtain a white powdery low-odor phosphazene catalyst; the purification solvent is selected from a mixed solution of at least one of nitriles or alcohols and at least one of ethers or alkanes; the volume ratio of at least one of nitriles or alcohols to at least one of ethers or alkanes is 1:2-500.

6. A method for preparing the low-aldehyde, low-odor polyether polyol according to claim 1, characterized in that: The steps include: (1) using a low molecular weight polyether as an initiator, and preparing polyether polyol I by polymerization reaction in the presence of an olefin oxide and a phosphazene catalyst, controlling the reaction temperature to be 90 to 105° C., and the reaction pressure to be ≤0.45 MPa; the amount of the phosphazene catalyst added is 0.15 to 0.35% of the mass of the polyether polyol I; (2) Adding a neutralizing agent to the polyether polyol I for acid-base neutralization, stirring for a period of time, and then adding a magnesium silicate adsorbent, wherein the amount of the adsorbent added is 0.1 to 1% of the mass of the polyether polyol I; (3) Adding pure water to the polyether polyol I to be purified and continuing stirring for a period of time; the amount of pure water added is 3 to 15% of the mass of the polyether polyol I to be purified; (4) Heating and vacuum dehydration, and filter pressing to obtain low-aldehyde, low-odor polyether polyols.

7. The method for preparing low-aldehyde, low-odor polyether polyol according to claim 6, characterized in that: In the step (1), the phosphazene catalyst represented by the general formula (I) in claim 1 is mixed with an active hydrogen compound Y and subjected to a heating treatment to obtain a salt of a phosphazene cation represented by the general formula (II) and an anion of an active hydrogen compound; In the above general formula (II), n is a real number greater than 0 and less than or equal to 8, Y n- It represents the anion of the active hydrogen compound formed by the departure of n protons in the active hydrogen compound Y; Y is a polyether polyol having a functionality of 2 to 8 and a molecular weight of 300 to 2000.

8. The method for preparing low-aldehyde, low-odor polyether polyol according to claim 7, characterized in that: In the general formula (II), n is a real number greater than 0 and less than or equal to 1, and Y is a polyether polyol with a functionality of 2 to 6 and a molecular weight of 400 to 1200.

9. The method for preparing low-aldehyde, low-odor polyether polyol according to claim 6, characterized in that: The low molecular weight polyether in step (1) has a hydroxyl value of 200-300 mgKOH / g, a functionality of 2-6, and a molecular weight of 300-2000; the acid-base neutralization in step (2) controls the pH value of the material to 6-7, the material temperature to 90-120° C., and the material is stirred for 1-3 hours after adding the neutralizer; after adding the magnesium silicate adsorbent, the material temperature is controlled to 90-120° C., the pH value is 7-11, and the material is stirred for 1-3 hours.

10. Use of the low-aldehyde, low-odor polyether polyol according to claim 1 in the polyurethane industry which has high requirements on odor.

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