Low-odor phosphazene catalyst and use thereof

Abstract

A low-odor phosphazene catalyst and use thereof. The catalyst comprises phosphazene cations and anions as shown in general formula (I). In the catalyst, phosphorus pentahalide and a guanidine compound are used as raw materials, the phosphorous pentahalide is dissolved in a non-benzene organic solution, a reaction is then performed under heating conditions to obtain an organic phosphonium salt solution containing an organic solvent and a halogenated phosphorus compound, then an alkali metal salt compound is added, a reaction is then performed under an inert atmosphere and heating conditions, followed by filtering, reduced pressure distillation, purification, and vacuum drying to obtain a purified phosphazene catalyst. The catalyst is used for preparing polyether polyol and polyurethane foam materials. Preparation of the phosphazene catalyst makes use of a non-benzene, non-reacting inert solvent. The solvent does not require frequent replacement; that is, steps such as extraction and distillation are reduced by using the same solvent, thereby reducing energy consumption and the generation of waste water and waste material. The continuous-type preparation method for the phosphazene catalyst is efficient and environmentally friendly.

Description

A low-odor phosphazene catalyst and its application Technical Field

[0001] The present invention relates to a catalyst and application thereof, in particular to a low-odor phosphazene catalyst and application thereof. Background Art

[0002] Phosphazene catalysts have excellent ring-opening catalytic ability, high activity and stability in the reaction process, few side reaction products, and can prepare polyether polyols with higher molecular weight and higher activity, and low unsaturation and few by-products. Some patents mention the preparation process used when preparing phosphazene catalysts. Its process technology is complicated, time-consuming and inefficient. For example, patent DE102006010034 and patent CN102171272B require multi-step reaction and multi-step treatment to obtain the catalyst. The process involves multiple raw materials, solvents and water, and there is a phenomenon of serious time-consuming and energy-consuming wastewater and waste materials polluting the environment. In today's rapidly developing society, energy waste and environmental pollution are becoming increasingly serious. This phenomenon forces people to pay attention to energy saving and efficiency improvement when carrying out industrial production, and it is more necessary to pay attention to the protection of the living environment.

[0003] In addition, the prior art mentions that the use of phosphazene catalyst processes can prepare high molecular weight, low unsaturation polyether polyols. However, polyether polyols produced using phosphazene catalyst systems have a strong odor, which makes subsequent processing more complicated. The odor mainly comes from two parts: one is the influence of the selection of phosphazene catalysts, and the other is the byproducts produced during the reaction and some small molecular impurities such as alcohols, aldehydes, ketones and benzenes. These impurities often affect the performance of the polyurethane material prepared from the polyether polyol. At present, the treatment methods used by polyether manufacturers at home and abroad for crude polyether are mostly post-treatment methods such as neutralization and adsorption. These are all optimized from the process and raw materials, but the odor is not much improved. With the continuous progress of society and people's constant pursuit of a better and healthier life, the customer group's demand for the odor of polyether polyols and products prepared therefrom is constantly increasing. These factors force researchers to not only optimize the odor of polyether polyols, but also optimize the catalyst end to reduce the odor of polyethers and reduce the harmful substances brought by polyethers.

[0004] The prior art discloses a catalyst for producing polyalkylene glycols. This catalyst uses phosphorus pentachloride and tetramethylguanidine in a benzene solvent to prepare a phosphazenium salt intermediate. After purification, the anion is replaced with hydroxide, and the catalyst is then mixed with an active hydrogen compound and heated to obtain a catalyst for producing polyalkylene glycols. This catalyst is then used to further catalyze the polymerization of epoxides such as propylene oxide, and is used in the field of polyurethane foams. However, the catalyst produced using toluene as a solvent in production suffers from numerous problems, such as a strong odor and excessive levels of benzene. The prior art also discloses an organic alkoxide phosphazene catalyst prepared by synthesizing an intermediate using phosphorus trichloride and tetramethylguanidine in a benzene solvent, followed by ion exchange. This catalyst can also be used in the ring-opening polymerization of epoxides to produce high-molecular-weight, low-unsaturation polyether polyols.

[0005] In summary, the preparation of phosphazene catalysts in the prior art typically requires the use of several different organic solvents containing benzene series. After the reaction, the organic solvents used must be extracted and washed with water, and the reaction product must also undergo ion exchange. This generates a large amount of wastewater and waste solvents throughout the entire preparation process. Consequently, phosphazene catalysts in the prior art generally suffer from numerous problems, including high toxicity hazards associated with the raw materials or solvents used in the manufacturing process, the need for numerous steps, complex operations, low economic efficiency, and a strong odor in the resulting polyether product, a strong odor in the resulting polyurethane foam, and excessive levels of benzene series.

[0006] Summary of the Invention

[0007] Purpose of the invention: The purpose of the present invention is to provide a low-odor phosphazene catalyst with a simple preparation process and low odor;

[0008] The second object of the present invention is to provide the use of the low-odor phosphazene catalyst in polyether polyols and polyurethane foam materials.

[0009] Technical solution: The low-odor phosphazene catalyst of the present invention comprises a phosphazene cation represented by the general formula (I) and an alkali metal salt compound anion;

[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, sodium dihydrogen phosphate or potassium dihydrogen phosphate;

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

[0012] (1) dissolving phosphorus pentahalide in an organic solvent to obtain a phosphorus pentahalide organic solution; slowly adding a guanidine compound solution dropwise to the phosphorus pentahalide organic solution under an inert atmosphere at -15 to 5°C; after the addition is completed, returning the temperature to room temperature and stirring at room temperature; then heating in an oil bath to continue the reaction; after the reaction is completed, cooling the mixture to room temperature, filtering, and removing the precipitate to obtain 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 after the reaction is completed, filtering, and distilling the filtrate under reduced pressure to obtain a crude product of the 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] Furthermore, the organic solvent is selected from at least one of propionitrile, butyronitrile, adiponitrile, propyl ether, butyl ether or 1,4-dioxane; and 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.

[0016] Wherein, in the step (1), the phosphorus pentahalide is selected from phosphorus pentabromide or phosphorus pentachloride; and the guanidine compound is 1,1,3,3-tetramethylguanidine.

[0017] Wherein, in the step (1), the mass ratio of phosphorus pentahalide to organic solvent is 1:6-12; the molar ratio of phosphorus pentahalide to guanidine compound is 1:5-11; the temperature is 0-5°C; the temperature of the oil bath heating is 80-120°C, and the oil bath stirring reaction is carried out for 3-8 hours.

[0018] Wherein, in the step (2), the molar ratio of the organic phosphonium salt solution to the alkali metal salt compound is 1:1-2; the reaction temperature is 50-80°C, the reaction time is 3-8h, and the reaction pressure is normal pressure.

[0019] The crude phosphazene compound product obtained in step (2) is recrystallized or slurried for purification.

[0020] Furthermore, 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 the at least one of nitriles or alcohols to the at least one of ethers or alkanes is 1:2 to 300, preferably 1:50 to 100;

[0021] The beating step is as follows: beating 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 the at least one of nitriles or alcohols to the at least one of ethers or alkanes is 1:2 to 500, preferably 1:100 to 200.

[0022] Application of the low-odor phosphazene catalyst in the preparation of polyether polyols and polyurethane foam materials.

[0023] The low-odor phosphazene catalyst of general formula (I) is mixed with an active hydrogen compound Y and subjected to heat treatment to obtain a salt of a phosphazene cation and an active hydrogen compound anion represented by general formula (II), which is used to prepare polyether polyols.

[0024] 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.

[0025] Furthermore, n is a real number greater than 0 and less than or equal to 1, and Y is a polyether polyol having a functionality of 2 to 6 and a molecular weight of 400 to 1200.

[0026] Beneficial effects: Compared with the prior art, the present invention achieves the following significant effects:

[0027] (1) The phosphazene catalyst of the present invention uses only one non-benzene 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 materials in the process. Through the continuous preparation method of the phosphazene catalyst, a phosphazene catalyst without benzene series can be efficiently prepared, which also plays a positive role in environmental protection. (2) The catalyst synthesized in this way is then purified by pulping or recrystallization, which can make the phosphazene catalyst have lower odor and higher purity. Most importantly, this preparation process provides strong support for the industrial production of phosphazene catalysts. (3) The impurity content of the purified catalyst is low, which can significantly inhibit the small molecular impurities in the polyol prepared subsequently. At the same time, the odor of the prepared polyurethane foam can also be significantly improved. (4) 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, and the catalyst maintains a high catalytic activity when catalyzing the synthesis of polyethers, which can not only reduce corporate costs, but also enhance energy utilization efficiency, and play a positive role in social energy conservation and emission reduction. DETAILED DESCRIPTION

[0028] The present invention is described in further detail below.

[0029] The sources of relevant raw materials in various embodiments of the present invention are shown in Table 1 below.

[0030] Table 1 List of raw materials

[0031] [Example 1]

[0032] (1) Preparation of phosphazene catalyst:

[0033] Step 1: Add 10g of phosphorus pentachloride and 90g of propionitrile solution to a 500ml three-necked flask equipped with a stirrer, a thermometer, and a dropping funnel. Under nitrogen protection, slowly add 46g of tetramethylguanidine dropwise. Control the reaction temperature at about 0°C and the reaction pressure at normal pressure. After the addition is completed, slowly return to room temperature, stir at room temperature for 0.5h, transfer to an oil bath, stir at 110°C for 3h, cool to room temperature, and filter to remove the precipitate to obtain a solution;

[0034] Step 2: Add 3.7 g of potassium methoxide to the solution obtained in step 1, react at 60°C and normal pressure for 3 h, cool to room temperature, filter, collect the filtrate and distill under reduced pressure to obtain 23.6 g of unpurified dark oily phosphazene catalyst with a yield of 94.8%.

[0035] (2) Preparation of polyether polyols: 120 g of CHE-307 polyether was added to a 2 L autoclave, along with 3.0 g of the phosphazene catalyst mentioned above. The reaction mixture was nitrogen-purged three times and degassed at 105°C and -0.09 MPa for 2 h. At this time, the value of n in the general formula (II) was 0.025. 1130 g of propylene oxide was added dropwise at a pressure of -0.09 MPa and a temperature of 95°C to initiate polymerization. The reaction mixture was aging with nitrogen until the pressure in the autoclave remained constant, and residual monomers were removed under vacuum. 250 g of ethylene oxide was added dropwise at a slightly positive pressure and a temperature of 105°C to terminate the reaction mixture, and the reaction mixture was aging with nitrogen until the pressure in the autoclave remained constant. Pure water and magnesium silicate adsorbent were added, and the reaction mixture was stirred at 105°C for 1 h, followed by vacuum dehydration and filtration to obtain the desired polyether polyol.

[0036] (3) Preparation of polyurethane foam material: Preparation of component A: Add 100 parts of the above-mentioned polyether polyol, 1 part of diethanolamine, 2 parts of Dabco NE-1091, 1.5 parts of B-8734, and 3.5 parts of water to container A according to weight percentage, and stir for 30 minutes to prepare component A. Preparation of component B: Add 32.5 parts of Desmodur 3133 to container B, and preheat both materials A and B to 50°C. Pour components A and B into a mold using a high-pressure foaming machine, or a low-pressure foaming machine; set the mold temperature at 50°C, open the mold after 180 seconds, and remove from the mold to obtain a low-odor polyurethane foam material.

[0037] The performance test data of the prepared phosphazene catalyst, polyether polyol and polyurethane foam material are shown in Tables 3 to 5.

[0038] [Example 2]

[0039] (1) Preparation of phosphazene catalyst:

[0040] Step 1: Add 10g of phosphorus pentachloride and 90g of propionitrile solution to a 500ml three-necked flask equipped with a stirrer, a thermometer, and a dropping funnel. Under nitrogen protection, slowly add 46g of tetramethylguanidine dropwise. Control the reaction temperature at about 0°C and the reaction pressure at normal pressure. After the addition is completed, slowly return to room temperature, stir at room temperature for 0.5h, transfer to an oil bath, stir at 110°C for 3h, cool to room temperature, and filter to remove the precipitate to obtain a solution;

[0041] Step 2: 3.7 g of potassium methoxide was added to the solution obtained in step 1. The mixture was reacted at 60°C and atmospheric pressure for 3 h. After cooling to room temperature, the mixture was filtered. The filtrate was collected and the solvent was removed by distillation under reduced pressure. The concentrate was recrystallized from acetonitrile and cyclohexane (acetonitrile:cyclohexane (v / v) = 1:50). The mixture was filtered and dried to obtain 19.4 g of a purified white powdered phosphazene catalyst in a yield of 78%. The general structural formula of the obtained phosphazene catalyst is shown in formula (I) above.

[0042] (2) Preparation of polyether polyols: 120 g of CHE-307 polyether and 2.25 g of the above-mentioned phosphazene catalyst were added to a 2 L autoclave, and the atmosphere was replaced with nitrogen three times. The mixture was degassed at 105°C and -0.09 MPa for 2 h. At this time, the value of n in the general formula (II) was 0.025. When the pressure in the autoclave was -0.09 MPa and the temperature was 95°C, 1130 g of propylene oxide was added dropwise to carry out polymerization. The mixture was filled with nitrogen and aged until the pressure in the autoclave remained constant. Residual monomers were removed under vacuum. 250 g of ethylene oxide was added dropwise at a slightly positive pressure and a temperature of 105°C for end-capping. The mixture was filled with nitrogen and aged until the pressure in the autoclave remained constant. Pure water and magnesium silicate adsorbent were added, and the mixture was stirred at 105°C for 1 h, then dehydrated under vacuum and filtered to obtain the desired polyether polyol.

[0043] (3) Preparation of polyurethane foam material: Component A was prepared by adding 100 parts of the above-mentioned polyether polyol, 1 part of diethanolamine, 2 parts of Dabco NE-1091, 1.5 parts of B-8734, and 3.5 parts of water to container A according to weight percentage, and stirring for 30 minutes to prepare component A. Component B was prepared by adding 32.5 parts of Desmodur 3133 to container B, and preheating both materials A and B to 50°C. Components A and B were poured into a mold using a high-pressure foaming machine, or a low-pressure foaming machine. The mold temperature was set at 50°C, and the mold was opened after 180 seconds to obtain a low-odor polyurethane foam material.

[0044] The performance test data of the prepared phosphazene catalyst, polyether polyol and polyurethane foam material are shown in Tables 3 to 5.

[0045] [Examples 3 to 12]

[0046] Examples 3 to 12 were carried out according to the steps of Example 2, except that the relevant formula of the phosphazene catalyst was different. The specific formula and relevant conditions are shown in Table 2. The performance test data of the prepared phosphazene catalyst, polyether polyol and polyurethane foam material are shown in Tables 3 to 5.

[0047] [Comparative Example 1]

[0048] Comparative Example 1 is a phosphazene catalyst prepared according to Example 1 of Patent No. CN104497046B, wherein the solvent is toluene.

[0049] [Comparative Example 2]

[0050] Comparative Example 2 is to prepare the phosphazene catalyst using toluene according to Synthesis Example 1 of Patent CN102171272B;

[0051] [Comparative Example 3]

[0052] Comparative Example 3 is a method for preparing a phosphazene catalyst using toluene according to Examples 1, 2, and 5 of Patent No. DE102006010034.

[0053] The preparation steps of the relevant phosphazene catalysts obtained in Comparative Examples 1 to 3 for polyether polyols and polyurethane foam materials are consistent with those in Examples 1 to 12. The performance test data of the phosphazene catalysts, polyether polyols and polyurethane foam materials are shown in Tables 3 to 5.

[0054] Table 2 Specific formulas and related conditions of Examples 1 to 12

[0055] Table 3 Data results of phosphazene catalysts of Examples 1 to 12 and Comparative Examples 1 to 3 (unit: μg / m3 )

[0056] Table 4 Data results of polyether polyols prepared with catalysts of Examples 1 to 12 and Comparative Examples 1 to 3 (unit: μg / m 3 )

[0057] Table 5 Data results of polyurethane foam materials prepared from polyols of Examples 1 to 12 and Comparative Examples 1 to 3 (unit: μg / m 3 )

[0058] Note: The odor levels in the above table are measured according to the automotive industry VDA270 standard. Foam data was measured at 65°C using a 10L bag method: the detection limit for benzene series is 11.342ug / m 3 The detection limit of aldehydes and ketones was 18.903ug / m 3 The data of raw materials such as catalysts and polyether polyols were measured at 80°C using a 10L bag method: the detection limit of benzene series was 11.845ug / m 3 The detection limit of aldehydes and ketones was 19.742ug / m 3 .

Claims

1. A low-odor phosphazene catalyst, characterized in that: Comprising a phosphazene cation represented by the general formula (I) and an alkali metal salt compound anion; 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 low-odor 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, removing 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-odor phosphazene catalyst 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.

3. The low-odor phosphazene catalyst according to claim 1, characterized in that In the step (1), the mass ratio of phosphorus pentahalide to organic solvent is 1:6-12; the molar ratio of phosphorus pentahalide to guanidine compound is 1:5-11; the temperature is 0-5°C; the temperature of oil bath heating is 80-120°C, and the oil bath is stirred for reaction for 3-8h.

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

5. The low-odor phosphazene catalyst according to claim 1, characterized in that In step (1), the phosphorus pentahalide is selected from phosphorus pentabromide or phosphorus pentachloride; and the guanidine compound is 1,1,3,3-tetramethylguanidine.

6. The low-odor phosphazene catalyst according to claim 1, characterized in that Recrystallize or slurry the crude phosphazene compound obtained in step (2) 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.

7. Use of the low-odor phosphazene catalyst according to claim 1 in the preparation of polyether polyols and polyurethane foam materials.

8. Use of the low-odor phosphazene catalyst according to claim 7 in the preparation of polyether polyols and polyurethane foam materials, characterized in that: The phosphazene catalyst represented by the general formula (I) is mixed with the active hydrogen compound Y and subjected to a heat treatment to obtain a salt of the phosphazene cation represented by the general formula (II) and the active hydrogen compound anion. 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.

9. Use of the low-odor phosphazene catalyst according to claim 8 in the preparation of polyether polyols and polyurethane foam materials, characterized in that: The 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.

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