Low odor phosphazene catalyst and its use

Abstract

The present invention discloses a low-odor phosphazene catalyst and its use. The catalyst comprises a phosphazene cation represented by the general formula (I) and an alkali metal salt compound anion. The catalyst is prepared by dissolving a phosphorus pentahalide and a guanidine compound in a non-benzene-based organic solvent and reacting them under heated conditions to obtain an organic phosphonium salt solution containing the organic solvent and the phosphorus halide compound. An alkali metal salt compound is then added and reacted under heated conditions in an inert atmosphere to obtain a purified phosphazene catalyst through filtration, reduced-pressure distillation, purification, and vacuum drying. The catalyst can be used in the production of polyether polyols and polyurethane foams. The phosphazene catalyst of the present invention employs a non-benzene-based inert solvent that does not participate in the reaction during production, eliminating the need for frequent solvent changes. Using the same solvent eliminates steps such as extraction and distillation, reducing energy consumption and wastewater generation during the process. The continuous production method for the phosphazene catalyst is efficient and environmentally friendly.

Description

[Technical Field]

[0001] The present invention relates to catalysts and uses thereof, and in particular to low odor phosphazene catalysts and uses thereof. [Background technology]

[0002] Phosphazene catalysts have excellent ring-opening catalytic ability, high activity and stability in the reaction process, and few side-reaction products, allowing the production of higher molecular weight, more active polyether polyols with low unsaturation and fewer by-products. Several patents describe manufacturing processes used to produce phosphazene catalysts, but these are complex, time-consuming, and inefficient. For example, Patent DE102006010034 and Patent CN102171272B require multiple reaction and processing steps to obtain the catalyst, which involve various raw materials, solvents, and water, resulting in time and energy consumption and the generation of wastewater and waste products that can pollute the environment. In today's rapidly developing society, energy waste and environmental pollution are becoming increasingly serious. This phenomenon necessitates people to pay attention to energy conservation and efficiency in industrial production and to constantly protect the living environment.

[0003] Furthermore, while the prior art describes the production of high-molecular-weight, low-unsaturation polyether polyols using phosphazene-catalyzed processes, these polyether polyols have a strong odor and require more complicated processing. The odor is primarily caused by two factors: the phosphazene catalyst itself and small molecular impurities, such as by-products and alcohols, aldehydes, ketones, and benzenes, generated during the reaction. These impurities often affect the properties of polyurethane materials produced from polyether polyols. Currently, polyether manufacturers in China and abroad primarily use post-treatment methods such as neutralization and adsorption to process crude polyether. While these methods have been optimized in terms of process and raw materials, the odor remains largely unresolved. With the ongoing progress of society and the relentless pursuit of a better and healthier life for everyone, customer requirements for the fragrance of polyether polyols and the products made from them are continually increasing. These factors have forced researchers to not only optimize the odor of polyether polyols, but also to optimize catalyst powders to reduce the odor of polyethers and reduce the harmful substances caused by polyethers.

[0004] Prior art discloses catalysts for the production of polyalkylene glycols. This catalyst is prepared by preparing a phosphazenium salt intermediate in a benzene-based solvent using phosphorus pentachloride and tetramethylguanidine. After purification, the anion is replaced with a hydroxide, and the intermediate is mixed with an active hydrogen compound and heated to obtain a catalyst for the production of polyalkylene glycols. This catalyst is then used to further catalyze the polymerization of epoxy compounds such as propylene oxide, and is applied in the field of polyurethane foams. However, catalysts prepared using toluene as a solvent during production suffer from numerous problems, including a strong odor and excessive benzene-based substances. Prior art also discloses organic alcoholate-based phosphazene catalysts prepared by synthesizing an intermediate in a benzene-based solvent using phosphorus trichloride and tetramethylguanidine, followed by ion exchange. This catalyst can catalyze the ring-opening polymerization of epoxy compounds to produce high-molecular-weight, low-unsaturation polyether polyols.

[0005] As described above, the production of phosphazene catalysts in the prior art usually requires the use of several different organic solvents, including benzene-based substances. Therefore, after the reaction, the organic solvent used must be extracted and washed with water, and the reaction product must be obtained by ion exchange. The entire production process generates a large amount of wastewater and waste solvent. Therefore, in the prior art, phosphazene catalysts generally have many problems in the production process, such as high toxicity of raw materials and solvents, many steps, complicated operation, low economic efficiency, strong odor of the produced polyether products, strong odor of the produced polyurethane foams, and excessive benzene-based substances. Summary of the Invention [Problem to be solved by the invention]

[0006] OBJECT OF THE INVENTION: The object of the present invention is to provide a phosphazene catalyst which has a simple manufacturing process and low odor.

[0007] A second object of the present invention provides the use of the above low odor phosphazene catalyst in the production of polyether polyols and polyurethane foams. [Means for solving the problem]

[0008] Technical solution: The low odor phosphazene catalyst of the present invention comprises a phosphazene cation represented by general formula (I) and an alkali metal salt compound anion, The method for continuously producing a low odor phosphazene catalyst comprises: Step (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 a temperature of -15 to 5°C; after the addition is complete, the temperature is returned to normal, the mixture is stirred at room temperature, and then heated in an oil bath to continue the reaction; after the reaction is complete, the mixture is cooled to room temperature and filtered to remove the precipitate, thereby obtaining an organic phosphonium salt solution containing the organic solvent and the phosphorus halide compound; and step (2) adding an alkali metal salt compound to the organic phosphonium salt solution obtained in step (1), reacting them under an inert atmosphere and heating conditions, and after the reaction is completed, cooling and filtering the mixture, and distilling the filtrate under reduced pressure to obtain a crude phosphazene compound. The organic solvent is at least one selected from nitriles or ethers, and the alkali metal salt compound is one selected from sodium alkoxide, potassium alkoxide, sodium carboxylate, potassium carboxylate, or metal phosphate. [ka] (In the above general formula (I), X represents an alkali metal salt compound, and X - represents an alkali metal anion formed by the elimination of the metal ion in X, where X is one selected from sodium alkoxide, potassium alkoxide, sodium carboxylate, potassium carboxylate, sodium dihydrogen phosphate, and potassium dihydrogen phosphate.

[0009] Furthermore, the organic solvent is at least one selected from propionitrile, butyronitrile, adiponitrile, propyl ether, butyl ether, and 1,4-dioxane, and the alkali metal salt compound is one selected from potassium methoxide, sodium methoxide, potassium ethoxide, sodium ethoxide, potassium formate, sodium formate, potassium acetate, sodium acetate, potassium dihydrogen phosphate, and sodium dihydrogen phosphate.

[0010] In the step (1), the phosphorus pentahalide is one selected from phosphorus pentabromide and phosphorus pentachloride, and the guanidine compound is 1,1,3,3-tetramethylguanidine.

[0011] In the step (1), the mass ratio of the phosphorus pentahalide to the organic solvent is 1:6-12, the molar ratio of the phosphorus pentahalide to the guanidine compound is 1:5-11, the temperature is 0-5°C, the oil bath heating temperature is 80-120°C, and the oil bath stirring reaction is carried out for 3-8 hours.

[0012] 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 3-8 hours, and the reaction pressure is normal pressure.

[0013] The crude phosphazene compound obtained in step (2) is purified by recrystallization or pulping.

[0014] Furthermore, in the recrystallization step, the crude phosphazene catalyst is recrystallized with a purification solvent, filtered and dried to obtain a white powdery low-odor phosphazene catalyst, wherein 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, and the volume ratio of the at least one of the nitriles or alcohols to the at least one of the ethers or alkanes is 1:2-300, preferably 1:50-100; In the pulping step, the phosphazene catalyst crude product is pulped with a purification solvent, filtered and dried to obtain a white powdery low-odor phosphazene catalyst, wherein 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, and the volume ratio of the at least one of the nitriles or alcohols to the at least one of the ethers or alkanes is 1:2-500, preferably 1:100-200.

[0015] Use of a low odor phosphazene catalyst in the production of the above polyether polyols and polyurethane foams.

[0016] The low odor phosphazene catalyst of the general formula (I) and the active hydrogen compound Y are mixed and heated to obtain a salt of the phosphazene cation and the active hydrogen compound anion represented by the general formula (II), which is used in the production of polyether polyol. [ka] (In the above general formula (II), n is a real number greater than 0 and equal to or less than 8, and Y n- represents an anion of an active hydrogen compound formed by the elimination of n protons from an active hydrogen compound Y, and Y is a polyether polyol having 2 to 8 functional groups and a molecular weight of 300 to 2000.

[0017] Furthermore, n is a real number greater than 0 and equal to or less than 1, and Y is a polyether polyol having 2 to 6 functional groups and a molecular weight of 400 to 1,200. [Effects of the Invention]

[0018] Beneficial Effects: Compared with the prior art, the present invention achieves the following significant effects: (1) The phosphazene catalyst of the present invention employs a non-benzene-based inert solvent that does not participate in the reaction during production, eliminating the need for frequent solvent changes. Using the same solvent eliminates steps such as extraction and distillation, reducing energy consumption and wastewater generation during the process. This continuous production method for phosphazene catalysts enables efficient production of benzene-free phosphazene catalysts, thereby contributing to environmental protection. (2) The catalyst synthesized by this method can be purified by pulping or recrystallization to reduce the odor and increase the purity of the phosphazene catalyst. Most importantly, this production process provides strong support for the industrial production of phosphazene catalysts. (3) The purified catalyst has a low impurity content, significantly reducing small molecule impurities in the resulting polyol and significantly improving the odor of the resulting polyurethane foam. (4) When the value of n in 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 high catalytic activity when catalyzing polyether synthesis, which not only reduces corporate costs but also improves energy utilization efficiency and plays an active role in energy conservation and emission reduction in society. DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention will be described in more detail below.

[0020] The sources of relevant ingredients in various embodiments of the present invention are listed in Table 1 below.

[0021] [Table 1]

[0022] Example 1 (1) Preparation of phosphazene catalyst: Step 1: In a 500ml three-necked flask equipped with a stirrer, thermometer, and dropping funnel, add 10g of phosphorus pentachloride and 90g of propionitrile solution. Under nitrogen protection, slowly add 46g of tetramethylguanidine dropwise. Control the reaction temperature to about 0℃ and the reaction pressure to normal pressure. After the addition is complete, slowly return to normal temperature and stir at normal temperature for 0.5 hours. Transfer to an oil bath and stir at 110℃ for 3 hours. Cool to room temperature, then filter to remove precipitate and obtain a solution. Step 2: 3.7 g of potassium methoxide was added to the solution obtained in Step 1, and the mixture was reacted at 60°C and atmospheric pressure for 3 hours. After cooling to room temperature, the mixture was filtered, and the filtrate was collected and distilled under reduced pressure to obtain 23.6 g of unpurified phosphazene catalyst as a dark oil (yield 94.8%).

[0023] (2) Preparation of polyether polyol: 120 g of CHE-307 polyether was added to a 2 L high-pressure reactor, and 3.0 g of the above phosphazene catalyst was added. The reactor was purged with nitrogen three times and degassed at 105°C and -0.09 MPa for 2 hours. At this time, the n value in general formula (II) was 0.025. When the reactor pressure reached -0.09 MPa and the temperature reached 95°C, 1130 g of propylene oxide was added dropwise to initiate the polymerization reaction. Nitrogen was introduced and the reactor was aged until the reactor pressure became constant, and then the residual monomer was removed under negative vacuum. At a slight positive pressure and a temperature of 105°C, 250 g of ethylene oxide was added dropwise and capped, and nitrogen was introduced and the reactor was aged until the reactor pressure became constant. Pure water and magnesium silicate adsorbent were added, and the mixture was stirred at 105°C for 1 hour. The mixture was then dehydrated under negative vacuum and filtered to obtain the desired polyether polyol.

[0024] (3) Production of Polyurethane Foam: Preparation of Component A: 100 parts by weight of the above polyether polyol, 1 part by weight of diethanolamine, 2 parts by weight of Dabco NE-1091, 1.5 parts by weight of B-8734, and 3.5 parts by weight of water were added to Container A and stirred for 30 minutes to obtain Component A. Preparation of Component B: 32.5 parts by weight of Desmodur 3133 were added to Container B, and both Component A and Component B were preheated to 50°C. Components A and B were charged into a mold using a high-pressure foaming machine, but they may also be charged into a mold using a low-pressure foaming machine. The mold temperature was set to 50°C, and after 180 seconds, the mold was opened and the low-odor polyurethane foam was removed. Tables 3 to 5 show data on the performance of the produced phosphazene catalyst, polyether polyol, and polyurethane foam material.

[0025] Example 2 (1) Preparation of phosphazene catalyst: Step 1: In a 500ml three-necked flask equipped with a stirrer, thermometer, and dropping funnel, add 10g of phosphorus pentachloride and 90g of propionitrile solution. Under nitrogen protection, slowly add 46g of tetramethylguanidine dropwise. Control the reaction temperature to about 0℃ and the reaction pressure to normal pressure. After the addition is complete, slowly return to normal temperature and stir at normal temperature for 0.5 hours. Transfer to an oil bath and stir at 110℃ for 3 hours. Cool to room temperature, then filter to remove precipitate and obtain a solution. Step 2: 3.7 g of potassium methoxide was added to the solution obtained in Step 1 and reacted at 60°C and atmospheric pressure for 3 hours. After cooling to room temperature, the mixture was filtered. The filtrate was collected and the solvent was removed by distillation under reduced pressure. The concentrated solution was recrystallized from acetonitrile and cyclohexane, where the acetonitrile:cyclohexane (v / v) ratio was 1:50. After filtration and drying, 19.4 g of purified phosphazene catalyst was obtained as a white powder (78% yield). The general structural formula of the obtained phosphazene catalyst is shown in Formula (I) above.

[0026] (2) Preparation of polyether polyol: 120 g of CHE-307 polyether was added to a 2 L high-pressure reactor, and 2.25 g of the above phosphazene catalyst was added. The reactor was purged with nitrogen three times and degassed at 105°C and -0.09 MPa for 2 hours. At this time, the n value in general formula (II) was 0.025. When the reactor pressure reached -0.09 MPa and the temperature reached 95°C, 1130 g of propylene oxide was added dropwise to initiate the polymerization reaction. Nitrogen was introduced and the reactor was aged until the reactor pressure became constant, and then the residual monomer was removed under negative vacuum. At a slight positive pressure and a temperature of 105°C, 250 g of ethylene oxide was added dropwise and capped, and nitrogen was introduced and the reactor was aged until the reactor pressure became constant. Pure water and magnesium silicate adsorbent were added, and the mixture was stirred at 105°C for 1 hour. The mixture was then dehydrated under negative vacuum and filtered to obtain the desired polyether polyol.

[0027] (3) Production of Polyurethane Foam: Preparation of Component A: 100 parts by weight of the above polyether polyol, 1 part by weight of diethanolamine, 2 parts by weight of Dabco NE-1091, 1.5 parts by weight of B-8734, and 3.5 parts by weight of water were added to Container A and stirred for 30 minutes to obtain Component A. Preparation of Component B: 32.5 parts by weight of Desmodur 3133 were added to Container B, and both Component A and Component B were preheated to 50°C. Components A and B were charged into a mold using a high-pressure foaming machine, but they can also be charged into a mold using a low-pressure foaming machine. The mold temperature was set to 50°C, and after 180 seconds, the mold was opened and the low-odor polyurethane foam was removed. Tables 3 to 5 show data on the performance of the produced phosphazene catalyst, polyether polyol, and polyurethane foam material.

[0028] Examples 3 to 12 In Examples 3 to 12, each step was the same as in Example 2, except that the relevant formulations of the phosphazene catalyst were different. The specific formulations and relevant conditions are shown in Table 2. The performance data of the prepared phosphazene catalyst, polyether polyol, and polyurethane foam material are shown in Tables 3 to 5.

[0029] Comparative Example 1 In Comparative Example 1, a phosphazene catalyst was prepared according to Example 1 of Patent No. CN104497046B using toluene as a solvent.

[0030] Comparative Example 2 In Comparative Example 2, a phosphazene catalyst was prepared using toluene according to Synthesis Example 1 of Patent CN102171272B.

[0031] Comparative Example 3 In Comparative Example 3, a phosphazene catalyst was prepared using toluene according to the methods of Examples 1, 2, and 5 of Patent No. DE102006010034. When the related phosphazene catalysts obtained in Comparative Examples 1 to 3 are used to prepare polyether polyols and polyurethane foams, the steps are the same as in Examples 1 to 12, and the performance data of the prepared phosphazene catalysts, polyether polyols, and polyurethane foams are shown in Tables 3 to 5.

[0032] [Table 2] TIFF2025533408000006.tif241170TIFF2025533408000007.tif74170

[0033] [Table 3]

[0034] [Table 4] TIFF2025533408000010.tif79170

[0035] [Table 5] TIFF2025533408000012.tif90170

[0036] Note: In the table above, odor levels are measured according to the automotive industry standard VDA270. Foam data is measured at 65°C using the 10L bag method. The detection limit for benzene-based substances is 11.342 μg / m 3 The detection limit for aldehydes and ketones is 18.903 μg / m 3 The data for raw materials such as catalysts and polyether polyols were measured at 80°C using the 10L bag method, and the detection limit for benzene-based substances was 11.845 μg / m 3 The detection limit for aldehydes and ketones is 19.742 μg / m 3 is.

Claims

1. 1. A low odor phosphazene catalyst comprising: The phosphazene cation represented by the general formula (I) and the alkali metal salt compound anion are included, The method for continuously producing a low odor phosphazene catalyst comprises: Step (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 a temperature of −15 to 5° C.; after the addition is complete, the solution is returned to room temperature, stirred at room temperature, and then heated in an oil bath to continue the reaction; after the reaction is complete, the solution is cooled to room temperature and filtered to remove the precipitate, thereby obtaining an organic phosphonium salt solution containing the organic solvent and the phosphorus halide compound; and step (2) adding an alkali metal salt compound to the organic phosphonium salt solution obtained in step (1), reacting them under an inert atmosphere and heating conditions, and after the reaction is completed, cooling and filtering the mixture, and distilling the filtrate under reduced pressure to obtain a crude phosphazene compound. The organic solvent is at least one selected from nitriles or ethers, and the alkali metal salt compound is one selected from sodium alkoxide, potassium alkoxide, sodium carboxylate, potassium carboxylate, or metal phosphate. 【Chemistry 3】 (In the above general formula (I), X represents an alkali metal salt compound, and X － represents an alkali metal anion formed by the detachment of a metal ion in X, and X is one selected from sodium alkoxide, potassium alkoxide, sodium carboxylate, potassium carboxylate, and metal phosphate.

2. 2. The low-odor phosphazene catalyst according to claim 1, wherein the organic solvent is at least one selected from propionitrile, butyronitrile, adiponitrile, propyl ether, butyl ether, and 1,4-dioxane, and the alkali metal salt compound is one selected from potassium methoxide, sodium methoxide, potassium ethoxide, sodium ethoxide, potassium formate, sodium formate, potassium acetate, sodium acetate, potassium dihydrogen phosphate, and sodium dihydrogen phosphate.

3. The low-odor phosphazene catalyst according to claim 1, characterized in that in 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 stirring reaction is carried out for 3-8 hours.

4. The low odor phosphazene catalyst according to claim 1, characterized in that in 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 one selected from phosphorus pentabromide or phosphorus pentachloride, and the guanidine compound is 1,1,3,3-tetramethylguanidine.

6. The crude phosphazene compound obtained in step (2) is purified by recrystallization or pulping; In the recrystallization step, the crude phosphazene catalyst is recrystallized with a purification solvent, filtered and dried to obtain a white powdery low-odor phosphazene catalyst, wherein the purification solvent is selected from a mixture of at least one of nitriles or alcohols and at least one of ethers or alkanes, and the volume ratio of the at least one of the nitriles or alcohols to the at least one of the ethers or alkanes is 1:2-300; The low-odor phosphazene catalyst according to claim 1, characterized in that in the pulping step, the phosphazene catalyst crude product is pulped with a purification solvent, filtered and dried to obtain a white powdery low-odor phosphazene catalyst, wherein 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, and the volume ratio of the at least one of the nitriles or alcohols to the at least one of the ethers or alkanes is 1:2-500.

7. 10. Use of the low odor phosphazene catalyst of claim 1 in the production of polyether polyols and polyurethane foams.

8. 8. Use of the low-odor phosphazene catalyst in the production of polyether polyol and polyurethane foam material according to claim 7, characterized in that the phosphazene catalyst represented by general formula (I) and an active hydrogen compound Y are mixed and heated to obtain a salt of the phosphazene cation represented by general formula (II) and the active hydrogen compound anion. 【Chemistry 4】 (In the above general formula (II), n is a real number greater than 0 and equal to or less than 8, and Y ｎ－ represents an anion of an active hydrogen compound formed by the elimination of n protons from an active hydrogen compound Y, and Y is a polyether polyol having 2 to 8 functional groups and a molecular weight of 300 to 2000.

9. 9. The use of a low-odor phosphazene catalyst in producing a polyether polyol and a polyurethane foam material according to claim 8, wherein n is a real number greater than 0 and equal to or less than 1, and Y is a polyether polyol having a functionality of 2 to 6 and a molecular weight of 400 to 1,200.

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