Low-odor phosphazene catalysts and their 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 a catalyst and its use, and particularly to a low-odor phosphazene catalyst and its use.

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 produce higher molecular weight and highly active polyether polyols with low unsaturation and few by-products. Some patents mention the manufacturing processes used to produce phosphazene catalysts, but these are complex, time-consuming, and inefficient. For example, in patents DE102006010034 and patent CN102171272B, multiple reaction and treatment steps are required to obtain the catalyst, and various raw materials, solvents, and water are involved in the process, consuming time and energy, and the waste water and waste may pollute the environment. In today's rapidly developing society, the waste of energy and environmental pollution are becoming increasingly serious. Due to this phenomenon, people need to pay attention to energy conservation and efficiency improvement during industrial production and always pay attention to the protection of the living environment.

[0003] Furthermore, while conventional technologies state that high molecular weight and low unsaturation polyether polyols can be produced using phosphazene catalytic processes, polyether polyols produced by phosphazene catalysts have a strong odor, making subsequent processing more complex. This odor originates from two main sources: one is the effect of the phosphazene catalyst, and the other is small molecular impurities such as by-products, 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 mainly use post-treatment methods such as neutralization and adsorption for processing crude polyethers. While these methods are optimized in terms of processes and raw materials, ultimately, the odor has not been significantly improved. With the continuous progress of society and people's relentless pursuit of better and healthier lives, customer requirements regarding the fragrance of polyether polyols and products manufactured therefrom are continuously increasing. Due to these factors, researchers are compelled to not only optimize the odor of polyether polyols, but also to optimize the catalyst powder to reduce the odor of the polyether and minimize the harmful substances produced by the polyether.

[0004] The prior art discloses a catalyst for the production of polyalkylene glycols. This catalyst is produced by manufacturing a phosphazenium salt intermediate in a benzene-based solvent using phosphorus pentachloride and tetramethylguanidine, purifying it, substituting the anion with hydroxide, mixing it with an active hydrogen compound, and heating it to obtain a catalyst for polyalkylene glycol production. This catalyst is used to further catalyze the polymerization of epoxy compounds such as propylene oxide and has been applied in the field of polyurethane foam materials. However, catalysts manufactured using toluene as a solvent have many problems, such as a strong odor and excess benzene-based substances. The prior art also discloses an organic alkoxide-based phosphazene catalyst produced by synthesizing an intermediate in a benzene-based solvent using phosphorus trichloride and tetramethylguanidine, and then performing ion exchange. The catalyst of this invention can catalyze the ring-opening polymerization of epoxy compounds to produce high molecular weight and low unsaturation polyether polyols.

[0005] As described above, conventional phosphazene catalyst production typically requires the use of several different organic solvents, including benzene-based substances. Therefore, after the reaction, the used organic solvents must be extracted and washed with water, and the reaction products must also be obtained by ion exchange. A large amount of wastewater and waste solvent is generated throughout the entire production process. Consequently, conventional phosphazene catalysts generally suffer from many problems in their production process, including high toxicity of raw materials and solvents, a large number of steps, complex operation, low economic efficiency, strong odor in the produced polyether product, strong odor in the produced polyurethane foam, and excessive amounts of benzene-based substances. [Overview of the project] [Problems that the invention aims to solve]

[0006] Objective of the Invention: The objective of the present invention is to provide a phosphazene catalyst that is easy to manufacture and has a low odor.

[0007] A second object of the present invention is to provide the use of the above-mentioned 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 continuous production method for the low-odor phosphazene catalyst is as follows: Step (1) involves dissolving phosphorus pentahalide in an organic solvent to obtain an organic phosphorus pentahalide solution, slowly adding a guanidine compound solution dropwise to the organic phosphorus pentahalide solution under an inert atmosphere and at -15 to 5°C, returning to room temperature after the addition is complete, stirring at room temperature, then heating in an oil bath to continue the reaction, cooling to room temperature after the reaction is complete, filtering to remove the precipitate, and obtaining an organic phosphonium salt solution containing the organic solvent and the phosphorus halide compound. Step (2) involves adding an alkali metal salt compound to the organic phosphonium salt solution obtained in step (1), reacting under inert atmosphere and heating conditions, cooling and filtering after the reaction is complete, and distilling the filtrate under reduced pressure to obtain a crude product of the 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 salt. [ka] (In the above general formula (I), X represents an alkali metal salt compound, and X - (where X represents an alkali metal anion formed by the detachment of a metal ion in X, where X is selected from sodium alkoxide, potassium alkoxide, sodium carboxylate, potassium carboxylate, sodium dihydrogen phosphate, or potassium dihydrogen phosphate.)

[0009] Furthermore, the organic solvent is at least one selected from propionitrile, butyronitrile, adiponitrile, propyl ether, butyl ether, or 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, or sodium dihydrogen phosphate.

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

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

[0012] In step (2) above, the molar ratio of the organic phosphonium salt solution to the alkali metal salt compound is 1:1 to 2, the reaction temperature is 50 to 80°C, the reaction time is 3 to 8 hours, and the reaction pressure is atmospheric 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 in 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 nitrile or alcohol and at least one ether or alkane, and the volume ratio of at least one nitrile or alcohol to at least one ether or alkane is 1:2 to 300, preferably 1:50 to 100. In the pulping step, the crude phosphazene catalyst is pulped 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 nitrile or alcohol and at least one ether or alkane, and the volume ratio of at least one nitrile or alcohol to at least one ether or alkane is 1:2 to 500, preferably 1:100 to 200.

[0015] Use of low-odor phosphazene catalysts in the production of the above-mentioned polyether polyols and polyurethane foams.

[0016] The low-odor phosphazene catalyst of general formula (I) and the 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, which is used in the production of polyether polyols. [ka] (In the above general formula (II), n is a real number greater than 0 and less than or equal to 8, and Y n- (This represents the anion of the active hydrogen compound formed by the detachment of n protons from the active hydrogen compound Y, where Y is a polyether polyol with 2 to 8 functional groups and a molecular weight of 300 to 2000.)

[0017] Furthermore, n is a real number greater than 0 and less than or equal to 1, and Y is a polyether polyol with 2 to 6 functional groups and a molecular weight of 400 to 1200. [Effects of the Invention]

[0018] Beneficial Effects: Compared to the prior art, the present invention achieves the following remarkable 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 to frequently exchange the solvent. By using the same solvent, steps such as extraction and distillation are omitted, reducing the energy consumption and the generation of wastewater and waste during the process. This continuous manufacturing method of the phosphazene catalyst can efficiently produce a phosphazene catalyst free of benzene-based substances and also plays a positive role in environmental protection. (2) The catalyst synthesized by this method can reduce the odor and increase the purity of this phosphazene catalyst by purification through pulping or recrystallization. The most important thing is that this manufacturing process provides strong support for the industrial production of the phosphazene catalyst. (3) The purified catalyst has a low impurity content and can significantly suppress small molecule impurities in the polyol produced subsequently. It can also significantly improve the odor of the polyurethane foam material produced. (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. Moreover, this catalyst maintains high catalytic activity when catalyzing polyether synthesis, not only reducing enterprise costs but also enhancing energy utilization efficiency and playing a positive role in energy conservation and emission reduction in society.

Embodiments for Carrying Out the Invention

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

[0020] The sources of related raw materials in various embodiments of the present invention are shown in Table 1 below.

[0021]

Table 1

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

[0023] (2) Production of polyether polyol: 120 g of CHE-307 polyether was added to a 2 L high-pressure reaction vessel, 3.0 g of the above phosphazene catalyst was added, the mixture 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 pressure inside the vessel reached -0.09 MPa and the temperature reached 95°C, 1130 g of propylene oxide was added dropwise to carry out the polymerization reaction. Nitrogen was introduced and the mixture was aged until the pressure inside the vessel became constant, and residual monomers were removed under vacuum negative pressure. At a slightly positive pressure and a temperature of 105°C, 250 g of ethylene oxide was added dropwise to cap the vessel, and nitrogen was introduced and the mixture was aged until the pressure inside the vessel became constant. Pure water and magnesium silicate adsorbent were added, the mixture was stirred at 105°C for 1 hour, then dehydrated under vacuum negative pressure and filtered to obtain the desired polyether polyol.

[0024] (3) Production of polyurethane foam: Preparation of component A: Add 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 to container A by weight percentage, and stir for 30 minutes to obtain component A. Preparation of component B: Add 32.5 parts of Desmodur 3133 to container B, and preheat both component A and component B to 50°C. Component A and component B were loaded into a mold using a high-pressure foaming machine, but they may also be loaded into a mold using a low-pressure foaming machine. Set the mold temperature to 50°C, and after 180 seconds, open the mold and remove the low-odor polyurethane foam. Tables 3-5 show the performance data detected for the manufactured phosphazene catalyst, polyether polyol, and polyurethane foam.

[0025] Example 2 (1) Production of phosphazene catalysts: Step 1: Add 10 g of phosphorus pentachloride and 90 g of propionitrile solution to a 500 ml three-necked flask equipped with a stirrer, thermometer, and dropping funnel. Slowly add 46 g of tetramethylguanidine dropwise under nitrogen protection, controlling the reaction temperature to approximately 0°C and the reaction pressure to atmospheric pressure. After the dropwise addition is complete, slowly return to room temperature, stir at room temperature for 0.5 hours, transfer to an oil bath, stir at 110°C for 3 hours, cool to room temperature, filter to remove precipitate, and obtain the solution. Step 2: Add 3.7 g of potassium methoxide to the solution obtained in Step 1 and react at 60°C and atmospheric pressure for 3 hours. After cooling to room temperature, filter the solution, collect the filtrate, and remove the solvent by vacuum distillation. Recrystallize the concentrate with acetonitrile and cyclohexane, where acetonitrile:cyclohexane (v / v) = 1:50. Filter and dry to obtain 19.4 g of purified phosphazene catalyst as a white powder (yield 78%). The general structural formula of the obtained phosphazene catalyst is shown by formula (I) above.

[0026] (2) Production of polyether polyol: 120 g of CHE-307 polyether was added to a 2 L high-pressure reaction vessel, 2.25 g of the above phosphazene catalyst was added, the mixture 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 pressure inside the vessel reached -0.09 MPa and the temperature reached 95°C, 1130 g of propylene oxide was added dropwise to carry out the polymerization reaction. Nitrogen was introduced and the mixture was aged until the pressure inside the vessel became constant, and residual monomers were removed under vacuum negative pressure. At a slightly positive pressure and a temperature of 105°C, 250 g of ethylene oxide was added dropwise to cap the mixture, and nitrogen was introduced and the mixture was aged until the pressure inside the vessel became constant. Pure water and magnesium silicate adsorbent were added, the mixture was stirred at 105°C for 1 hour, then dehydrated under vacuum negative pressure and filtered to obtain the desired polyether polyol.

[0027] (3) Production of polyurethane foam: Preparation of component A: Add 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 to container A by weight percentage, and stir for 30 minutes to obtain component A. Preparation of component B: Add 32.5 parts of Desmodur 3133 to container B, and preheat both component A and component B to 50°C. Component A and component B were loaded into a mold using a high-pressure foaming machine, but they may also be loaded into a mold using a low-pressure foaming machine. Set the mold temperature to 50°C, and after 180 seconds, open the mold and remove the low-odor polyurethane foam. Tables 3-5 show the performance data detected for the manufactured phosphazene catalyst, polyether polyol, and polyurethane foam.

[0028] Examples 3-12 In Examples 3 to 12, each step was carried out in the same manner as in Example 2, except that the formulation of the phosphazene catalyst differed. The specific formulations and related conditions are shown in Table 2. The performance data of the manufactured phosphazene catalyst, polyether polyol, and polyurethane foam are shown in Tables 3 to 5.

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

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

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

[0032] [Table 2] TIFF0007850866000005.tif241170TIFF0007850866000006.tif74170

[0033] [Table 3]

[0034] [Table 4] TIFF0007850866000009.tif79170

[0035] [Table 5] TIFF0007850866000011.tif90170

[0036] Note: In the table above, odor levels are measured according to the automotive industry's VDA270 standard. Foam data is measured at 65°C using the 10L bag method. The detection limit for benzene-based substances is 11.342 μg / m³. 3 The detection limit for aldehydes and ketones is 18.903 μg / m³. 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 / m³. 3 The detection limit for aldehydes and ketones is 19.742 μg / m³. 3 That is the case.

Claims

1. A continuous method for producing low-odor phosphazene catalysts, Step (1) involves dissolving phosphorus pentahalide in an organic solvent to obtain an organic phosphorus pentahalide solution, slowly adding a guanidine compound solution dropwise to the organic phosphorus pentahalide solution under an inert atmosphere and at -15 to 5°C, returning to room temperature after the addition is complete, stirring at room temperature, then heating in an oil bath to continue the reaction, cooling to room temperature after the reaction is complete, filtering to remove the precipitate, and obtaining an organic phosphonium salt solution containing the organic solvent and the phosphorus halide compound. Step (2) involves adding an alkali metal salt compound to the organic phosphonium salt solution obtained in step (1), reacting it under an inert atmosphere and heating conditions, cooling and filtering after the reaction is complete, and distilling the filtrate under reduced pressure to obtain a crude product of the 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 salt. The method for continuously producing a low-odor phosphazene catalyst is characterized in that the low-odor phosphazene catalyst comprises a phosphazene cation represented by general formula (I) and an alkali metal salt compound anion. 【Transformation 3】 (In the above general formula (I), X represents an alkali metal salt compound, X － (where X represents an alkali metal anion formed by the detachment of a metal ion in X, and X is selected from sodium alkoxide, potassium alkoxide, sodium carboxylate, potassium carboxylate, or metal phosphate salt.)

2. The method for continuously producing a low-odor phosphazene catalyst according to claim 1, characterized in that the organic solvent is at least one selected from propionitrile, butyronitrile, adiponitrile, propyl ether, butyl ether, or 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, or sodium dihydrogen phosphate.

3. The method for continuously producing a 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 to 12, the molar ratio of phosphorus pentahalide to guanidine compound is 1:5 to 11, the dropping temperature of the guanidine compound solution is 0 to 5°C, the oil bath heating temperature is 80 to 120°C, and the oil bath stirring reaction is carried out for 3 to 8 hours.

4. The method for continuously producing a 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 to 2, the reaction temperature is 50 to 80°C, and the reaction time is 3 to 8 hours.

5. The method for continuously producing a 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 recrystallized or pulped and purified. In the recrystallization step, the crude phosphazene catalyst is recrystallized in 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 nitrile or alcohol and at least one ether or alkane, and the volume ratio of at least one nitrile or alcohol to at least one ether or alkane is 1:2 to 300. The method for continuously producing a low-odor phosphazene catalyst according to claim 1, characterized in that, in the pulping step, the crude phosphazene catalyst is pulped 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, and the volume ratio of at least one of nitriles or alcohols to at least one of ethers or alkanes is 1:2 to 500.

7. Use of a low-odor phosphazene catalyst obtained by the continuous manufacturing method described in claim 1 in the production of a polyether polyol or polyurethane foam.

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

9. The use of a low-odor phosphazene catalyst in the production of a polyether polyol or polyurethane foam material according to claim 8, characterized in that n is a real number greater than 0 and less than or equal to 1, and Y is a polyether polyol having 2 to 6 functional groups.

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