Preparation method of aluminum capacitor electrolyte intermediate dialkyl phosphate diethylamine salt
By using alkyl imidazole acetic acid catalyst in the preparation of aluminum capacitor electrolyte intermediates, rapid reaction and simple purification are achieved, which solves the low efficiency and complexity problems of preparing dialkyl phosphate diethylamine salt in the existing technology, realizes the preparation of high-purity electrolyte, and improves the performance and production efficiency of aluminum capacitors.
Patent Information
- Application Number
- CN202510933227.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-07
- Publication Date
- 2025-10-10
AI Technical Summary
In the prior art, the method for preparing diethylamine dialkyl phosphate has a long reaction time, unsatisfactory conversion rate, complicated operation, and difficulty in large-scale industrial production. In addition, traditional electrolyte materials have problems such as low electrical conductivity and insufficient chemical stability.
Under a protective atmosphere, trialkyl phosphate, diethylamine and alkyl imidazole acetic acid are mixed and reacted, followed by purification. The alkyl imidazole acetic acid catalyst is used for rapid reaction at a relatively low temperature for 1.5-4 hours. The purification step is vacuum distillation and/or molecular distillation to prepare a high-purity dialkyl phosphate diethylamine salt.
The preparation of dialkyl phosphate diethylamine salt with high yield (over 90%) and high purity (greater than 99.5%) has been achieved, which improves the conductivity and cycle stability of aluminum capacitors, reduces costs, and is suitable for high-performance electronic devices.
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Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of fine chemicals, in particular to a method for preparing dialkyl phosphate diethylamine salt, an electrolyte intermediate of an aluminum capacitor. Background Art
[0002] Aluminum capacitors, as important electronic components, are widely used in various electronic devices. Their performance depends largely on the quality of their electrolyte intermediates. Traditional electrolyte intermediates for aluminum capacitors have several drawbacks, such as low purity, resulting in high leakage current and a short service life. Therefore, developing a method for preparing a high-purity dialkyl phosphate diethylamine salt electrolyte intermediate for aluminum capacitors is of great significance.
[0003] Aluminum capacitors, as key electronic components, play a vital role in electronic devices. Their applications are extensive, encompassing power filtering, signal coupling, energy storage, and more. With the rapid development of electronic technology, the performance requirements for aluminum capacitors are becoming increasingly stringent, especially for key indicators such as conductivity, stability, and service life, which directly determine the overall performance and reliability of electronic devices. As a core component of aluminum capacitors, the performance of the electrolyte has a decisive impact on their performance.
[0004] Currently, significant progress has been made in the research of aluminum capacitor electrolytes. Common electrolyte types include organic solvent electrolytes and solid-state electrolytes. Organic solvent electrolytes have good electrical conductivity and chemical stability, but they have some limitations. For example, they are easily volatilized at high temperatures, causing changes in the electrolyte concentration, which in turn affects the performance of the capacitor. In addition, organic solvent electrolytes have a high viscosity, which to some extent limits their use in certain specific applications. Solid-state electrolytes have high mechanical strength and good thermal stability, but their electrical conductivity is relatively low, and the preparation process is relatively complex and costly, which to some extent limits their large-scale application.
[0005] In recent years, with the deepening research on new electrolyte materials, dialkyl phosphate diethylamine salts have gradually attracted attention as a new electrolyte material. Dialkyl phosphate diethylamine salts have many excellent properties, such as high conductivity, good chemical stability, and compatibility with electrode materials. These characteristics give them broad application prospects in the field of aluminum capacitor electrolytes.
[0006] In the prior art, the method for preparing dialkyl phosphate diethylamine salt generally adopts a simple chemical reaction, in which dialkyl phosphate is mixed with diethylamine for reaction. However, this method has a long reaction time and an unsatisfactory conversion rate. It requires multiple purification and refining steps, which is not only complicated to operate but also has low production efficiency, making it difficult to achieve large-scale industrial production.
[0007] Therefore, developing a method for preparing high-purity dialkyl phosphate diethylamine salt is of great significance for improving production efficiency, enhancing the performance of aluminum capacitors, and meeting the needs of high-performance electronic equipment. Summary of the Invention
[0008] The present invention provides a method for preparing dialkyl phosphate diethylamine salt, an intermediate of an aluminum capacitor electrolyte, to at least solve one of the many defects in the prior art.
[0009] In view of this, the solution of the present invention is: The first aspect of the present invention is to propose a method for preparing dialkyl phosphate diethylamine salt, an electrolyte intermediate for aluminum capacitors. The steps include: mixing trialkyl phosphate, diethylamine and alkyl imidazole acetic acid under a protective atmosphere, fully reacting at 40-50°C, and then purifying to obtain dialkyl phosphate diethylamine salt.
[0010] The above preparation method has the following reaction process: .
[0011] Furthermore, the alkyl imidazole acetic acid is at least one selected from 1-ethyl-3-methyl imidazole acetic acid, 1-propyl-3-methyl imidazole acetic acid and 1-butyl-3-methyl imidazole acetic acid.
[0012] Furthermore, the molar ratio of the trialkyl phosphate, diethylamine and alkyl imidazole acetic acid is 1: (1.5-3.5): (1.5-3.5).
[0013] Preferably, the molar ratio of the trialkyl phosphate, diethylamine and alkyl imidazole acetic acid is 1:2:2.
[0014] Furthermore, the reaction time is 1.5-4h.
[0015] Preferably, the reaction temperature is 45° C. and the reaction time is 2 h.
[0016] Furthermore, the purification process is vacuum distillation and / or molecular distillation.
[0017] The second aspect of the present invention is to provide an aluminum capacitor electrolyte, which is 1,2,3,4-tetramethylimidazoline dialkyl phosphate salt; prepared from the intermediate dialkyl phosphate diethylamine salt; the preparation process of the intermediate dialkyl phosphate diethylamine salt includes the preparation method described in the first aspect.
[0018] Furthermore, the purity of the intermediate dialkyl phosphate diethylamine salt is greater than 99.5%.
[0019] Furthermore, the reaction process uses an alcohol solvent; and / or the reaction process is heated to 30° C. and reacts for 4-8 hours.
[0020] Preferably, the preparation method of the above-mentioned 1,2,3,4-tetramethylimidazoline dialkyl phosphate salt is specifically as follows: adding imidazoline carbonate monomethyl salt and ethanol to dialkyl phosphate diethylamine salt, then heating to 30°C, reacting for 4-8 hours, and then removing the low-boiling point solvent through post-treatment to obtain 1,2,3,4-tetramethylimidazoline dialkyl phosphate salt.
[0021] Compared with the prior art, the present invention has the following beneficial effects: The preparation method provided by the present invention uses an alkyl imidazole acetic acid catalyst, which can react rapidly at a relatively low temperature, with a reaction yield of over 90%. High-purity dialkyl phosphate diethylamine salt can be obtained by relying on a simple purification step, thereby significantly improving the performance stability of aluminum capacitors and reducing costs.
[0022] The preparation method described herein is simple, easy to operate, and low-cost, making it readily scalable for industrial production. The resulting high-purity dialkyl phosphate diethylamine salt electrolyte is light yellow, has a low color number, and exhibits excellent appearance. It exhibits excellent electrochemical properties and can effectively improve the conductivity and cycling stability of aluminum capacitors. It can be used to prepare tetramethylimidazoline dialkyl phosphate salt electrolytes, extending the service life of capacitors and meeting the requirements for aluminum capacitors in high-performance electronic devices, thus promising promising market applications. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 This is the H NMR spectrum of the product prepared in Example 4 of the present invention. DETAILED DESCRIPTION
[0024] The technical solutions of the present invention will be clearly and completely described below in conjunction with preferred embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.
[0025] In the following examples and comparative examples, high-purity dialkyl phosphate and diethylamine were selected as reaction raw materials, wherein the purity of the dialkyl phosphate was not less than 99.5%, and the purity of the diethylamine was not less than 99.0%.
[0026] Example 1
[0027] High-purity triethyl phosphate and diethylamine were mixed in a stoichiometric ratio of 1:3 at 45°C under a protective atmosphere. 1-ethyl-3-methylimidazole acetic acid, a catalyst, was added in the same proportion to triethyl phosphate and allowed to react for 3 hours. After completion of the reaction, vacuum distillation was performed to obtain a pale yellow, high-purity product with a purity of >99% and a yield of 85.3%.
[0028] Example 2
[0029] High-purity tripropyl phosphate and diethylamine were mixed in a stoichiometric ratio of 1:3.5 at 50°C under a protective atmosphere. 1-Ethyl-3-methylimidazole acetic acid (3-Methylimidazole Acetate) was added in the same proportion to tripropyl phosphate and allowed to react for 3 hours. After completion of the reaction, vacuum distillation was performed to obtain a pale yellow, high-purity product with a purity of >99% and a yield of 86.2%.
[0030] Example 3
[0031] High-purity tributyl phosphate and diethylamine were mixed in a stoichiometric ratio of 1:3 at 45°C under a protective atmosphere. 1-ethyl-3-methylimidazole acetic acid and dimethyl phosphate were added in the same proportion and allowed to react for 3.5 hours. After completion of the reaction, vacuum distillation was performed to obtain a pale yellow, high-purity product with a purity of >99% and a yield of 90.5%.
[0032] Example 4
[0033] Under a protective atmosphere at 45°C, high-purity triethyl phosphate and diethylamine were added in a stoichiometric ratio of 1:2, and the catalyst 1-ethyl-3-methylimidazole acetic acid was added in the same ratio to triethyl phosphate to react for 2 hours. After the reaction was completed, vacuum distillation was performed to obtain a light yellow high-purity product with a purity of >99% and a yield of 96.5%. Figure 1 As shown, the H NMR spectrum data is: 1 H-NMR (400MHz,CDCl3) ≈ 10.13 ppm(2H), ≈ 3.96 - 3.88 ppm (5H), ≈ 2.59 ppm (4H), ≈ 1.59 (6H), ≈ 1.24 ppm (6H).
[0034] Comparative Example 1
[0035] High-purity triethyl phosphate and diethylamine were mixed in a stoichiometric ratio of 1:2 at 45°C under a protective atmosphere. Without adding a catalyst, the mixture was reacted for 2 hours and then subjected to reduced pressure distillation to obtain a light yellow product with a yield of 35.5%.
[0036] Comparative Example 2
[0037] High purity triethyl phosphate and diethylamine were mixed in stoichiometric ratio 1:3 under 45 °C protective atmosphere, without adding catalyst, after 8 hours of reaction, vacuum distillation was first carried out to obtain light yellow product, the yield was 43.6%.
[0038] Comparative Example 3
[0039] High purity trimethyl phosphate and diethylamine were mixed in stoichiometric ratio 1:5 under 45 °C protective atmosphere, 1-ethyl-3-methylimidazole acetate catalyst of the same proportion of trimethyl phosphate was added, and the reaction was carried out for 2 hours. After the reaction was completed, vacuum distillation was first carried out, and then separation and purification were carried out to obtain light yellow high purity product, the yield was 80.1%.
[0040] Preparation Example 1
[0041] The steps for preparing 1, 2, 3, 4-tetramethyl imidazoline dialkyl phosphate salt electrolyte with the dialkyl phosphate diethylamine salt prepared in Example 4 as an intermediate raw material include: adding imidazoline monomethyl carbonate salt and ethanol to the dialkyl phosphate diethylamine salt, then heating to 40 °C, and reacting for 6 hours, then removing low boiling point solvents by post-treatment to obtain 1, 2, 3, 4-tetramethyl imidazoline dialkyl phosphate salt electrolyte.
[0042] Preparation Example 2
[0043] The steps for preparing 1, 2, 3, 4-tetramethyl imidazoline dialkyl phosphate salt electrolyte with the dialkyl phosphate diethylamine salt prepared in Example 4 as an intermediate raw material include: adding imidazoline monomethyl carbonate salt and ethanol to the dialkyl phosphate diethylamine salt, then heating to 40 °C, and reacting for 8 hours, then removing low boiling point solvents by post-treatment to obtain 1, 2, 3, 4-tetramethyl imidazoline dialkyl phosphate salt electrolyte.
[0044] Test Example
[0045] The 1, 2, 3, 4-tetramethyl imidazoline dialkyl phosphate salt obtained in the above preparation example was used as a solute to prepare an electrolyte with a GBL content of 20%. The appearance and electrolyte performance were evaluated, and the results were as follows: the color number was low, the conductivity was greater than 12000 us / cm, the flash voltage was greater than 120v, and the service life of the 105 °C simulation capacitor could reach 14500 hours.
[0046] Although embodiments of the present application have been shown and described, it is to be understood that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A method for preparing dialkyl phosphate diethylamine salt, an intermediate of an aluminum capacitor electrolyte, characterized in that the steps include: Under a protective atmosphere, trialkyl phosphate, diethylamine and alkyl imidazole acetic acid are mixed, fully reacted at 40-50° C., and then purified to obtain dialkyl phosphate diethylamine salt.
2. The preparation method according to claim 1, characterized in that The alkyl imidazole acetic acid is selected from at least one of 1-ethyl-3-methyl imidazole acetic acid, 1-propyl-3-methyl imidazole acetic acid and 1-butyl-3-methyl imidazole acetic acid.
3. The preparation method according to claim 1, characterized in that The molar ratio of the trialkyl phosphate, diethylamine and alkyl imidazole acetic acid is 1: (1.5-3.5): (1.5-3.5).
4. The preparation method according to claim 2, characterized in that The molar ratio of the trialkyl phosphate, diethylamine and alkyl imidazole acetic acid is 1:3:
3.
5. The preparation method according to claim 1, characterized in that The reaction time is 1.5-4h.
6. The preparation method according to claim 1 or 4, characterized in that The reaction temperature is 45° C. and the reaction time is 2 h.
7. The preparation method according to claim 1, characterized in that The purification process is vacuum distillation and / or molecular distillation.
8. Aluminum capacitor electrolyte, comprising 1, 2, 3, 4-tetramethylimidazoline dialkyl phosphate salt; characterized in that: It is prepared from an intermediate dialkyl phosphate diethylamine salt and imidazoline carbonate monomethyl salt; the preparation process of the intermediate dialkyl phosphate diethylamine salt includes the preparation method according to claim 1.
9. The aluminum electrolysis container electrolyte according to claim 8, characterized in that The purity of the intermediate dialkyl phosphate diethylamine salt is greater than 99.5%.
10. The aluminum capacitor electrolyte according to claim 8, characterized in that The reaction process uses an alcohol solvent; and / or the reaction process is heated to 30° C. and reacts for 4-8 hours.