Preparation method of electronic-grade ammonium acetate

Abstract

The invention relates to the technical field of electronic chemicals, and particularly discloses a preparation method of electronic-grade ammonium acetate, which comprises the following steps: S1, uniformly mixing glacial acetic acid and acetone; s2, ammonia gas is added into the material obtained in the S1 for reaction, and slurry is obtained; and S3, carrying out solid-liquid separation on the slurry obtained in S2, and carrying out vacuum drying on the obtained solid phase to obtain ammonium acetate. When ammonium acetate is prepared, acetone is used as a dispersing agent, the hardening problem caused by direct reaction of ammonia gas and glacial acetic acid can be avoided, meanwhile, ammonium acetate generated by reaction of glacial acetic acid and ammonia gas is not dissolved in acetone, and rapid and effective separation of acetic acid and ammonium acetate can be achieved.

Description

Technical Field

[0001] The invention relates to the field of electronic chemicals, and in particular to a method for preparing electronic-grade ammonium acetate. Background Art

[0002] Ammonium acetate (CH3COONH4) is an important organic salt with various applications in the field of electronic chemicals. With the development of electronic products and semiconductor industries, ammonium acetate is widely used in wet etching, cleaning, polishing, solution preparation and other processes due to its buffering, solubility and strong complexing ability.

[0003] At present, electronic-grade ammonium acetate is mainly purified by repeated crystallization to achieve deep removal of various impurities, but the purification process is complicated and has strict requirements on each process link.

[0004] CN118930428A discloses a process for preparing electronic grade ammonium acetate, which uses industrial grade acetic acid as a raw material, reacts with excess ammonia water to generate a mixed solution of ammonium acetate and ammonia water, and the pH of the reaction solution is controlled to be 7-7.5 at the reaction end point; then the reaction is The mixed solution is concentrated under reduced pressure, cooled and crystallized, and after centrifugation, washing and drying, an electronic-grade ammonium acetate product with a content greater than 99% and a metal impurity content less than 5 ppb is obtained. This solution mainly achieves further purification of industrial-grade ammonium acetate through a crystallization process, which is usually time-consuming and energy-consuming. In addition, to obtain high-purity electronic-grade products, extremely high requirements are often placed on process control and equipment configuration during the crystallization process. Summary of the invention

[0005] The invention provides a method for preparing electronic-grade ammonium acetate. In the prepared ammonium acetate, the content of ammonium acetate is higher than 99.8%, and the content of total metal impurities is less than 100 ppt.

[0006] The technical solution of the present invention is to provide a method for preparing electronic grade ammonium acetate, comprising the following steps: S1. Mix glacial acetic acid and acetone evenly; S2, adding ammonia to the material obtained in S1 to react and obtain a slurry; The slurry obtained in S3 and S2 is subjected to solid-liquid separation, and the obtained solid phase is vacuum dried to obtain ammonium acetate.

[0007] Furthermore, the glacial acetic acid, acetone and ammonia are all electronic grade, and the purity is not lower than G3 level.

[0008] Furthermore, the volume ratio of glacial acetic acid to acetone in S1 is 1-3:1.

[0009] Furthermore, the volume ratio of glacial acetic acid to acetone in S1 is 2:1.

[0010] Furthermore, the molar ratio of the amount of ammonia added to glacial acetic acid in S2 is 1-2:1.

[0011] Furthermore, the molar ratio of the amount of ammonia added to glacial acetic acid in S2 is 1.5:1.

[0012] Furthermore, the reaction time in S2 is 2 to 4 hours.

[0013] Furthermore, the reaction time in S2 is 3 hours.

[0014] Furthermore, the drying temperature in S3 is 30-45° C., and the drying time is 2-6 hours.

[0015] Furthermore, the drying temperature in S3 is 35° C. and the drying time is 4 h.

[0016] The ratio of glacial acetic acid to acetone, and the ratio of ammonia to glacial acetic acid in the reaction solution are key factors that determine the quality of the prepared ammonium acetate. When the ratio of glacial acetic acid to acetone in the reaction solution is too high, when ammonia is passed into the reaction solution, glacial acetic acid and ammonia react rapidly to generate a large amount of ammonium acetate, causing the reaction solution to agglomerate or even harden, resulting in the reaction being unable to proceed smoothly. When the ratio of glacial acetic acid to acetone in the reaction solution is too low, the reaction yield and efficiency will be low. When the ratio of ammonia to glacial acetic acid in the reaction solution is low, that is, glacial acetic acid is excessive, at this time, some glacial acetic acid will be hidden in the ammonium acetate solid, affecting the quality of the ammonium acetate product. When the ratio of ammonia to glacial acetic acid in the reaction solution is high, the ammonia content in acetone will be too high. After centrifugation, the ammonia content in ammonium acetate is too high, which also affects the quality of the ammonium acetate product.

[0017] The present invention has the following beneficial effects: The solution provided by the present invention is to prepare electronic-grade ammonium acetate by one-step reaction crystallization using currently mass-produced electronic-grade raw materials. The entire process has simpler requirements on equipment, process control, etc. and is more conducive to implementation. In addition, when preparing ammonium acetate, acetone is used as a dispersant to avoid the "hardening" problem caused by the direct reaction of ammonia with glacial acetic acid. At the same time, the ammonium acetate generated by the reaction of glacial acetic acid with ammonia is insoluble in acetone, so that acetic acid and ammonium acetate can be quickly and effectively separated. DETAILED DESCRIPTION

[0018] The experimental methods in the following examples are conventional methods unless otherwise specified. The raw materials, reagents, etc. used in the following examples are commercially available products unless otherwise specified.

[0019] The present invention provides a method for preparing electronic grade ammonium acetate, comprising the following steps: S1. Evenly mix glacial acetic acid and acetone; the volume ratio of glacial acetic acid to acetone is 1-3:1, preferably 2:1.

[0020] S2, adding ammonia to the material obtained in S1 to react and obtain a slurry; the molar ratio of the added ammonia to the glacial acetic acid is 1-2:1, preferably 1.5:1. The reaction time is 2-4 hours, preferably 3 hours.

[0021] The slurry obtained in S3 and S2 is subjected to solid-liquid separation, and the obtained solid phase is vacuum dried to obtain ammonium acetate. The drying temperature is 30-45° C., and the drying time is 2-6 hours, preferably the drying temperature is 35° C., and the drying time is 4 hours.

[0022] The glacial acetic acid, acetone and ammonia used in the following examples and comparative examples are all electronic grade, and the purity is not less than G3 level. The present invention is described in detail below in conjunction with specific examples. This embodiment is implemented based on the technical solution of the present invention, and a detailed implementation method and specific operation process are given, but the protection scope of the present invention is not limited to the following examples.

[0023] Example 1 The preparation method of electronic grade ammonium acetate comprises the following main steps: 1) Preparation of reaction solution: Mix glacial acetic acid and acetone in a volume ratio of 2:1 to obtain a reaction solution.

[0024] 2) Reaction: Ammonia gas is introduced into the prepared reaction solution, with the molar ratio of ammonia gas to glacial acetic acid being 1.5:1, and the reaction is carried out for 2 hours to obtain a slurry.

[0025] 3) Solid-liquid separation: The obtained slurry is subjected to high-speed centrifugation to obtain solid crude ammonium acetate.

[0026] 4) Product drying: vacuum drying at 35°C for 4 hours to obtain electronic grade ammonium acetate product.

[0027] The electronic grade ammonium acetate content was tested using a near infrared spectrometer, and the metal ion content of the obtained ammonium acetate product was analyzed using ICP-MS. Detailed results are shown in Table 1.

[0028] Example 2 The preparation method of electronic grade ammonium acetate comprises the following main steps: 1) Preparation of reaction solution: Mix glacial acetic acid and acetone in a volume ratio of 1:1 to obtain a reaction solution.

[0029] 2) Reaction: Ammonia gas is introduced into the prepared reaction solution, with the molar ratio of ammonia gas to glacial acetic acid being 1:1, and the reaction is carried out for 1 hour to obtain a slurry.

[0030] 3) Solid-liquid separation: The obtained slurry is subjected to high-speed centrifugation to obtain solid crude ammonium acetate.

[0031] 4) Product drying: vacuum drying at 30°C for 6 hours to obtain electronic grade ammonium acetate product.

[0032] The electronic grade ammonium acetate content was tested using a near infrared spectrometer, and the metal ion content of the obtained ammonium acetate product was analyzed using ICP-MS. Detailed results are shown in Table 1.

[0033] Example 3 The preparation method of electronic grade ammonium acetate comprises the following main steps: 1) Preparation of reaction solution: Mix glacial acetic acid and acetone in a volume ratio of 3:1 to obtain a reaction solution.

[0034] 2) Reaction: Ammonia gas is introduced into the prepared reaction solution, with the molar ratio of ammonia gas to glacial acetic acid being 2:1, and the reaction is carried out for 3 hours to obtain a slurry.

[0035] 3) Solid-liquid separation: The obtained slurry is subjected to high-speed centrifugation to obtain solid crude ammonium acetate.

[0036] 4) Product drying: vacuum drying at 45°C for 2 hours to obtain electronic grade ammonium acetate product.

[0037] The electronic grade ammonium acetate content was tested using a near infrared spectrometer, and the metal ion content of the obtained ammonium acetate product was analyzed using ICP-MS. Detailed results are shown in Table 1.

[0038] Comparative Example 1 The preparation method of ammonium acetate comprises the following main steps: 1) Preparation of reaction solution: Mix glacial acetic acid and acetone in a volume ratio of 4:1 to obtain a reaction solution.

[0039] 2) Reaction: Ammonia gas is introduced into the prepared reaction solution, with the molar ratio of ammonia gas to glacial acetic acid being 1:1, and the reaction is carried out for 2 hours to obtain a slurry.

[0040] 3) Solid-liquid separation: The obtained slurry is subjected to high-speed centrifugation to obtain solid crude ammonium acetate.

[0041] 4) Product drying: vacuum drying at 30°C for 6 hours to obtain electronic grade ammonium acetate product.

[0042] The electronic grade ammonium acetate content was tested using a near infrared spectrometer, and the metal ion content of the obtained ammonium acetate product was analyzed using ICP-MS. Detailed results are shown in Table 1.

[0043] Comparative Example 2 The preparation method of ammonium acetate comprises the following main steps: 1) Preparation of reaction solution: Mix glacial acetic acid and acetone in a volume ratio of 1:1 to obtain a reaction solution.

[0044] 2) Reaction: Ammonia gas is introduced into the prepared reaction solution, with the molar ratio of ammonia gas to glacial acetic acid being 3:1, and the reaction is carried out for 2 hours to obtain a slurry.

[0045] 3) Solid-liquid separation: The obtained slurry is subjected to high-speed centrifugation to obtain solid crude ammonium acetate.

[0046] 4) Product drying: vacuum drying at 35°C for 2 hours to obtain electronic grade ammonium acetate product.

[0047] The electronic grade ammonium acetate content was tested using a near infrared spectrometer, and the metal ion content of the obtained ammonium acetate product was analyzed using ICP-MS. Detailed results are shown in Table 1.

[0048] Comparative Example 3 The preparation method of ammonium acetate comprises the following main steps: 1) Preparation of reaction solution: Mix glacial acetic acid and acetone in a volume ratio of 2:1 to obtain a reaction solution.

[0049] 2) Reaction: Ammonia gas is introduced into the prepared reaction solution, with the molar ratio of ammonia gas to glacial acetic acid being 1:1, and the reaction is carried out for 2 hours to obtain a slurry.

[0050] 3) Solid-liquid separation: The obtained slurry is subjected to high-speed centrifugation to obtain solid crude ammonium acetate.

[0051] 4) Product drying: vacuum drying at 45°C for 0.5 hour to obtain electronic grade ammonium acetate product.

[0052] The electronic grade ammonium acetate content was tested using a near infrared spectrometer, and the metal ion content of the obtained ammonium acetate product was analyzed using ICP-MS. Detailed results are shown in Table 1.

[0053] Comparative Example 4 The same as Example 1, except that acetone is not added. In fact, glacial acetic acid and ammonia react directly. The reaction speed is fast and difficult to control. In addition, when ammonia is introduced into the glacial acetic acid from the aeration head, the rapidly generated ammonium acetate at the aeration head will directly block the aeration head, resulting in the inability of ammonia to further enter the reaction solution.

[0054] The main difference between the process implemented in the above embodiment and the comparative example is that the ratio of glacial acetic acid to acetone in the reaction solution is different. Acetone, as a solvent for glacial acetic acid, dilutes the glacial acetic acid; too high a concentration of glacial acetic acid will cause the reaction process to be too fast, resulting in blockage of the aeration head or the generation of a large amount of ammonium acetate in a short time, causing hardening, affecting the diffusion of ammonia in the reaction solution, resulting in a large amount of unreacted acetic acid in the generated ammonium acetate, thereby affecting the purity of the final product of ammonium acetate; too low a concentration of glacial acetic acid leads to a low single crystal yield, which is uneconomical. In terms of other process conditions, if there is an excess of ammonia, the ammonium acetate product produced will be adsorbed with a large amount of ammonia. Although ammonia is effectively removed in the next drying process, the large amount of residual ammonia will cause low raw material utilization and poor economy on the one hand, and will also deteriorate the operating environment of the solid-liquid separation and product drying steps on the other hand. In the product drying process, the difference in drying temperature and drying time will lead to different residual amounts of acetone and ammonia in ammonium acetate, thereby affecting the quality of ammonium acetate finally obtained.

[0055] Table 1. Analysis and test results

[0056] It is not difficult to see from the results in Table 1 that the method provided by the present invention can achieve the preparation of electronic grade ammonium acetate, the ammonium acetate content is higher than 99.8%, and the metal ion impurities are less than 100 ppt.

[0057] The above embodiments describe the preferred implementation of the present invention, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing electronic grade ammonium acetate, characterized in that: The following steps are involved: S1. Mix glacial acetic acid and acetone evenly; S2, adding ammonia to the material obtained in S1 to react and obtain a slurry; The slurry obtained in S3 and S2 is subjected to solid-liquid separation, and the obtained solid phase is vacuum dried to obtain ammonium acetate.

2. The method according to claim 1, characterized in that: The glacial acetic acid, acetone and ammonia are all electronic grade, and the purity is not lower than G3 level.

3. The method according to claim 1, characterized in that: The volume ratio of glacial acetic acid to acetone in S1 is 1~3:

1.

4. The method according to claim 3, characterized in that: The volume ratio of glacial acetic acid to acetone in S1 is 2:

1.

5. The method according to claim 1, characterized in that: The molar ratio of the amount of ammonia added to glacial acetic acid in S2 is 1~2:

1.

6. The method according to claim 5, characterized in that: The molar ratio of the amount of ammonia added to glacial acetic acid in S2 is 1.5:

1.

7. The method according to any one of claims 1 to 6, characterized in that: The reaction time in S2 is 2 to 4 hours.

8. The method according to claim 7, characterized in that: The reaction time in S2 is 3 hours.

9. The method according to any one of claims 1 to 6, characterized in that: The drying temperature in S3 is 30~45°C, and the drying time is 2~6h.

10. The method according to claim 9, characterized in that: The drying temperature in S3 is 35°C and the drying time is 4 hours.

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