Process for the preparation of electronic grade ammonium acetate

Abstract

The application 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, adding ammonia gas into the material obtained in S1 to carry out a reaction, so as to obtain a slurry; and S3, carrying out solid-liquid separation on the slurry obtained in S2, vacuum-drying the obtained solid phase, and obtaining the ammonium acetate. In the preparation of the ammonium acetate, the acetone is used as a dispersing agent, so that the "hardening" problem caused by the direct reaction between the ammonia gas and the glacial acetic acid can be avoided, and the ammonium acetate generated by the reaction between the glacial acetic acid and the ammonia gas is insoluble in the acetone, so that the glacial acetic acid and the ammonium acetate can be rapidly and effectively separated.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electronic chemicals, in particular to a preparation method of electronic-grade ammonium acetate. BACKGROUND

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

[0003] Currently, electronic-grade ammonium acetate is mainly purified by repeated crystallization to achieve deep removal of various impurities, but the purification process is complex and requires strict control of each process step.

[0004] CN118930428A discloses a preparation process of electronic-grade ammonium acetate, which uses industrial-grade acetic acid as raw material to react with excess ammonia water to generate a mixed solution of ammonium acetate and ammonia water. The reaction endpoint is controlled to have a reaction liquid pH of 7-7.5. Then the reaction

[0005] The mixed solution is concentrated under reduced pressure, cooled and crystallized, centrifuged, washed, and dried to obtain electronic-grade ammonium acetate with a content of more than 99% and a metal impurity content of less than 5 ppb. This scheme mainly realizes the further purification of industrial-grade ammonium acetate through the crystallization process, but the crystallization process usually has the problems of time-consuming and energy-consuming, and to obtain high-purity electronic-grade products, the process control and equipment configuration during crystallization often have very high requirements. SUMMARY

[0006] The present application provides a preparation method of electronic-grade ammonium acetate, which has an ammonium acetate content of more than 99.8% and a total metal impurity content of less than 100 ppt.

[0007] The technical solution of the present application is to provide a preparation method of electronic-grade ammonium acetate, which comprises the following steps:

[0008] S1, uniformly mixing glacial acetic acid and acetone;

[0009] S2, adding ammonia gas to the material obtained in S1 to obtain a slurry;

[0010] S3, performing solid-liquid separation on the slurry obtained in S2, and vacuum drying the obtained solid phase to obtain ammonium acetate.

[0011] Further, the glacial acetic acid, acetone, and ammonia gas are all electronic-grade and have a purity of not less than G3 level.

[0012] Further, the volume ratio of glacial acetic acid to acetone in S1 is 1-3:1.

[0013] Further, the volume ratio of the glacial acetic acid and the acetone in S1 is 2:1.

[0014] Further, the molar ratio of the ammonia gas and the glacial acetic acid in S2 is 1~2:1.

[0015] Further, the molar ratio of the ammonia gas and the glacial acetic acid in S2 is 1.5:1.

[0016] Further, the reaction time in S2 is 2~4 hours.

[0017] Further, the reaction time in S2 is 3 hours.

[0018] Further, the drying temperature in S3 is 30~45℃, and the drying time is 2~6h.

[0019] Further, the drying temperature in S3 is 35℃, and the drying time is 4h.

[0020] The ratio of the glacial acetic acid and the acetone, and the ratio of the ammonia gas and the glacial acetic acid in the reaction liquid are key factors for determining the quality of the prepared ammonium acetate. When the ratio of the glacial acetic acid and the acetone in the reaction liquid is too high, the glacial acetic acid and the ammonia gas react rapidly to generate a large amount of ammonium acetate when the ammonia gas is introduced into the reaction liquid, which causes the reaction liquid to be blocked or even hardened, and thus the reaction cannot be carried out smoothly. When the ratio of the glacial acetic acid and the acetone in the reaction liquid is too low, the reaction yield and efficiency are low. When the ratio of the ammonia gas and the glacial acetic acid in the reaction liquid is too low, that is, the glacial acetic acid is excessive, part of the glacial acetic acid is hidden in the ammonium acetate solid, which affects the quality of the ammonium acetate product. When the ratio of the ammonia gas and the glacial acetic acid in the reaction liquid is too high, the ammonia gas content in the acetone is too high, and after centrifugal separation, the ammonia content in the ammonium acetate is too high, which also affects the quality of the ammonium acetate product.

[0021] The present application has the following beneficial effects:

[0022] The scheme provided by the present application realizes the preparation of electronic-grade ammonium acetate through one-step reaction crystallization by using the currently mass-produced electronic-grade raw materials, and the whole process has simpler requirements for equipment and process control and is easier to implement. In addition, when preparing ammonium acetate, the use of acetone as a dispersing agent can avoid the problem of "hardening" caused by the direct reaction of ammonia gas with glacial acetic acid, and the ammonium acetate generated by the reaction of glacial acetic acid and ammonia gas is insoluble in acetone, which can realize the rapid and effective separation of acetic acid and ammonium acetate. DETAILED DESCRIPTION

[0023] In the following examples, the experimental methods are conventional methods unless otherwise specified. In the following examples, the raw materials, reagents and materials used are commercially available products unless otherwise specified.

[0024] The application provides a preparation method of electronic-grade ammonium acetate, which comprises the following steps:

[0025] S1, uniformly mixing glacial acetic acid and acetone; the volume ratio of glacial acetic acid to acetone is 1-3:1, preferably 2:1.

[0026] S2, adding ammonia gas to the material obtained in S1 to perform reaction to obtain slurry; the molar ratio of the amount of ammonia gas to glacial acetic acid is 1-2:1; preferably 1.5:1. The reaction time is 2-4 hours, preferably 3 hours.

[0027] S3, performing solid-liquid separation on the slurry obtained in S2 to obtain solid phase, and performing vacuum drying on the solid phase to obtain ammonium acetate. The drying temperature is 30-45℃, and the drying time is 2-6 hours; preferably, the drying temperature is 35℃, and the drying time is 4 hours.

[0028] The glacial acetic acid, acetone and ammonia gas used in the following examples and comparative examples are all electronic-grade, and the purity is not less than G3 level. The application will be described in detail below in combination with specific examples. The examples are implemented on the premise of the technical scheme of the application, and detailed implementation modes and specific operation processes are given, but the protection scope of the application is not limited to the following examples.

[0029] Example 1

[0030] The preparation method of electronic-grade ammonium acetate comprises the following main steps:

[0031] 1) Preparation of reaction liquid: uniformly mixing glacial acetic acid and acetone at a volume ratio of 2:1 to obtain a reaction liquid.

[0032] 2) Reaction: introducing ammonia gas into the prepared reaction liquid, the molar ratio of ammonia gas to glacial acetic acid is 1.5:1, and the reaction is performed for 2 hours to obtain slurry.

[0033] 3) Solid-liquid separation: performing high-speed centrifugation on the obtained slurry to obtain solid ammonium acetate crude product.

[0034] 4) Product drying: vacuum drying at 35℃ for 4 hours to obtain electronic-grade ammonium acetate product.

[0035] The content of electronic-grade ammonium acetate is tested by using a near-infrared spectrometer, and the metal ion content of the obtained ammonium acetate product is analyzed by using ICP-MS. The detailed results are shown in Table 1.

[0036] Example 2

[0037] The preparation method of electronic-grade ammonium acetate comprises the following main steps:

[0038] 1) Preparation of reaction liquid: uniformly mixing glacial acetic acid and acetone at a volume ratio of 1:1 to obtain a reaction liquid.

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

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

[0041] 4) Product drying: The electronic grade ammonium acetate product was obtained by vacuum drying at 30°C for 6 hours.

[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. The detailed results are shown in Table 1.

[0043] Example 3

[0044] The preparation method of electronic grade ammonium acetate comprises the following main steps:

[0045] 1) Reaction solution preparation: glacial acetic acid and acetone were mixed at a volume ratio of 3:1 to obtain a reaction solution.

[0046] 2) Reaction: ammonia gas was bubbled into the prepared reaction solution, the molar ratio of ammonia gas to glacial acetic acid was 2:1, and the reaction was carried out for 3 hours to obtain a slurry.

[0047] 3) Solid-liquid separation: The obtained slurry was subjected to high-speed centrifugation to obtain a solid ammonium acetate crude product.

[0048] 4) Product drying: The electronic grade ammonium acetate product was obtained by vacuum drying at 45°C for 2 hours.

[0049] 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. The detailed results are shown in Table 1.

[0050] Comparative Example 1

[0051] The preparation method of ammonium acetate comprises the following main steps:

[0052] 1) Reaction solution preparation: glacial acetic acid and acetone were mixed at a volume ratio of 4:1 to obtain a reaction solution.

[0053] 2) Reaction: ammonia gas was bubbled into the prepared reaction solution, the molar ratio of ammonia gas to glacial acetic acid was 1:1, and the reaction was carried out for 2 hours to obtain a slurry.

[0054] 3) Solid-liquid separation: The obtained slurry was subjected to high-speed centrifugation to obtain a solid ammonium acetate crude product.

[0055] 4) Product drying: The electronic grade ammonium acetate product was obtained by vacuum drying at 30°C for 6 hours.

[0056] The electronic-grade ammonium acetate product was tested for content of metal ions using ICP-MS. The detailed results are shown in Table 1.

[0057] Comparative Example 2

[0058] The method for preparing ammonium acetate comprises the following main steps:

[0059] 1) Preparation of reaction solution: uniformly mix glacial acetic acid and acetone in a volume ratio of 1:1 to obtain a reaction solution.

[0060] 2) Reaction: pass ammonia gas into the prepared reaction solution, the molar ratio of ammonia gas to glacial acetic acid being 3:1, and react for 2 hours to obtain a slurry.

[0061] 3) Solid-liquid separation: perform high-speed centrifugation on the obtained slurry to obtain a solid ammonium acetate crude product.

[0062] 4) Product drying: vacuum dry at 35°C for 2 hours to obtain an electronic-grade ammonium acetate product.

[0063] The electronic-grade ammonium acetate product was tested for content of metal ions using ICP-MS. The detailed results are shown in Table 1.

[0064] Comparative Example 3

[0065] The method for preparing ammonium acetate comprises the following main steps:

[0066] 1) Preparation of reaction solution: uniformly mix glacial acetic acid and acetone in a volume ratio of 2:1 to obtain a reaction solution.

[0067] 2) Reaction: pass ammonia gas into the prepared reaction solution, the molar ratio of ammonia gas to glacial acetic acid being 1:1, and react for 2 hours to obtain a slurry.

[0068] 3) Solid-liquid separation: perform high-speed centrifugation on the obtained slurry to obtain a solid ammonium acetate crude product.

[0069] 4) Product drying: vacuum dry at 45°C for 0.5 hours to obtain an electronic-grade ammonium acetate product.

[0070] The electronic-grade ammonium acetate product was tested for content of metal ions using ICP-MS. The detailed results are shown in Table 1.

[0071] Comparative Example 4

[0072] The difference between the example 1 and the example 2 is that the acetone is not added, and actually the glacial acetic acid is directly reacted with the ammonia gas. The reaction speed is fast, difficult to control, and the ammonia gas is introduced into the glacial acetic acid by the aeration head. The ammonium acetate generated at the aeration head will directly block the aeration head, so that the ammonia gas cannot be further introduced into the reaction liquid.

[0073] The main difference between the above examples and the comparative examples is that the ratio of the glacial acetic acid to the acetone in the reaction liquid is different. The acetone is used as a solvent of the glacial acetic acid, and dilutes the glacial acetic acid. If the concentration of the glacial acetic acid is too high, the reaction process will be too fast, the aeration head will be blocked, or a large amount of ammonium acetate will be generated in a short time, which will cause the solidification, affect the diffusion of the ammonia gas in the reaction liquid, and cause a large amount of unreacted acetic acid in the generated ammonium acetate, thereby affecting the purity of the final product of the ammonium acetate. If the concentration of the glacial acetic acid is too low, the single crystal yield will be low, which is not economical. In other process conditions, if the ammonia gas is excessive, a large amount of ammonia gas will be adsorbed in the produced ammonium acetate product. Although the ammonia gas is effectively removed in the next drying process, a large amount of residual ammonia gas will cause low raw material utilization and poor economy, and will also deteriorate the operation environment of the solid-liquid separation and product drying steps. In the product drying process, the difference between the drying temperature and the drying time will cause different amounts of residual acetone and ammonia gas in the ammonium acetate, and then affect the quality of the finally obtained ammonium acetate.

[0074] Table 1. Analysis test results

[0075]

[0076] As can be seen from the results in Table 1, the method provided by the present application can realize 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.

[0077] The above examples describe the preferred embodiments of the present application, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other way. These simple modifications and combinations should also be considered as disclosed by the present application, and belong to the protection scope of the present application. Therefore, the protection scope of the present application patent should be subject to the appended claims.

Claims

1. A method for preparing electronic-grade ammonium acetate, characterized in that, Includes the following steps: S1. Mix glacial acetic acid and acetone evenly, with a volume ratio of glacial acetic acid to acetone of 1~3:1; S2. Ammonia gas is added to the material obtained in S1 to react and a slurry is obtained; wherein the molar ratio of ammonia gas to glacial acetic acid is 1~2:

1. The slurries obtained from S3 and S2 are subjected to solid-liquid separation. The resulting solid phase is then vacuum dried at a temperature of 30-45℃ for 2-6 hours 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, with a purity 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 2:

1.

4. The method according to claim 1, characterized in that: The molar ratio of ammonia to glacial acetic acid in S2 is 1.5:

1.

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

6. The method according to claim 5, characterized in that: The reaction time described in S2 is 3 hours.

7. The method according to claim 1, characterized in that: The drying temperature in S3 is 35℃, and the drying time is 4 hours.

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