Ultra-clean high-purity acetone, its preparation method and its application

Abstract

The present application relates to the preparation field of cleaning solvents for integrated circuit industry, and particularly relates to a super-clean high-purity acetone and a preparation method and application thereof. The super-clean high-purity acetone has a chemical purity of greater than or equal to 99.99%, a colority of less than or equal to 10 Hazen, and an acid value of less than or equal to 10 ppm; and an organic impurity content of less than or equal to 20 ppm. The preparation method of the super-clean high-purity acetone comprises the following steps: (1) contacting a crude acetone with a mixture containing an oxidizing agent to obtain a first material; (2) contacting the first material with a pH regulator to obtain a second material; and (3) sequentially performing light removal, heavy removal, dehydration, ion removal and filtration on the second material. The super-clean high-purity acetone has a low organic impurity content and a low acid value, and the preparation method of the present application can obtain super-clean high-purity acetone with low organic impurity content and low acid value. The prepared super-clean high-purity acetone can meet the requirements of cleaning solvents for integrated circuit industry.

Description

Technical Field

[0001] This invention relates to the field of preparation of cleaning solvents for the integrated circuit industry, specifically to an ultra-clean high-purity acetone, its preparation method, and its application. Background Technology

[0002] Acetone, also known as dimethyl ketone, has the molecular formula C3H6O. It is the simplest saturated ketone and is readily soluble in water and organic solvents such as methanol, ethanol, ether, chloroform, and pyridine. Industrially, it is an excellent solvent, mainly used in the explosives, plastics, rubber, fiber, leather, oil, and paint industries.

[0003] In the semiconductor industry, acetone is also an important solvent. Its low boiling point makes it commonly used as a cleaning agent and desiccant. Semiconductor-grade acetone, specifically ultra-pure high-purity acetone, has a significant impact on semiconductor yield. Therefore, it places extremely high demands on product quality, particularly regarding organic impurities, water content, metal ions, and particulate residues. Compared to traditional acetone products, the preparation process for ultra-pure high-purity acetone is more complex and rigorous to ensure high quality. Furthermore, with the further development of the integrated circuit industry and the increasing precision and miniaturization of chips, the requirements for ultra-pure high-purity acetone will continue to rise. Therefore, the development of ultra-pure high-purity acetone preparation processes is extremely urgent.

[0004] However, there are few existing patents and literature reports on ultra-clean, high-purity acetone, especially regarding the removal of organic impurities. For example, CN201317750Y reports a method for obtaining ultra-clean, high-purity acetone using only one distillation, but this method has limited effectiveness in removing organic impurities, and some aldehydes will still remain in the product, affecting its quality. Another example is CN103601624B, which uses an oxidation process to first oxidize the acetone and then distill it to remove organic impurities, but this method results in a high acid value in the product, which also affects its quality.

[0005] Therefore, in response to the problems that arise during the preparation of ultra-clean high-purity acetone, especially the poor product quality caused by the ineffective removal of organic impurities, it is necessary to develop a better method for purifying ultra-clean high-purity acetone. Summary of the Invention

[0006] The purpose of this invention is to provide a new ultra-clean, high-purity acetone that can be used as a cleaning solvent in the integrated circuit industry.

[0007] The first aspect of this invention provides an ultra-clean, high-purity acetone with a chemical purity ≥99.99%, a color ≤10 Hazen, an acid value ≤10ppm, and an organic impurity content ≤20ppm.

[0008] A second aspect of the present invention provides a method for preparing the ultra-clean, high-purity acetone described herein, the method comprising:

[0009] (1) Crude acetone is contacted with a mixture containing an oxidant to obtain the first material;

[0010] (2) The first material is brought into contact with a pH adjuster to obtain the second material;

[0011] (3) The second material is subjected to light removal, heavy removal, dehydration, deionization and filtration in sequence.

[0012] The third aspect of this invention provides the application of the ultra-clean high-purity acetone described in this invention, and / or the ultra-clean high-purity acetone prepared by the preparation method described in this invention, in integrated circuits.

[0013] Through the above technical solution, the ultra-clean high-purity acetone of the present invention not only has a low content of organic impurities, but also a low acid value. Furthermore, the preparation method of the present invention can obtain ultra-clean high-purity acetone with low organic impurity content and low acid value. The prepared ultra-clean high-purity acetone can meet the requirements of cleaning solvents used in the integrated circuit industry. Attached Figure Description

[0014] Figure 1 This is a schematic flowchart of a method for preparing ultrapure high-purity acetone in one embodiment of the present invention.

[0015] Explanation of reference numerals in the attached figures

[0016] 1. Crude acetone 2. Mixed materials 3. First material

[0017] 4. Alkali solution 5. Second material 6. Light component

[0018] 7. Bottom product; 8. Heavy components; 9. Top distillate.

[0019] 10. Water 11. Concentration side product 12. Bottom material

[0020] 13. Ultra-clean high-purity acetone product ①, First stirred tank ②, Second stirred tank

[0021] ③ Light component removal tower ④ Heavy component removal tower ⑤ Pervaporation unit

[0022] ⑥ Detachment tower ⑦ Filtration system Detailed Implementation

[0023] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0024] In this invention, "purity" refers to a percentage by mass; the unit "ppm" refers to a mass content.

[0025] The first aspect of this invention provides an ultra-clean, high-purity acetone with a chemical purity ≥99.99%, a color ≤10 Hazen, an acid value ≤10ppm, and an organic impurity content ≤30ppm.

[0026] The ultra-clean, high-purity acetone of this invention has not only low organic impurity content, but also low acid value.

[0027] According to the present invention, in some embodiments, the chemical purity of the ultra-clean high-purity acetone is 99.9972-99.9991%, preferably 99.9985-99.9991%, and more preferably 99.9989-99.9991%.

[0028] According to the present invention, in some embodiments, the acid value of ultrapure high-purity acetone is 4-10 ppm, preferably 4-6 ppm.

[0029] According to the present invention, in some embodiments, the content of organic impurities in the ultrapure high-purity acetone is ≤20ppm, preferably 9-15ppm, and more preferably 9-11ppm.

[0030] According to some embodiments of the present invention, the organic impurity includes at least one selected from isopropanol, acetaldehyde, propionaldehyde, propylene, isopropyl ether, and methanol.

[0031] According to the present invention, in some embodiments, the ultrapure acetone contains ≤100ppm of water, preferably 50-78ppm, more preferably 50-65ppm, and even more preferably 50-60ppm.

[0032] According to some embodiments of the present invention, the content of a single metal ion in the ultrapure high-purity acetone is ≤50ppt.

[0033] According to the present invention, in some embodiments, the ultrapure acetone contains ≤10 particles larger than 0.5 μm / ml, for example, 5, 6, 7 or 8 particles / ml.

[0034] According to the present invention, in some embodiments, the content of evaporation residue in the ultrapure acetone is ≤1 ppm, for example, 0.2 ppm, 0.3 ppm, 0.4 ppm, 0.5 ppm, 0.6 ppm, 0.7 ppm or 0.8 ppm.

[0035] A second aspect of this invention provides a method for preparing ultrapure, high-purity acetone, the method comprising:

[0036] (1) The crude acetone product is first contacted with a mixture containing an oxidant to obtain the first material;

[0037] (2) The first material is brought into a second contact with a pH adjuster to obtain the second material;

[0038] (3) The second material is subjected to light removal, heavy removal, dehydration, deionization, and filtration.

[0039] The preparation method of the present invention can obtain ultra-clean high-purity acetone with low organic impurity content and acid value. The prepared ultra-clean high-purity acetone can meet the requirements of cleaning solvents used in the integrated circuit industry.

[0040] According to the present invention, in step (1), the conditions for the first contact include: the crude acetone and the mixture containing the oxidant are first mixed in a static mixer, and the mixed material is then mixed in a stirred tank. Using the aforementioned embodiments, the mixture can better interact with the impurities in the crude acetone, ultimately resulting in an acetone product with higher purity and lower levels of organic impurities, evaporation residue, single metal ions, water content, and color.

[0041] According to the present invention, in some embodiments, the conditions for the second mixing include: a mixing temperature of 15-50°C, for example 15°C, 25°C, 35°C, 40°C, 45°C or 50°C, preferably 35-50°C.

[0042] According to some embodiments of the present invention, the conditions for the second mixing include a mixing time of 1-4 hours.

[0043] According to the present invention, in some embodiments, in step (2), the conditions for the second contact include: the first material and the pH adjuster first enter a static mixer for a third mixing, and then enter a stirred tank for a fourth mixing. Using the aforementioned embodiments, an acetone product with higher purity and lower content of organic impurities, evaporation residue, single metal ions, water content, and color can ultimately be obtained.

[0044] According to the present invention, the conditions for the first and third mixing are not particularly limited, and are generally carried out at room temperature (10-30°C) until the mixing is uniform. The present invention will not elaborate further. The construction of the static mixer is not particularly limited and is a conventional static mixer in the art.

[0045] According to the present invention, in some embodiments, the conditions for the fourth mixing include: a mixing temperature of 15-50°C, for example 15°C, 25°C, 35°C, 40°C, 45°C or 50°C, preferably 20-30°C.

[0046] According to the present invention, in some embodiments, the conditions for the fourth mixing include a mixing time of 0.5h-1h.

[0047] According to the present invention, the mixture containing the oxidant refers to a mixture formed by mixing an oxidant or other reagent with water. In some embodiments, the oxidant is selected from at least one of potassium permanganate, hydrogen peroxide, potassium dichromate, potassium perchlorate, potassium chlorite, potassium chlorate, potassium chlorate, and potassium hypochlorite, preferably potassium permanganate and / or hydrogen peroxide. Using the foregoing embodiments, acetone products with higher purity and lower organic impurity content can be prepared.

[0048] According to the present invention, in some embodiments, the content of the oxidant in the mixture is 1-20 wt%. Using the aforementioned embodiments, acetone products with higher purity and lower organic impurity content can be prepared.

[0049] According to some preferred embodiments of the present invention, when the oxidant is hydrogen peroxide, the content of the oxidant in the mixture is 2-20 wt%, for example, 2.5 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, or any combination of two of the above values. Using the foregoing embodiments, acetone products with higher purity and lower organic impurity and evaporation residue content can be prepared.

[0050] According to some preferred embodiments of the present invention, when the oxidant is hydrogen peroxide, the content of the oxidant in the mixture is 1-10 wt%, for example, 1 wt%, 1.5 wt%, 2.5 wt%, 5 wt%, 7 wt%, 10 wt%, or any combination of two of the above values. Using the foregoing embodiments, acetone products with higher purity and lower organic impurity and evaporation residue content can be prepared.

[0051] According to some preferred embodiments of the present invention, when the oxidant is potassium permanganate, the content of the oxidant in the mixture is 1.5-4 wt%, for example, 1.5 wt%, 2.5 wt%, 4 wt%, or any combination of two of the above values.

[0052] According to the present invention, in some embodiments, the mixture containing the oxidant also contains a stabilizer. By employing the aforementioned embodiments, the oxidant in the mixture can react more stably with some impurities in the crude acetone, while ensuring the stable progress of subsequent steps, ultimately yielding an acetone product with higher purity and lower levels of organic impurities, evaporation residue, single metal ions, water content, and color.

[0053] According to the present invention, in some embodiments, the stabilizer is selected from at least one of sodium tripolyphosphate, sodium polymethacrylate, sodium gluconate, and sodium metasilicate. By employing the aforementioned embodiments, the oxidant in the mixture can react more stably with some impurities in the crude acetone, while ensuring the stable progress of subsequent steps, ultimately yielding an acetone product with higher purity and lower levels of organic impurities, evaporation residue, single metal ions, water content, and color.

[0054] According to the present invention, in some preferred embodiments, the stabilizer is selected from sodium tripolyphosphate. By employing the aforementioned embodiments, an acetone product with higher purity and lower content of organic impurities, evaporation residue, single metal ions, water content, and color can be obtained.

[0055] According to the present invention, the amount of the mixture is not particularly limited as long as the purpose of the present invention can be achieved. Preferably, the mass ratio of the crude acetone to the mixture is (0.001-0.01):1, for example, 0.001:1, 0.003:1, 0.005:1, 0.007:1 or 0.01:1. By adopting the foregoing embodiments, an acetone product with higher purity and lower content of organic impurities, evaporation residue, single metal ions, water content and color can be obtained.

[0056] According to the present invention, in some embodiments, the chemical purity of the crude acetone is 98.5-99.9%. The preparation method of the present invention can further improve the chemical purity of the aforementioned crude acetone.

[0057] According to the present invention, as long as the purpose of the present invention can be achieved, the amount of pH adjuster used in step (2) is not particularly limited. Preferably, the amount of pH adjuster added is such that the pH value of the second material is 7-10.

[0058] According to the present invention, in some of the fourteen embodiments, the pH adjuster is selected from an alkaline solution, wherein the alkaline solution refers to a solution formed by an alkaline substance and water, preferably the content of the alkaline substance in the alkaline solution is 0.5-5 mol / L, and preferably the alkaline substance in the alkaline solution is selected from at least one of sodium hydroxide, potassium hydroxide, and ammonium hydroxide. By using the foregoing embodiments, an acetone product with higher purity and lower content of organic impurities, evaporation residue, single metal ions, water content, and color can be obtained.

[0059] According to the present invention, in order to remove impurity components with a boiling point lower than that of acetone during the removal of light components, in some embodiments, the conditions for the removal of light components include: an operating pressure of 0-50 kPa (gauge pressure).

[0060] According to the present invention, in some embodiments, the conditions for removing light components include a reflux ratio of 2-20, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 17, 20, or any combination of two of the above values. This can better increase the purity of the final acetone product.

[0061] According to some preferred embodiments of the present invention, the conditions for removing light components include a reflux ratio of 8-15. Using the aforementioned embodiments, the purity of the final acetone product can be better increased, while the recovery rate of the acetone product can also be increased.

[0062] According to some preferred embodiments of the present invention, the conditions for removing light components include a bottom temperature of 56.6-68.1°C.

[0063] According to the present invention, the deweighting treatment is mainly for removing impurity components with boiling points higher than those of acetone products. As long as the purpose of the present invention can be achieved, the conditions for the deweighting treatment are not particularly limited. In some embodiments, the deweighting conditions include an operating pressure of 0 kPa-50 kPa (absolute pressure).

[0064] According to some preferred embodiments of the present invention, the conditions for deweighting include: a reflux ratio of 0.2-5, for example, 0.2, 1, 2, 3, 4, 5, or any two of the above values.

[0065] According to the present invention, in some embodiments, the conditions for deweighting include: a tower top temperature of 55.7-68.0°C.

[0066] According to some preferred embodiments of the present invention, a coarse filtration step is provided between the removal of light and heavy components; the coarse filtration is performed using a filter with a filter specification of no more than 1 micrometer. By employing the aforementioned embodiments, an acetone product with higher purity and lower evaporation residue content, particle size (≥0.5μm), and water content can be obtained.

[0067] According to some preferred embodiments of the present invention, the dehydration method is pervaporation.

[0068] According to the present invention, the pervaporation separation method refers to separation using a membrane. In some preferred embodiments, the operating conditions of the pervaporation membrane separation method include an operating pressure of 0-8 bar.

[0069] According to some preferred embodiments of the present invention, the operating conditions of the pervaporation membrane separation method include: an operating temperature of 56.6-138.2°C, wherein the operating temperature refers to the corresponding inlet temperature of the membrane.

[0070] According to some preferred embodiments of the present invention, the conditions for pervaporation include: the operating pressure on the permeation side is -100 to -80 kPa (absolute pressure).

[0071] According to the present invention, the method of deionization is not particularly limited as long as the purpose of the present invention can be achieved. In some embodiments, the deionization is carried out in the presence of an ion exchange resin, wherein the ion exchange resin can be a hydrogen-form strong acid cation exchange resin and / or a hydroxide-form strong base anion exchange resin. In this invention, an ion exchange resin of type Amberjet UP6040 is used for example description, but the present invention is not limited thereto.

[0072] According to the present invention, the filtration system used for filtration includes: a multi-stage series filter element made of PTFE, preferably with progressively increasing filtration precision of the multi-stage series filter element, for example, using a series of 4-stage filter elements with progressively increasing filtration precision. Specifically, PTFE filter elements with filtration specifications of 500nm, 200nm, 100nm and 50nm are used for filtration.

[0073] The third aspect of this invention provides the application of the ultra-pure high-purity acetone of this invention and / or the ultra-pure high-purity acetone prepared by the preparation method of this invention in integrated circuits.

[0074] The ultra-clean, high-purity acetone of this invention can meet the requirements for cleaning solvents used in the integrated circuit industry.

[0075] According to the present invention, such as Figure 1As shown, in some embodiments, the preparation method of ultra-clean high-purity acetone includes: a batch of industrial-grade crude acetone 1, which is mixed with a mixture of oxidant 2 (the remainder being water) in a static mixer (not shown) and then fed into a first stirred tank ①. After mixing for 3 hours, a first material 3 is obtained; the first material 3 is mixed with a pH adjuster in a static mixer (not shown) and then fed into a second stirred tank ②. After mixing, a second material 5 is obtained; the second material 5 enters a light component removal tower ③, where light component 6 is obtained at the top; the bottom product 7 is filtered through a 1-micron filter (not shown) and then enters a heavy component removal tower ④. The bottom product 8 of the heavy component removal tower ④ is obtained; the top distillate 9 obtained from the heavy component removal tower ④ enters a pervaporation device ⑤ for pervaporation, where water 10 is obtained on the pervaporation side, and the concentrated product 11 enters a container filled with Amberjet... Deionization is carried out in the ion exchange resin deionization tower ⑥ of UP6040; the bottom material 12 of the deionization tower ⑥ is filtered through the filtration system ⑦ to obtain ultra-clean high-purity acetone product 13.

[0076] The present invention will be described in detail below through examples. In the following examples, the purity of the ultra-clean high-purity acetone product and the content of organic impurities were determined by HPLC; single metal ions were determined by ICP-MS; particulate matter (≥0.5μm) was determined online by a counter; color was determined by a colorimeter; acid value (converted to acetic acid) was determined by a titrator; water content was determined by a Karl Fischer titrator; and evaporation residue was determined by the general method of national standard GB / T 9740-2008.

[0077] Example 1

[0078] A batch of superior industrial-grade crude acetone 1 (chemical purity 99.5%, water content 2560ppm, total aldehyde impurities 35ppm) was mixed with a mixture 2 (the remainder being water) containing 2.5wt% potassium permanganate and 2.5wt% sodium tripolyphosphate, and then fed into the first stirred tank ①. The amount of mixture 2 added was 0.005 times the mass of crude acetone 1. After mixing at 40℃ for 3 hours, the first material 3 was obtained.

[0079] The first material 3 and the alkaline solution 4 containing 2 mol / L potassium hydroxide are first mixed in a static mixer (not shown) and then pumped into the second stirred tank ②. The pH value in the second stirred tank ② is controlled to be 8. After mixing at 25°C for 0.5 h, the second material 5 is obtained.

[0080] The second material 5 enters the light component removal tower ③. The operating pressure of the light component removal tower ③ is 25 kPa, the reflux ratio is 10, and the temperature of the tower bottom is controlled at 62.8℃. Light component 6 is obtained at the top of the tower. The product 7 in the tower bottom is first filtered through a 1-micron filter (not shown) and then enters the heavy component removal tower ④. The operating pressure of the heavy component removal tower ④ is 25 kPa, the reflux ratio is 2, and the temperature of the tower top is controlled at 62.4℃. Heavy component 8 is obtained in the tower bottom.

[0081] The distillate 9 obtained from the heavy component removal column ④ enters the pervaporation unit ⑤ for pervaporation. The operating pressure is 5 bar, the corresponding membrane inlet temperature is 120℃, and the operating pressure on the permeate side is -99 kPa. Water 10 is obtained on the permeate side, and the product 11 on the concentration side enters the deionization column ⑥ filled with Amberjet UP6040 ion exchange resin for deionization. The bottom material 12 of the deionization column ⑥ passes through the filtration system ⑦ (composed of four-stage PTFE filter cartridges in series; the specifications of the four-stage PTFE filter cartridges are 200nm, 100nm, 50nm and 15nm respectively) to obtain ultra-clean high-purity acetone product 13.

[0082] The characteristics of ultra-clean high-purity acetone product 13 are shown in Table 1.

[0083] Example 2

[0084] The method of Example 1 is followed, except that pervaporation is carried out in the pervaporation apparatus ⑤ at an operating pressure of 2 bar; otherwise, it is the same as in Example 1, and ultra-clean high-purity acetone product 13 is obtained.

[0085] The characteristics of ultra-clean high-purity acetone product 13 are shown in Table 1.

[0086] Example 3

[0087] The method of Example 1 was followed, except that the reflux ratio of the heavy component removal tower ④ was 0.5; the rest was the same as in Example 1, and ultra-clean high-purity acetone product 13 was obtained.

[0088] The characteristics of ultra-clean high-purity acetone product 13 are shown in Table 1.

[0089] Example 4

[0090] The method of Example 1 was followed, except that 2.5 wt% hydrogen peroxide was used to replace the mixture containing 2.5 wt% potassium permanganate; the rest was the same as in Example 1, and ultra-clean high-purity acetone product 13 was obtained.

[0091] The characteristics of ultra-clean high-purity acetone product 13 are shown in Table 1.

[0092] Example 5

[0093] The method of Example 1 was followed, except that 10 wt% hydrogen peroxide was used to replace the mixture containing 2.5 wt% potassium permanganate; the rest was the same as in Example 1, and ultra-clean high-purity acetone product 13 was obtained.

[0094] The characteristics of ultra-clean high-purity acetone product 13 are shown in Table 1.

[0095] Example 6

[0096] The method of Example 1 was followed, except that the mixture was carried out at 5°C for 0.5 h to obtain the first material 3; the rest was the same as in Example 1, and the ultra-clean high-purity acetone product 13 was obtained.

[0097] The characteristics of ultra-clean high-purity acetone product 13 are shown in Table 1.

[0098] Example 7

[0099] The method of Example 1 is the same, except that the product 7 in the bottom column is not filtered through a 1-micron filter (not shown) and directly enters the heavy component removal column ④; the rest is the same as in Example 1, and ultra-clean high-purity acetone product 13 is obtained.

[0100] The characteristics of ultra-clean high-purity acetone product 13 are shown in Table 1.

[0101] Example 8

[0102] Following the method of Example 1, except that the mixture 2 does not contain sodium tripolyphosphate; otherwise, it is the same as in Example 1, and an ultra-clean high-purity acetone product 13 is obtained.

[0103] The characteristics of ultra-clean high-purity acetone product 13 are shown in Table 1.

[0104] Comparative Example 1

[0105] The method is the same as in Example 1, except that:

[0106] The first material 3 is directly fed into the light component removal tower ③ for subsequent operations; the rest is the same as in Example 1, and acetone product is obtained.

[0107] The characteristics of acetone products are shown in Table 1.

[0108] Table 1

[0109]

[0110] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing super-clean high-purity acetone, characterized by, The preparation method comprises: (1) first contacting the crude acetone with a mixture containing an oxidizing agent to obtain a first material; (2) second contacting the first material with a pH regulator to obtain a second material; (3) performing light removal, heavy removal, dehydration, ion removal and filtration on the second material; In step (2), the conditions of the second contacting comprise: first mixing the first material and the pH regulator in a static mixer, and then fourth mixing in a stirred tank. The mixture containing the oxidizing agent further contains a stabilizer, and the stabilizer is at least one selected from sodium tripolyphosphate, sodium polymethacrylate, sodium gluconate and sodium metasilicate.

2. The preparation method according to claim 1, wherein, In step (1), the conditions of the first contacting comprise: first mixing the crude acetone and the mixture containing the oxidizing agent in a static mixer, and then second mixing in a stirred tank; and / or The conditions of the fourth mixing comprise: a mixing temperature of 15-50°C, and / or a mixing time of 0.5h-1h.

3. The production method according to claim 2, wherein, The conditions of the second mixing comprise: a mixing temperature of 15-50°C, and / or a mixing time of 1-4h.

4. The preparation method according to claim 1, wherein, The pH value of the second material is 7-10; And / or The pH regulator is selected from lye.

5. The preparation method according to claim 4, wherein, The content of the alkaline substance in the lye is 0.5-5mol / L; and / or The alkaline substance in the lye is at least one selected from sodium hydroxide, potassium hydroxide and ammonium hydroxide.

6. The preparation method according to claim 1, wherein, The oxidizing agent is at least one selected from potassium permanganate, hydrogen peroxide, potassium dichromate, potassium perchlorate, potassium chlorite, potassium chlorate and potassium hypochlorite; and / or The content of the stabilizer in the mixture is 1-20wt%; and / or The mass ratio of the crude acetone to the mixture is (0.001-0.01):1; and / or The chemical purity of the crude acetone is 98.5-99.9%.

7. The production method according to claim 1, wherein The content of the oxidizing agent in the mixture is 1-20wt%.

8. The preparation method according to claim 1, wherein, The conditions of the light removal comprise: an operating pressure of 0-50kPa; and / or, a reflux ratio of 2-20 and / or, a column bottom temperature of 56.6-68.1°C; and / or The conditions of the heavy removal comprise: an operating pressure of 0kPa-50kPa; and / or, a reflux ratio of 0.2-5; and / or, a column top temperature of 55.7-68.0°C.

9. The preparation method according to claim 1, wherein, A rough filtration step is arranged between the light removal and the heavy removal, and the rough filtration is performed by using a filter with a filter specification not greater than 1 micron.

10. The preparation method according to claim 1, wherein, The dehydration method is a pervaporation method; And / or The ion removal is performed in the presence of ion exchange resin; and / or The filter system used in the filtration comprises: a multi-stage filter core with a material of PTFE.

11. The preparation method according to claim 10, wherein, The conditions of the pervaporation include: the operating pressure of the pervaporation is 0-8 bar; and / or, the operating temperature is 56.6-138.2 DEG C; and / or, the operating pressure of the permeation side is -100 - -80 kpa; and / or The filter precision of the filter core in the multi-stage series connection is increased step by step.

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