Process for the preparation of electronic grade 2-propanol

Abstract

The present application relates to the field of preparation of electronic grade chemical products, and discloses a preparation method of electronic grade 2-propanol.The method comprises the following steps: obtaining crude 2-propanol product by hydrogenation reaction of refined acetone, and obtaining electronic grade 2-propanol by refining treatment of the crude 2-propanol product; and the total concentration of alkali metals and alkaline earth metals in the refined acetone is not higher than 200 ppm.In the present application, the inventors have found that, when preparing 2-propanol product, by controlling the total concentration of alkali metals and alkaline earth metals in the refined acetone to be not higher than 200 ppm, the conversion rate of the refined acetone in the hydrogenation reaction and the selectivity of 2-propanol can be increased.

Description

Technical Field

[0001] This invention relates to the field of electronic-grade chemical product preparation technology, specifically to a method for preparing electronic-grade 2-propanol. Background Technology

[0002] Ultra-high purity reagents are crucial basic functional chemicals in the chip manufacturing process, primarily used for chip cleaning. Their purity and cleanliness are directly related to the yield of integrated circuits. With the widespread adoption of large-scale integrated circuits, higher requirements are being placed on the quality of wet electronic chemicals. Currently, China still relies on imports for G5-grade organic wet electronic chemicals. 2-Propanol used in integrated circuits has strict requirements regarding the content of trace metal cation impurities. Excessively high metal cation content will reduce the yield of chips during the exposure process. Summary of the Invention

[0003] The purpose of this invention is to overcome the problems of low acetone conversion and low selectivity of 2-propanol in the preparation of 2-propanol by existing technology, and the excessively high cation content in the purified 2-propanol, which makes the obtained 2-propanol unable to meet the requirements for the content of metal cations in electronic grade 2-propanol.

[0004] 2-Propanol is prepared by hydrogenating acetone. The resulting 2-propanol has various applications. With the popularization of large-scale integrated circuits, 2-propanol can be used as a wet electronic chemical in integrated circuits. However, integrated circuits have strict requirements on the content of trace metal cation impurities. Through experimental research, the inventors found that the total concentration of alkali metals and alkaline earth metals in acetone affects the content of metal cation impurities in the final 2-propanol. In the experiment, the inventors also found that alkali metals and alkaline earth metals promote the growth of catalyst grains used in the acetone hydrogenation process, reducing the activity of the acetone hydrogenation catalyst. As a result, the crude 2-propanol product requires high equipment and process requirements during purification, making it difficult to obtain electronic-grade 2-propanol that meets the requirements.

[0005] To achieve the above objectives, the present invention provides a method for preparing electronic-grade 2-propanol, the method comprising: obtaining crude 2-propanol product by hydrogenation of purified acetone, and obtaining electronic-grade 2-propanol by purification of the crude 2-propanol product; wherein the total concentration of alkali metals and alkaline earth metals in the purified acetone is not higher than 200 ppm.

[0006] Through the above technical solution, the total concentration of alkali metals and alkaline earth metals in the refined acetone is controlled below 200 ppm in this invention. This not only reduces the content of impurities such as metal cations in the final electronic-grade 2-propanol, but also better increases the conversion rate of refined acetone and the selectivity of 2-propanol in the crude 2-propanol product. Furthermore, it can further reduce the requirements for equipment and energy consumption in the refining process of the crude 2-propanol product. Detailed Implementation

[0007] 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.

[0008] The present invention provides a method for preparing electronic-grade 2-propanol, the method comprising: obtaining crude 2-propanol product by hydrogenation of purified acetone, and obtaining electronic-grade 2-propanol by purification of the crude 2-propanol product; wherein the total concentration of alkali metals and alkaline earth metals in the purified acetone is not higher than 200 ppm.

[0009] In this invention, the inventors discovered that controlling the total concentration of alkali metals and alkaline earth metals in purified acetone to no more than 200 ppm during the preparation of 2-propanol can increase the conversion rate of purified acetone and the selectivity of 2-propanol during the hydrogenation reaction. In experiments, the inventors also found that controlling the total concentration of alkali metals and alkaline earth metals in purified acetone to no more than 200 ppm can also reduce the equipment requirements and energy consumption during the purification process of 2-propanol. Through experimental results, the inventors found that if the concentration exceeds the above range, alkali metals and alkaline earth metals will promote the growth of hydrogenation catalyst crystals during the hydrogenation reaction, reducing the activity of the hydrogenation catalyst. Simultaneously, alkali metals and alkaline earth metals will also increase the equipment and energy requirements during the purification of crude 2-propanol.

[0010] According to some preferred embodiments of the present invention, the total concentration of alkali metals and alkaline earth metals in the refined acetone is not higher than 50 ppm. By employing the aforementioned embodiments, the conversion rate of the refined acetone feedstock in the hydrogenation reaction and the selectivity of the 2-propanol product can be further increased, while reducing the energy consumption of the 2-propanol product during the refining process.

[0011] In this invention, the source of the refined acetone is not particularly limited as long as the purpose of this invention can be achieved. In some preferred embodiments, the acetone raw material is dehydrated and distilled after contacting with an oxidant to remove reducing impurities.

[0012] In this invention, acetone raw material refers to the raw material used to obtain refined acetone. As long as the purpose of this invention can be achieved, the selection of the acetone raw material is not particularly limited. In some embodiments, the purity of the acetone raw material is 95-99.8 wt%. Acetone raw materials within this purity range can be obtained commercially. However, commercially available acetone raw materials contain a lot of impurities, especially alkali metals and alkaline earth metals. The inventors found that the presence of these impurities, especially alkali metals and alkaline earth metals, not only affects the purity of the subsequently obtained 2-propanol, but also affects the conversion rate of acetone obtained from the hydrogenation reaction. In order to obtain refined acetone that meets the requirements, and at the same time better increase the conversion rate of acetone and the selectivity of 2-propanol, the inventors contact the acetone raw material with an oxidant to remove reducing impurities, and then perform dehydration treatment and distillation to obtain the refined acetone.

[0013] According to the present invention, the distillation method is not particularly limited, and distillation can be carried out in a conventional distillation column. In some embodiments, during distillation, the fraction at 54-58°C is collected as the refined acetone. By using the aforementioned embodiments, refined acetone with a low content of impurities such as alkali metals and alkaline earth metals can be obtained.

[0014] According to some preferred embodiments of the present invention, the conditions for distilling acetone include: atmospheric pressure.

[0015] According to some preferred embodiments of the present invention, the distillation conditions for acetone include a distillation vessel temperature of 70-80°C, preferably 72-76°C. Using the aforementioned embodiments, the 54-58°C fraction can be stably collected, reducing equipment requirements while also lowering the content of alkali and alkaline earth metals in refined acetone, increasing the conversion rate of refined acetone and the yield of 2-propanol, and further reducing equipment requirements.

[0016] According to the present invention, when acetone raw material comes into contact with oxidant, the amount of acetone raw material and oxidant can be selected as needed. In order to better achieve the purpose of the present invention, it has been found that in some preferred embodiments, the weight ratio of acetone raw material to oxidant is (1000-10000):1.

[0017] According to the present invention, as long as the purpose of the present invention can be achieved, there are no special restrictions on the contact method between acetone raw material and oxidant. In the present invention, the oxidant and acetone raw material are contacted in a reaction vessel, and there are no special requirements for the temperature. In some preferred embodiments, the temperature when acetone raw material and oxidant are in contact is 0-40°C. There are no special restrictions on the mixing time. In some embodiments, the mixing contact time is 0.5-10h, preferably 3-8h.

[0018] According to the present invention, in some preferred embodiments, the oxidant comprises an oxygen-containing organometallic complex. It has been found that by employing the aforementioned embodiments, not only can reducing impurities and other impurities in acetone feedstock be removed more effectively without introducing new impurities, but the inventors have also found that acetone feedstock treated with the aforementioned oxidant can also remove alkali metals and alkaline earth metals from the acetone feedstock more effectively during distillation.

[0019] According to the present invention, in order to better achieve the objectives of the invention, in some preferred embodiments, the oxidant comprises an oxygen-containing organometallic complex after oxidation treatment. By employing the aforementioned embodiments, the total concentration of alkali metals and alkaline earth metals in refined acetone can be better reduced, while increasing the conversion rate of refined acetone and the yield of 2-propanol, and reducing the energy consumption during the purification of 2-propanol products.

[0020] According to some preferred embodiments of the present invention, the structure of the oxygen-containing organometallic complex after oxidation treatment is shown in formula (1):

[0021]

[0022] In equation (1), R 11 R 12 R 21 R 22 、、R 23 R 24 Each element is independently selected from H, C1-C3 benzyl, alkyl, C1-C2 alkyl-substituted naphthyl, or C1-C2 alkyl-substituted phenyl; n is an integer from 0 to 6; M is selected from one or more of Group VIB metal elements (e.g., Cr, Mo, and W, preferably Mo), Group VIIB metal elements (e.g., Mn, Re, and Tc, preferably Mn), and Group VIII metal elements (e.g., Fe, Co, Ni, Rh, Ru, Pd, and Pt, preferably Co); X is a halogen or acetate.

[0023] In this invention, it can be understood that when n is 0, the epoxy structure in the oxygen-containing organometallic complex represented by formula (1) is a five-membered ring structure, when n is 1, the epoxy structure in the oxygen-containing organometallic complex represented by formula (1) is a six-membered ring structure, and so on.

[0024] In some preferred embodiments, R in equation (1) 11 R 12 R 21 R 22 、、R 23 R 24 There are no special restrictions on the specific types. Considering the availability of raw materials and preparation methods, and at the same time, to better achieve the purpose of this invention, in some preferred embodiments, R in formula (1) 11With R 12 Same; R 21 R 22 、、R 23 With R 24 Same; n is an integer from 0 to 3. Using the aforementioned implementation method, the conversion rate of purified acetone is higher and the yield of 2-propanol is better. The inventors speculate, based on experimental results, that the aforementioned scheme enables some impurities in the acetone raw material to be removed more effectively, which is beneficial for the removal of impurities such as alkali metals and alkaline earth metals during subsequent acetone distillation.

[0025] In this invention, formula (1) is obtained by oxidation of an oxygen-containing organometallic complex, and its structure before oxidation is shown in formula (2):

[0026]

[0027] In equation (2), R 11 R 12 R 21 R 22 、、R 23 With R 24 The definition is the same as in formula (1). Those skilled in the art will understand that the oxygen-containing organometallic complex after oxidation treatment shown in formula (1) is obtained by reacting the corresponding organic ligand with MX2 to obtain the oxygen-containing organometallic complex with the structure shown in formula (2). Then, the oxygen-containing organometallic complex is oxidized under the treatment of oxidants such as permanganate and / or dichromate. For example, the preparation method of the oxygen-containing organometallic complex after oxidation treatment shown in formula (3) is as follows: 2,2-dimethyl-1,3-dioxolane-4,5-diethanol and manganese chloride salt are added in equimolar amounts under an anhydrous and oxygen-free nitrogen atmosphere. A solution containing 2,2-dimethyl-1,3-dioxolane-4,5-diethanol and a solution containing manganese chloride are added and stirred at room temperature for 6 hours. Then, potassium permanganate is added and reacted for 3 hours. After that, the solvent is evaporated to obtain the oxygen-containing organometallic complex after oxidation treatment.

[0028] Those skilled in the art can choose the appropriate reaction and oxidation treatment methods as needed, and the present invention will not elaborate further.

[0029] According to the present invention, in order to better reduce the water content in acetone raw materials, in some embodiments, the dehydration material used in the dehydration treatment includes one or more of anhydrous calcium chloride, molecular sieves, anhydrous sodium carbonate, calcium oxide, water-absorbing resin, and activated carbon. In this application, 4A molecular sieve is used as the dehydration material for the dehydration treatment of acetone as an exemplary illustration of the present invention, but the present invention is not limited thereto.

[0030] According to the present invention, there are no special restrictions on the specific operation of the dehydration treatment. The dehydration material can be filled into the dehydration tower, and then the raw material to be dehydrated can be passed through the dehydration tower. In order to achieve a better dehydration effect, one or more dehydration towers can be used in series. The endpoint of the dehydration treatment of acetone in the present invention is that the water content in the acetone raw material is less than 1500 ppm.

[0031] According to the present invention, in some embodiments, the hydrogenation reaction method includes: carrying out a hydrogenation reaction between purified acetone and hydrogen in a reactor packed with a catalyst.

[0032] According to the present invention, in some embodiments, the catalyst comprises a support and / or an active metal.

[0033] According to some embodiments of the present invention, the carrier is selected from one or more of silica, diatomaceous earth, alumina and activated carbon.

[0034] According to some embodiments of the present invention, the active metal is selected from one or more of nickel, copper and ruthenium.

[0035] In this invention, the method of this invention can reduce the impact on the catalyst, thereby better increasing the conversion rate of acetone and the selectivity of 2-propanol.

[0036] According to the present invention, the conditions for the hydrogenation reaction are not particularly limited as long as the purpose of the present invention can be achieved. In some embodiments, the conditions for the hydrogenation reaction include: a molar ratio of hydrogen to purified acetone of (1-30):1; and a space velocity of purified acetone of 0.1-3 h⁻¹. -1 .

[0037] According to the present invention, in some embodiments, the conditions for the hydrogenation reaction include: a reaction pressure of 1-10 MPa; and a reaction inlet temperature of 80-140°C.

[0038] According to the present invention, in order to obtain electronic grade 2-propanol, in some embodiments, the purification treatment of the crude 2-propanol product includes: dehydrating the crude 2-propanol product and then subjecting it to vacuum distillation to obtain the electronic grade 2-propanol.

[0039] According to the present invention, in some embodiments, the dehydrating material used in the dehydration of crude 2-propanol includes one or more of anhydrous calcium chloride, molecular sieve, anhydrous sodium carbonate, calcium oxide, water-absorbing resin and activated carbon.

[0040] In this invention, there are no special restrictions on the specific operation of crude 2-propanol dehydration. The dehydration material can be loaded into the dehydration tower, and then the raw material to be dehydrated can be passed through the dehydration tower. In order to achieve a better dehydration effect, one or more dehydration towers can be set in series. The endpoint of crude 2-propanol dehydration in this invention is that the water content in crude 2-propanol dehydration is less than 1500 ppm.

[0041] According to the present invention, in some embodiments, the fraction distilled at 45-50°C is collected during vacuum distillation to obtain the electronic-grade 2-propanol. Using the aforementioned embodiments, the purity of the electronic-grade 2-propanol can be better increased.

[0042] According to the present invention, in some embodiments, the conditions for vacuum distillation include: a distillation vessel temperature of 60-74°C and a vacuum degree of 350-500 mbar.

[0043] The present invention will be described in detail below through embodiments.

[0044] In the following examples and comparative examples, the total concentrations of alkali metals and alkaline earth metals were obtained by ICP testing; the proportions of each component were calculated using the gas chromatography area normalization method.

[0045] The purity of (electronic grade) 2-propanol was obtained by gas chromatography.

[0046] Acetone conversion rate = (Percentage of acetone before hydrogenation - Percentage of acetone after hydrogenation) / Percentage of acetone before hydrogenation * 100%;

[0047] The percentage of 2-propanol in the crude 2-propanol product refers to the percentage content of 2-propanol in the sample obtained by gas chromatography area normalization.

[0048] Example 1

[0049] Preparation of oxidant: Equimolar amounts of 2,2-dimethyl-1,3-dioxolane-4,5-diethanol and manganese chloride salt were added to a solution of 2,2-dimethyl-1,3-dioxolane-4,5-diethanol and a solution of manganese chloride under an anhydrous and oxygen-free nitrogen atmosphere. The mixture was stirred at room temperature for 6 hours. Then, potassium permanganate (with a molar ratio of 1:1 to manganese chloride salt) was added, and the reaction was carried out for 3 hours. The solvent was then evaporated to obtain the oxidant for oxidation treatment.

[0050] Acetone raw material with a purity of 99.5 wt% and an oxidant (0.03% of the weight of acetone raw material) are mixed and contacted in a reactor (temperature 30℃, mixing time 5h). The acetone flowing out of the reactor flows into a dehydration tower filled with 4A molecular sieves for dehydration (the water content of the dehydrated acetone is less than 1500 ppm). The dehydrated acetone is then subjected to atmospheric distillation in a distillation tower. During atmospheric distillation, the temperature of the tower bottom is 72℃. The fraction at 54-58℃ is collected during atmospheric distillation to obtain purified acetone.

[0051] Hydrogen gas with a molar ratio of 10:1 and purified acetone were subjected to a hydrogenation reaction in a reactor packed with 5 wt% Cu / SiO2 catalyst. The reaction inlet temperature was set at 110 °C, the reaction pressure at 6 MPa, and the space velocity of purified acetone at 0.8 h⁻¹. -1 After hydrogenation, crude 2-propanol product is obtained. The crude 2-propanol product enters a dehydration tower packed with 4A molecular sieve (the water content of the dehydrated crude 2-propanol is less than 800 ppm). The dehydrated crude 2-propanol is then subjected to vacuum distillation in a distillation tower with a vacuum degree of 350 mbar and a bottom temperature of 72°C. Electronic grade 2-propanol is obtained after vacuum distillation.

[0052] The total concentrations of alkali metals and alkaline earth metals in refined acetone, the conversion rate of acetone, the proportion of 2-propanol in crude 2-propanol product, and the purity of electronic-grade 2-propanol are shown in Table 1.

[0053] Example 2

[0054] The method is the same as in Example 1, except that:

[0055] The weight of the oxidant is 0.04% of the weight of the acetone raw material.

[0056] Everything else is the same as in Example 1.

[0057] The total concentrations of alkali metals and alkaline earth metals in refined acetone, the conversion rate of acetone, the proportion of 2-propanol in crude 2-propanol product, and the purity of electronic-grade 2-propanol are shown in Table 1.

[0058] Example 3

[0059] The method is the same as in Example 1, except that:

[0060] The weight of the oxidant is 0.05% of the weight of the acetone raw material.

[0061] Everything else is the same as in Example 1.

[0062] The total concentrations of alkali metals and alkaline earth metals in refined acetone, the conversion rate of acetone, the proportion of 2-propanol in crude 2-propanol product, and the purity of electronic-grade 2-propanol are shown in Table 1.

[0063] Example 4

[0064] The method is the same as in Example 1, except that:

[0065] Acetone raw material with a purity of 99.5 wt% is fed into a dehydration tower filled with 4A molecular sieve for dehydration (the water content of the dehydrated acetone is less than 1500 ppm). The dehydrated acetone is then subjected to atmospheric distillation in a distillation tower. During atmospheric distillation, the temperature of the bottom of the tower is 72°C. The fraction at 54-58°C is collected during atmospheric distillation to obtain refined acetone.

[0066] Everything else is the same as in Example 1.

[0067] The total concentrations of alkali metals and alkaline earth metals in refined acetone, the conversion rate of acetone, the proportion of 2-propanol in crude 2-propanol product, and the purity of electronic-grade 2-propanol are shown in Table 1.

[0068] Example 5

[0069] The method is the same as in Example 3, except that:

[0070] The oxidant in Example 3 was replaced with an oxidizing metal salt, KMnO4.

[0071] The rest is the same as in Example 3.

[0072] The total concentrations of alkali metals and alkaline earth metals in refined acetone, the conversion rate of acetone, the proportion of 2-propanol in crude 2-propanol product, and the purity of electronic-grade 2-propanol are shown in Table 1.

[0073] Example 6

[0074] The method is the same as in Example 3, except that:

[0075] The temperature of the dehydrated acetone during atmospheric distillation in the distillation column is 90℃.

[0076] The rest is the same as in Example 3.

[0077] The total concentrations of alkali metals and alkaline earth metals in refined acetone, the conversion rate of acetone, the proportion of 2-propanol in crude 2-propanol product, and the purity of electronic-grade 2-propanol are shown in Table 1.

[0078] Example 7

[0079] The method of Example 3 differs in that the acetone raw material is not in contact with the oxidant and is not subjected to atmospheric distillation. That is, the acetone raw material with a purity of 99.5 wt% is pressurized by the raw material pump and flows into a dehydration tower filled with 4A molecular sieve for dehydration (the water content of the dehydrated acetone is less than 1500 ppm) to obtain refined acetone.

[0080] The rest is the same as in Example 3.

[0081] The total concentrations of alkali metals and alkaline earth metals in refined acetone, the conversion rate of acetone, the selectivity of 2-propanol, and the purity of 2-propanol are shown in Table 1.

[0082] Comparative Example 1

[0083] The method of Example 3 differs in that:

[0084] The acetone feedstock was not subjected to atmospheric distillation. That is, the acetone feedstock with a purity of 99.5 wt% was contacted in a reactor with the same oxidant as in Example 1 (0.05% of the weight of the acetone feedstock, and a mixing time of 5 h) (temperature of 25 °C, mixing time of 5 h). The acetone flowing out of the reactor flowed into a dehydration tower filled with 4A molecular sieves for dehydration (the water content of the dehydrated acetone was less than 1500 ppm) to obtain purified acetone.

[0085] The rest is the same as in Example 3.

[0086] The total concentrations of alkali metals and alkaline earth metals in refined acetone, the conversion rate of acetone, the proportion of 2-propanol in crude 2-propanol product, and the purity of 2-propanol are shown in Table 1.

[0087] Table 1

[0088]

[0089] As can be seen from the results in Table 1, Examples 1-7, which use the total concentration of alkali metals and alkaline earth metals of the present invention not exceeding 200 ppm, can better increase the conversion rate of acetone and increase the proportion of 2-propanol in the crude 2-propanol product when preparing electronic-grade 2-propanol.

[0090] 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 electronic-grade 2-propanol, characterized in that, The method includes: After acetone feedstock is contacted with an oxidant to remove reducing impurities, it is sequentially dehydrated and distilled to obtain refined acetone. The refined acetone is then hydrogenated to obtain crude 2-propanol, which is further refined to obtain electronic-grade 2-propanol. The total concentration of alkali metals and alkaline earth metals in the refined acetone is not higher than 200 ppm. The weight ratio of acetone feedstock to oxidant is (1000-10000):

1. The temperature at which the acetone feedstock contacts the oxidant is 0-40℃. The oxidant is an oxygen-containing organometallic complex after oxidation treatment, and the structure of the oxygen-containing organometallic complex after oxidation treatment is shown in formula (3): Equation (3).

2. The preparation method according to claim 1, wherein, During the distillation process, the fraction collected at 54-58℃ is used as the refined acetone.

3. The preparation method according to claim 2, wherein, The conditions for distilling acetone are: Atmospheric pressure; The temperature of the tower bottom is 70-80℃.

4. The preparation method according to claim 3, wherein, The conditions for distilling acetone are: The temperature of the tower bottom is 72-76℃.

5. The preparation method according to claim 1, wherein, The dehydration materials used in the dehydration process are one or more of the following: anhydrous calcium chloride, molecular sieve, anhydrous sodium carbonate, calcium oxide, water-absorbing resin, and activated carbon.

6. The preparation method according to claim 1, wherein, The hydrogenation reaction is carried out by reacting purified acetone with hydrogen in a reactor packed with a catalyst.

7. The preparation method according to claim 6, wherein, The catalyst comprises a support and an active metal.

8. The preparation method according to claim 7, wherein, The carrier is selected from one or more of silica, diatomaceous earth, alumina, and activated carbon; The active metal is selected from one or more of nickel, copper, and ruthenium.

9. The preparation method according to claim 1, wherein, The conditions for the hydrogenation reaction are: The molar ratio of hydrogen to purified acetone is (1-30):1; the space velocity of purified acetone is 0.1-3 h⁻¹. -1 ; The reaction pressure is 1-10 MPa; the reaction inlet temperature is 80-140℃.

10. The preparation method according to claim 1, wherein, The purification process of the crude 2-propanol product is as follows: the crude 2-propanol product is dehydrated and then subjected to vacuum distillation to obtain the electronic grade 2-propanol.

11. The preparation method according to claim 10, wherein, The dehydration material used in the dehydration of crude 2-propanol is one or more of the following: anhydrous calcium chloride, molecular sieve, anhydrous sodium carbonate, calcium oxide, water-absorbing resin, and activated carbon. The fraction collected at 45-50℃ during vacuum distillation is the electronic grade 2-propanol.

12. The preparation method according to claim 10 or 11, wherein, The conditions for vacuum distillation are: The temperature of the column bottom is 60-74℃; the vacuum degree is 350-500mbar.

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