Method for removing trace acetone in high-purity isopropanol

Abstract

The invention provides a method for removing acetone in isopropanol. The method comprises the following steps: S1, converting acetone in isopropanol into acetoxime; and S2, rectifying the product obtained in the step S1. According to the method disclosed by the invention, the acetone is removed by innovatively converting the acetone in the isopropanol into acetoxime which is greatly different from the isopropanol in boiling point, the ppm-level acetone in the isopropanol can be effectively removed, the removal rate can reach 100%, and the content of the acetone is as low as 0 ppm through gas chromatography detection. Acetone oxime and other impurities can be almost completely removed in a conventional rectification, ion exchange or adsorption mode, so that the high-purity electronic-grade isopropyl alcohol is obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor manufacturing, and in particular relates to a method for removing trace acetone in high-purity isopropanol. Background Art

[0002] Isopropyl alcohol (IPA) is an important cleaning agent in semiconductor products. The specifications and grades of isopropyl alcohol are also very strict in high-specification process applications. Acetone, an impurity in isopropyl alcohol, is an important indicator. A trace amount of acetone residue affects the subsequent semiconductor process and may cause problems such as particle defects in the chip. Therefore, the acetone content is related to the quality of isopropyl alcohol products. High-grade isopropyl alcohol products generally require an acetone content of less than 5ppm.

[0003] Since the boiling point of acetone is close to that of isopropanol (56.5℃ / 82.5℃), IPA itself will undergo a trace oxidation reaction to generate acetone when it comes into contact with air during storage and production. The conventional distillation method has a high cost for removing ppm-level acetone, and IPA is prone to oxidation reaction to generate trace acetone under high temperature conditions during the removal process. Therefore, it is very important to optimize and develop new process methods to remove acetone from isopropanol.

[0004] Chinese patent applications CN112624902A and CN114409508A disclose a method for removing acetone by adsorbing acetone using alkaline solid particles composed of activated alumina, etc. The acetone removal rate reaches 98%, and the acetone content can be lower than 2ppm. However, for extremely demanding semiconductor production processes, there is still room for further reduction of the acetone content. Summary of the invention

[0005] Based on this, the object of the present invention is to provide a method for removing trace acetone in high-purity isopropanol, which is simple and easy to operate, can completely remove acetone, and the tested acetone content is as low as 0 ppm.

[0006] To achieve the above object, the present invention adopts the following technical solution.

[0007] A method for removing acetone from isopropanol comprises the following steps: S1. converting the acetone in the isopropanol into acetone oxime; S2. distilling the product obtained in step S1.

[0008] In some embodiments, step S1 is to react isopropanol containing acetone with hydroxylamine and / or hydroxylamine salt.

[0009] In some preferred embodiments, the molar ratio of the hydroxylamine and / or hydroxylamine salt to acetone is (1.5-5):1.

[0010] In some embodiments, step S1 is to contact the isopropanol containing acetone with a carrier connected with a hydroxylamine group, so that the acetone reacts with the hydroxylamine group. This method can avoid introducing hydroxylamine or hydroxylamine salt and water into the isopropanol system.

[0011] In some embodiments, the carrier is a cation exchange resin; preferably, the carrier is a macroporous strong acid cation resin.

[0012] Preferably, step S1 comprises the following steps: (1) subjecting hydroxylamine to a pretreatment reaction with a cation exchange resin to obtain a cation exchange resin connected with a hydroxylamine group; (2) washing and drying the cation exchange resin connected with a hydroxylamine group; and (3) using the cation exchange resin obtained in step (2) to perform column chromatography on isopropanol containing acetone.

[0013] In some embodiments, the pretreatment reaction in step (1) is: soaking the cation exchange resin in a hydroxylamine solution for 2 hours to 48 hours; and / or,

[0014] The flow rate of the isopropanol containing acetone during the treatment process of step (3) is 1 BV / h to 20 BV / h.

[0015] In some embodiments, the concentration of the hydroxylamine solution is 50 wt %, and the mass ratio of the hydroxylamine solution to the cation exchange resin is 1:1 to 1:5.

[0016] In some embodiments, the distillation in step S2 is batch distillation.

[0017] In some embodiments, the distillation temperature is 90°C to 110°C.

[0018] In some embodiments, the method further comprises step S3, wherein step S3 is to perform column chromatography on the distillation product using a cation exchange resin.

[0019] In some embodiments, the step S3 is to treat the distillation product using molecular sieve or activated carbon.

[0020] In some embodiments, the molecular sieve is at least one of clinoptilolite, mordenite, Y-type zeolite, Beta-type zeolite, and MFI-type zeolite; and / or,

[0021] The activated carbon is selected from at least one of columnar particles and coconut shell particles, and the particle size of the activated carbon is 0.5 mm to 6 mm.

[0022] In some embodiments, the cation exchange resin is pretreated as follows before use: the cation exchange resin is soaked in a salt solution of a chelating metal for 2 hours to 48 hours, and then washed and dried; the salt is selected from at least one of nitrate, hydrochloride and sulfate; and / or,

[0023] The flow rate of the distillation product during the treatment process is 1 BV / h to 20 BV / h.

[0024] In some embodiments, the concentration of the chelated metal nitrate solution is 10 wt %, and the mass ratio of the chelated metal nitrate solution to the cation exchange resin is 1:1 to 1:5.

[0025] In some embodiments, the chelated metal is selected from at least one of Ni, Co, Ca, Zn, Fe, Cu, and Mg; more preferably, the chelated metal is selected from at least one of Ni and Co.

[0026] After the treatment in step S3, the hydroxylamine and acetone oxime introduced in the previous step can be almost completely removed, and the contents of the two impurities are reduced to 0 ppm.

[0027] The present invention innovatively removes acetone by converting acetone in isopropanol into acetone oxime having a large difference in boiling point from isopropanol. The method of the present invention can effectively remove acetone at the ppm level in isopropanol, and the removal rate can reach 100%. The acetone content is as low as 0ppm by gas chromatography. Different from isopropanol and acetone (conventional hydrocarbon oxygen type organic matter), acetone oxime, as a nitrogen-containing organic matter, has higher polarity and more adsorbability, and is easy to separate and remove. Therefore, after acetone is converted into acetone oxime and then subjected to conventional distillation, the content of acetone oxime in the system can be reduced to less than 10ppm. Further, acetone oxime and other impurities can be almost completely removed by ion exchange or adsorption, so as to obtain isopropanol of high-purity electronic grade specification level.

[0028] In addition, the materials used in the method of the present invention are mainly non-metallic materials, which can better avoid the introduction of metal ions caused by metal substances such as metal oxides contacting high-purity isopropyl alcohol. The method can not only remove organic impurities, but also have an ion purification effect on high-purity isopropyl alcohol, and simultaneously achieve the removal of purity and metal impurities. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The gas chromatogram of the product obtained in Example 3 is shown in FIG. DETAILED DESCRIPTION

[0030] The experimental methods in the following examples of the present invention, where no specific conditions are specified, are usually carried out under conventional conditions or under conditions recommended by the manufacturers. The various commonly used chemical reagents used in the examples are all commercially available products.

[0031] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0032] The terms "including" and "having" and any variations thereof of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, device, product or equipment comprising a series of steps is not limited to the listed steps or modules, but may optionally include steps not listed, or may optionally include other steps inherent to these processes, methods, products or equipment.

[0033] In the present invention, the term "multiple" refers to two or more than two. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0034] The following is a description of the process in conjunction with specific examples. In the following examples and comparative examples, the IPA raw materials are all raw materials from the same batch containing 250 ppm of acetone; and the concentrations of the reagents are mass concentrations.

[0035] Example 1

[0036] ①IPA raw material (containing acetone 250ppm) was mixed with 50% hydroxylamine aqueous solution, m(IPA):m(hydroxylamine)=1000:1, and stirred for 2h. ②After the reaction, the mixture was further distilled and purified, using intermittent distillation, adding materials to the bottom of the kettle, and the distillation temperature was 90°C. The middle 10-80% fraction was collected to obtain the fraction, which was the sample of Example 1.

[0037] Example 2

[0038] ①IPA raw material, mixed with 50% hydroxylamine aqueous solution, m(IPA):m(hydroxylamine)=1000:1, stirred for reaction for 2h. ②After the reaction, the mixture was further distilled and purified, the distillation method used intermittent distillation, the bottom of the kettle was added, the distillation temperature was 90°C, and the middle 10-80% fraction was collected. ③The obtained fraction was then treated with a cation exchange resin column, the treatment volume was 10BV, the flow rate was 10BV / h, and the sample of Example 2 was obtained after the treatment was completed.

[0039] Example 3

[0040] ①Use 50% hydroxylamine solution to soak macroporous strong acid cation exchange resin, the soaking ratio is m (50% hydroxylamine): m (cationic resin) = 1: 1, soaking time is 1 day, after soaking, rinse the resin with pure water, and then use vacuum drying, vacuum drying at 45 ° C for 6h, and use it after treatment. ②The vacuum-dried resin is used to treat IPA raw materials in a column-passing manner, with a processing capacity of 10BV and a flow rate of 10BV / h. ③After the column is completed, further distillation and purification are performed, and the distillation method uses intermittent distillation, the bottom of the kettle is charged, the distillation temperature is 90 ° C, and the middle 10-80% fraction is collected to obtain the fraction, which is the sample of Example 3.

[0041] Example 4

[0042] ①Use 50% hydroxylamine solution to soak macroporous strong acid cation exchange resin, the soaking ratio is m (50% hydroxylamine): m (cation resin) = 1: 1, soaking time is 1 day, after soaking, rinse the resin with pure water, and then use vacuum drying, vacuum drying at 45 ° C for 6h, and use it for use after treatment. ②The vacuum-dried resin is used to treat IPA raw materials by column, with a processing capacity of 10BV and a flow rate of 10BV / h. ③After the column is completed, further distillation and purification are carried out. The distillation method uses intermittent distillation, the bottom of the kettle is charged, the distillation temperature is 90 ° C, and the middle 10-80% fraction is collected. ④The obtained fraction is then treated with a cation exchange resin column, with a processing capacity of 10BV and a flow rate of 10BV / h. After the treatment is completed, the sample of Example 4 is obtained.

[0043] Example 5

[0044] ①Use 10% nickel nitrate to soak macroporous strong acid cation exchange resin, the soaking amount is m(10% nickel nitrate):m(cation resin)=1:1, the soaking time is 1 day, after the soaking, rinse the resin with pure water, and then use vacuum drying, vacuum drying at 45℃ for 6h, after the treatment, it is ready for use, and is recorded as "Ni exchange resin". ②Use 50% hydroxylamine solution to soak macroporous strong acid cation exchange resin, the soaking ratio is m(50% hydroxylamine):m(cation resin)=1:1, the soaking time is 1 day, after the soaking, rinse the resin with pure water, and then use vacuum drying, vacuum drying at 45℃ for 6h, after the treatment, it is ready for use, and is recorded as "HA exchange resin". ③The vacuum dried HA exchange resin is used to treat IPA raw materials by column passing, with a processing amount of 10BV and a flow rate of 10BV / h. After the column passing, it is further distilled and purified, and the distillation method uses intermittent distillation, bottom feeding, distillation temperature 90℃, and collects 10-80% of the middle fraction. ④ The collected fractions were then treated with the vacuum dried Ni exchange resin in a column manner, with a treatment volume of 10 BV and a flow rate of 10 BV / h. After the treatment, the sample of Example 5 was obtained.

[0045] Example 6

[0046] ①Use 10% nickel nitrate to soak macroporous strong acid cation exchange resin, the soaking amount is m(10% nickel nitrate):m(cation resin)=1:1, the soaking time is 1 day, after the soaking, rinse the resin with pure water, and then use vacuum drying, vacuum drying at 45℃ for 6h, after the treatment, it is ready for use, and is recorded as "Ni exchange resin". ②Use 50% hydroxylamine solution to soak macroporous strong acid cation exchange resin, the soaking ratio is m(50% hydroxylamine):m(cation resin)=1:1, the soaking time is 1 day, after the soaking, rinse the resin with pure water, and then use vacuum drying, vacuum drying at 45℃ for 6h, after the treatment, it is ready for use, and is recorded as "HA exchange resin". ③The vacuum dried HA exchange resin is used to treat IPA raw materials by column passing, with a processing amount of 10BV and a flow rate of 10BV / h. After the column passing, it is further distilled and purified, and the distillation method uses intermittent distillation, bottom feeding, distillation temperature 90℃, and collects 10-80% of the middle fraction. ④ The collected fractions were then treated with the vacuum dried Ni exchange resin in a column manner, with a treatment volume of 10 BV and a flow rate of 10 BV / h. ⑤ The treated sample was then treated with a cation exchange resin, with a treatment volume of 10 BV and a flow rate of 10 BV / h, and the sample of Example 6 was obtained after the treatment.

[0047] Example 7

[0048] ① Use 68% concentrated nitric acid to pre-treat coconut shell activated carbon particles (particle size 2-4mm) by soaking + ultrasound to achieve activation treatment. The soaking ultrasound time is 30min. After the ultrasound is completed, use a 120℃ oven to dry for 3h for standby use. ② Use 50% hydroxylamine solution to soak macroporous strong acid cation exchange resin. The soaking ratio is m(50% hydroxylamine): m(cation resin) = 1:1. The soaking time is 1 day. After the soaking is completed, use pure water to rinse the resin, and then use vacuum drying. 45℃ vacuum drying for 6h, after the treatment is completed, it is ready for use and recorded as "HA exchange resin". ③ The vacuum dried HA exchange resin is used to treat IPA raw materials by column passing, with a processing capacity of 10BV and a flow rate of 10BV / h. After the column is completed, it is further distilled and purified. The distillation method uses intermittent distillation, bottom feeding, distillation temperature 90℃, and collects 10-80% of the middle fraction. ④ Use activated carbon adsorption to treat the IPA fraction. The treatment method is filtration treatment. The volume ratio of the activated carbon layer to IPA is 1:10. Repeat the filtration 10 times. After the treatment is completed, the sample of Example 7 is obtained.

[0049] Example 8

[0050] ① Rinse conventional clinoptilolite with IPA, repeatedly rinse for more than 3 times, rinse excess organic and salt ion impurities, put the clinoptilolite after rinsing into a muffle furnace, and roast at 600℃ for 6h to remove residual organic matter to activate the zeolite. ② Soak macroporous strong acid cation exchange resin with 50% hydroxylamine solution, the soaking ratio is m(50% hydroxylamine):m(cation resin)=1:1, soak for 1 day, rinse the resin with pure water after soaking, and then use vacuum drying, vacuum drying at 45℃ for 6h, and set aside after treatment, recorded as "HA exchange resin". ③ The vacuum dried HA exchange resin treats IPA raw materials by column passing, with a processing capacity of 10BV and a flow rate of 10BV / h. After the column is completed, further distillation and purification are carried out, and the distillation method uses intermittent distillation, bottom feeding, distillation temperature 90℃, and collects 10-80% of the middle fraction. ④ The IPA fraction was treated by adsorption using activated clinoptilolite. The treatment method was filtration treatment. The volume ratio of the zeolite layer to IPA was 1:10. The filtration was repeated 10 times. After the treatment was completed, the sample of Example 8 was obtained.

[0051] Comparative Example 1

[0052] The IPA raw material is directly distilled by intermittent distillation, with feeding at the bottom of the kettle and a distillation temperature of 90° C. The middle 10-80% fraction is collected to obtain the fraction as the sample of Comparative Example 1.

[0053] Comparative Example 2

[0054] ① The IPA raw material was distilled and purified, and the distillation method used intermittent distillation, the bottom of the kettle was added, the distillation temperature was 90°C, and the middle 10-80% fraction was collected. ② The obtained fraction was then treated with a cation exchange resin column, the treatment volume was 10BV, the flow rate was 10BV / h, and the comparative example 2 sample was obtained after the treatment was completed.

[0055] Comparative Example 3

[0056] ①Use 10% nickel nitrate to soak macroporous strong acid cation exchange resin, the soaking amount is m (10% nickel nitrate): m (cation resin) = 1: 1, the soaking time is 1 day, after the soaking is completed, use pure water to rinse the resin, and then use vacuum drying, vacuum drying at 45 ° C for 6h, after the treatment is completed, it is ready for use and recorded as "Ni exchange resin". ②IPA raw material is distilled and purified, the distillation method uses intermittent distillation, the bottom of the kettle is added, the distillation temperature is 90 ° C, and the middle 10-80% fraction is collected. ③The vacuum-dried Ni exchange resin is used to process the collected fraction by column, the processing volume is 10BV, the flow rate is 10BV / h, and the comparative example 3 sample is obtained after the treatment.

[0057] Comparative Example 4

[0058] ① Use 68% concentrated nitric acid to pre-treat coconut shell activated carbon particles (particle size 2-4mm) by soaking + ultrasound to achieve activation treatment. The soaking ultrasound time is 30min. After the ultrasound is completed, use a 120℃ oven to dry for 3h for standby use. ② IPA raw material distillation and purification, the distillation method uses intermittent distillation, the bottom of the kettle is added, the distillation temperature is 90℃, and the middle 10-80% fraction is collected. ③ Use activated carbon adsorption to treat the IPA fraction, the treatment method is filtration treatment, the volume ratio of the activated carbon layer to IPA is 1:10, and it is filtered repeatedly 10 times. After the treatment is completed, the comparative example 4 sample is obtained.

[0059] Gas chromatography and ICP-MS were used to analyze the relevant impurity content and metal ion content in the products of the above embodiments and comparative examples.

[0060] Taking the product of Example 3, IPA raw material and 1 ppm acetone spike (1 ppm acetone was added to the acetonitrile sample as a standard solution) as an example, the gas chromatogram is as follows: Figure 1 As shown in the figure, the framed area is the acetone peak position, and the highest peak is the acetone peak in the IPA raw material. The "1ppm acetone spike" is used to locate the peak position and peak height as a reference. After the IPA raw material is treated by reaction, the acetone peak has disappeared, and the test result is 0ppm.

[0061] The test results of relevant impurity content and metal ion content are shown in Table 1:

[0062] Table 1

[0063]

[0064]

[0065] The above results show that after the IPA raw material containing acetone is treated by the method of the present invention (Examples 1 to 8), the acetone is completely reacted, and most of the by-products, impurities and metal ions are removed after ordinary distillation separation. Further using ion exchange, adsorption and other methods, the distillation product can be purified to varying degrees, so that acetone / acetone oxime / hydroxylamine and metal ions are removed. In the embodiment in which the last step is ion exchange resin column treatment, the metal ions can be reduced to less than 1 ppb, reaching the specification level of high-purity electronic grade isopropyl alcohol.

[0066] In Comparative Examples 1 to 4, directly using ordinary distillation, or further using ion exchange, adsorption, etc. after distillation, acetone cannot be completely removed and the acetone content cannot be reduced to 0 ppm.

[0067] In summary, the present invention removes acetone by converting acetone in isopropanol into acetone oxime having a large boiling point difference from isopropanol, and the removal rate can reach 100%, and other impurities and metal ions can be effectively removed, so as to prepare isopropanol with high-purity electronic grade specifications.

[0068] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0069] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all 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 removing acetone from isopropanol, characterized in that: The following steps are involved: S1. converting acetone in isopropanol into acetone oxime; S2. distilling the product obtained in step S1.

2. The method according to claim 1, characterized in that Step S1 is to react isopropanol containing acetone with hydroxylamine and / or hydroxylamine salt; or The isopropanol containing acetone is contacted with the carrier connected with the hydroxylamine group to make the acetone react with the hydroxylamine group.

3. The method according to claim 2, characterized in that The carrier is a cation exchange resin.

4. The method according to claim 3, characterized in that Step S1 comprises the following steps: (1) pre-treating hydroxylamine with a cation exchange resin to obtain a cation exchange resin connected with a hydroxylamine group; (2) washing and drying the cation exchange resin connected with a hydroxylamine group; and (3) using the cation exchange resin obtained in step (2) to perform column chromatography on isopropanol containing acetone.

5. The method according to claim 4, characterized in that The pretreatment reaction in step (1) is: soaking the cation exchange resin in a hydroxylamine solution for 2 hours to 48 hours; and / or, The flow rate of the isopropanol containing acetone during the treatment process of step (3) is 1 BV / h to 20 BV / h.

6. The method according to claim 1, characterized in that The distillation in step S2 is intermittent distillation.

7. The method according to any one of claims 1 to 6, characterized in that: The step S3 is to perform column chromatography on the distillation product using a cation exchange resin; or The distillation product is treated with molecular sieve or activated carbon.

8. The method according to claim 7, characterized in that The molecular sieve is at least one of clinoptilolite, mordenite, Y-type zeolite, Beta-type zeolite and MFI-type zeolite; and / or, The activated carbon is selected from at least one of columnar particles and coconut shell particles, and the particle size of the activated carbon is 0.5 mm to 6 mm.

9. The method according to claim 7, characterized in that The cation exchange resin is pretreated as follows before use: the cation exchange resin is soaked in a salt solution of a chelating metal for 2 hours to 48 hours, and then washed and dried; the salt is selected from at least one of nitrate, hydrochloride and sulfate; and / or, The flow rate of the distillation product during the treatment process is 1 BV / h to 20 BV / h.

10. The method according to claim 9, characterized in that The chelating metal is selected from at least one of Ni, Co, Ca, Zn, Fe, Cu and Mg.

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